Merge branch 'gallium-0.1' into gallium-0.2

A first attempt at moving gallium onto a branch directly off master...

It will be interesting to see how much work this takes to get running.

Have resolved the conflicts semi-arbitarily, not compiled or tested.

Conflicts:

	.gitignore
	Makefile
	configs/config.mgw
	configs/darwin
	configs/darwin-x86ppc
	configs/default
	configs/freebsd-dri
	configs/linux-dri
	configs/linux-dri-xcb
	configs/linux-fbdev
	configs/linux-static
	configs/linux-x86-64-static
	configs/linux-x86-static
	doxygen/Makefile
	include/GL/gl.h
	progs/demos/Makefile
	progs/demos/descrip.mms
	progs/demos/texenv.c
	progs/egl/.gitignore
	progs/egl/Makefile
	progs/glsl/.gitignore
	progs/glsl/Makefile
	progs/glsl/convolutions.c
	progs/samples/Makefile.mgw
	progs/tests/.gitignore
	progs/trivial/.gitignore
	progs/trivial/point-param.c
	progs/trivial/tri.c
	progs/xdemos/.gitignore
	progs/xdemos/glthreads.c
	src/egl/drivers/demo/Makefile
	src/egl/drivers/dri/Makefile
	src/egl/main/Makefile
	src/glu/Makefile
	src/glu/sgi/Makefile
	src/glu/sgi/Makefile.mgw
	src/glut/glx/Makefile.mgw
	src/glut/os2/WarpWin.cpp
	src/glut/os2/glut_cindex.cpp
	src/glut/os2/glut_gamemode.cpp
	src/glut/os2/glut_win.cpp
	src/glut/os2/glut_winmisc.cpp
	src/glut/os2/os2_glx.cpp
	src/glut/os2/os2_menu.cpp
	src/glut/os2/os2_winproc.cpp
	src/glw/Makefile
	src/glx/x11/dri_glx.c
	src/glx/x11/glxext.c
	src/mesa/Makefile
	src/mesa/Makefile.mgw
	src/mesa/descrip.mms
	src/mesa/drivers/beos/Makefile
	src/mesa/drivers/common/descrip.mms
	src/mesa/drivers/common/driverfuncs.c
	src/mesa/drivers/directfb/Makefile
	src/mesa/drivers/dri/Makefile.template
	src/mesa/drivers/dri/common/dri_bufmgr.c
	src/mesa/drivers/dri/common/dri_bufmgr.h
	src/mesa/drivers/dri/common/dri_util.c
	src/mesa/drivers/dri/common/extension_helper.h
	src/mesa/drivers/dri/common/mmio.h
	src/mesa/drivers/dri/common/utils.c
	src/mesa/drivers/dri/common/utils.h
	src/mesa/drivers/dri/glcore/Makefile
	src/mesa/drivers/dri/i810/i810screen.c
	src/mesa/drivers/dri/i915/intel_ioctl.c
	src/mesa/drivers/dri/i915/intel_ioctl.h
	src/mesa/drivers/dri/i915/intel_screen.c
	src/mesa/drivers/dri/i915/server/i830_common.h
	src/mesa/drivers/dri/i915/server/i830_dri.h
	src/mesa/drivers/dri/i965/intel_screen.c
	src/mesa/drivers/dri/i965/server/i830_common.h
	src/mesa/drivers/dri/i965/server/i830_dri.h
	src/mesa/drivers/dri/mach64/mach64_screen.c
	src/mesa/drivers/dri/nouveau/nouveau_context.h
	src/mesa/drivers/dri/nouveau/nouveau_fifo.c
	src/mesa/drivers/dri/nouveau/nouveau_fifo.h
	src/mesa/drivers/dri/nouveau/nouveau_screen.c
	src/mesa/drivers/dri/nouveau/nouveau_screen.h
	src/mesa/drivers/dri/r128/r128_tex.h
	src/mesa/drivers/dri/savage/savageioctl.h
	src/mesa/drivers/fbdev/Makefile
	src/mesa/drivers/osmesa/Makefile
	src/mesa/drivers/osmesa/descrip.mms
	src/mesa/drivers/x11/Makefile
	src/mesa/drivers/x11/descrip.mms
	src/mesa/drivers/x11/xm_dd.c
	src/mesa/glapi/glapi.c
	src/mesa/glapi/glthread.c
	src/mesa/main/api_validate.c
	src/mesa/main/attrib.c
	src/mesa/main/bufferobj.c
	src/mesa/main/bufferobj.h
	src/mesa/main/buffers.c
	src/mesa/main/config.h
	src/mesa/main/context.c
	src/mesa/main/descrip.mms
	src/mesa/main/drawpix.c
	src/mesa/main/enums.c
	src/mesa/main/fbobject.c
	src/mesa/main/glheader.h
	src/mesa/main/imports.c
	src/mesa/main/mipmap.c
	src/mesa/main/mm.c
	src/mesa/main/mm.h
	src/mesa/main/mtypes.h
	src/mesa/main/points.c
	src/mesa/main/sources
	src/mesa/main/state.c
	src/mesa/main/texcompress_fxt1.c
	src/mesa/main/texenvprogram.c
	src/mesa/main/texobj.c
	src/mesa/main/texstate.c
	src/mesa/main/texstore.c
	src/mesa/math/descrip.mms
	src/mesa/shader/arbprogram.c
	src/mesa/shader/descrip.mms
	src/mesa/shader/prog_execute.c
	src/mesa/shader/prog_statevars.c
	src/mesa/shader/prog_statevars.h
	src/mesa/shader/prog_uniform.c
	src/mesa/shader/program.c
	src/mesa/shader/program.h
	src/mesa/shader/shader_api.c
	src/mesa/shader/slang/descrip.mms
	src/mesa/shader/slang/library/slang_vertex_builtin_gc.h
	src/mesa/sources
	src/mesa/swrast/descrip.mms
	src/mesa/swrast/s_drawpix.c
	src/mesa/swrast/s_fragprog.c
	src/mesa/swrast/s_readpix.c
	src/mesa/swrast/s_span.c
	src/mesa/swrast_setup/descrip.mms
	src/mesa/tnl/descrip.mms
	src/mesa/tnl/t_context.h
	src/mesa/tnl/t_vp_build.c
	src/mesa/tnl/tnl.h
	src/mesa/vbo/descrip.mms
	src/mesa/vbo/vbo_context.c
	src/mesa/vbo/vbo_exec_array.c
	src/mesa/x86-64/xform4.S
	src/mesa/x86/rtasm/x86sse.c
	src/mesa/x86/rtasm/x86sse.h
	windows/VC6/progs/glut/glut.dsp
	windows/VC7/mesa/gdi/gdi.vcproj
	windows/VC7/mesa/glu/glu.vcproj
	windows/VC7/mesa/mesa.sln
	windows/VC7/mesa/mesa/mesa.vcproj
	windows/VC7/mesa/osmesa/osmesa.vcproj
	windows/VC7/progs/glut/glut.vcproj
	windows/VC8/mesa/gdi/gdi.vcproj
	windows/VC8/mesa/glu/glu.vcproj
	windows/VC8/mesa/mesa.sln
	windows/VC8/mesa/mesa/mesa.vcproj
	windows/VC8/progs/glut/glut.vcproj

1 files changed, 521 insertions, 548 deletions

diff --git a/src/mesa/main/mipmap.c b/src/mesa/main/mipmap.c
index 8ca912b3a9..1032e9bb72 100644
--- a/src/mesa/main/mipmap.c
+++ b/src/mesa/main/mipmap.c
@@ -36,462 +36,377 @@
 
 
 
+static GLint
+bytes_per_pixel(GLenum datatype, GLuint comps)
+{
+   GLint b = _mesa_sizeof_packed_type(datatype);
+   assert(b >= 0);
+   return b * comps;
+}
+
+
 /**
  * Average together two rows of a source image to produce a single new
  * row in the dest image.  It's legal for the two source rows to point
  * to the same data.  The source width must be equal to either the
  * dest width or two times the dest width.
+ * \param datatype  GL_UNSIGNED_BYTE, GL_UNSIGNED_SHORT, GL_FLOAT, etc.
+ * \param comps  number of components per pixel (1..4)
  */
 static void
-do_row(const struct gl_texture_format *format, GLint srcWidth,
+do_row(GLenum datatype, GLuint comps, GLint srcWidth,
        const GLvoid *srcRowA, const GLvoid *srcRowB,
        GLint dstWidth, GLvoid *dstRow)
 {
    const GLuint k0 = (srcWidth == dstWidth) ? 0 : 1;
    const GLuint colStride = (srcWidth == dstWidth) ? 1 : 2;
 
+   ASSERT(comps >= 1);
+   ASSERT(comps <= 4);
+
    /* This assertion is no longer valid with non-power-of-2 textures
    assert(srcWidth == dstWidth || srcWidth == 2 * dstWidth);
    */
 
-   switch (format->MesaFormat) {
-   case MESA_FORMAT_RGBA:
-      {
-         GLuint i, j, k;
-         const GLchan (*rowA)[4] = (const GLchan (*)[4]) srcRowA;
-         const GLchan (*rowB)[4] = (const GLchan (*)[4]) srcRowB;
-         GLchan (*dst)[4] = (GLchan (*)[4]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i][0] = (rowA[j][0] + rowA[k][0] +
-                         rowB[j][0] + rowB[k][0]) / 4;
-            dst[i][1] = (rowA[j][1] + rowA[k][1] +
-                         rowB[j][1] + rowB[k][1]) / 4;
-            dst[i][2] = (rowA[j][2] + rowA[k][2] +
-                         rowB[j][2] + rowB[k][2]) / 4;
-            dst[i][3] = (rowA[j][3] + rowA[k][3] +
-                         rowB[j][3] + rowB[k][3]) / 4;
-         }
+   if (datatype == GL_UNSIGNED_BYTE && comps == 4) {
+      GLuint i, j, k;
+      const GLubyte(*rowA)[4] = (const GLubyte(*)[4]) srcRowA;
+      const GLubyte(*rowB)[4] = (const GLubyte(*)[4]) srcRowB;
+      GLubyte(*dst)[4] = (GLubyte(*)[4]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
+         dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
+         dst[i][3] = (rowA[j][3] + rowA[k][3] + rowB[j][3] + rowB[k][3]) / 4;
       }
-      return;
-   case MESA_FORMAT_RGB:
-      {
-         GLuint i, j, k;
-         const GLchan (*rowA)[3] = (const GLchan (*)[3]) srcRowA;
-         const GLchan (*rowB)[3] = (const GLchan (*)[3]) srcRowB;
-         GLchan (*dst)[3] = (GLchan (*)[3]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i][0] = (rowA[j][0] + rowA[k][0] +
-                         rowB[j][0] + rowB[k][0]) / 4;
-            dst[i][1] = (rowA[j][1] + rowA[k][1] +
-                         rowB[j][1] + rowB[k][1]) / 4;
-            dst[i][2] = (rowA[j][2] + rowA[k][2] +
-                         rowB[j][2] + rowB[k][2]) / 4;
-         }
-      }
-      return;
-   case MESA_FORMAT_ALPHA:
-   case MESA_FORMAT_LUMINANCE:
-   case MESA_FORMAT_INTENSITY:
-      {
-         GLuint i, j, k;
-         const GLchan *rowA = (const GLchan *) srcRowA;
-         const GLchan *rowB = (const GLchan *) srcRowB;
-         GLchan *dst = (GLchan *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) / 4;
-         }
+   }
+   else if (datatype == GL_UNSIGNED_BYTE && comps == 3) {
+      GLuint i, j, k;
+      const GLubyte(*rowA)[3] = (const GLubyte(*)[3]) srcRowA;
+      const GLubyte(*rowB)[3] = (const GLubyte(*)[3]) srcRowB;
+      GLubyte(*dst)[3] = (GLubyte(*)[3]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
+         dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
       }
-      return;
-   case MESA_FORMAT_LUMINANCE_ALPHA:
-      {
-         GLuint i, j, k;
-         const GLchan (*rowA)[2] = (const GLchan (*)[2]) srcRowA;
-         const GLchan (*rowB)[2] = (const GLchan (*)[2]) srcRowB;
-         GLchan (*dst)[2] = (GLchan (*)[2]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i][0] = (rowA[j][0] + rowA[k][0] +
-                         rowB[j][0] + rowB[k][0]) / 4;
-            dst[i][1] = (rowA[j][1] + rowA[k][1] +
-                         rowB[j][1] + rowB[k][1]) / 4;
-         }
+   }
+   else if (datatype == GL_UNSIGNED_BYTE && comps == 2) {
+      GLuint i, j, k;
+      const GLubyte(*rowA)[2] = (const GLubyte(*)[2]) srcRowA;
+      const GLubyte(*rowB)[2] = (const GLubyte(*)[2]) srcRowB;
+      GLubyte(*dst)[2] = (GLubyte(*)[2]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) >> 2;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) >> 2;
       }
-      return;
-   case MESA_FORMAT_Z32:
-      {
-         GLuint i, j, k;
-         const GLuint *rowA = (const GLuint *) srcRowA;
-         const GLuint *rowB = (const GLuint *) srcRowB;
-         GLfloat *dst = (GLfloat *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i] = rowA[j] / 4 + rowA[k] / 4 + rowB[j] / 4 + rowB[k] / 4;
-         }
+   }
+   else if (datatype == GL_UNSIGNED_BYTE && comps == 1) {
+      GLuint i, j, k;
+      const GLubyte *rowA = (const GLubyte *) srcRowA;
+      const GLubyte *rowB = (const GLubyte *) srcRowB;
+      GLubyte *dst = (GLubyte *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) >> 2;
       }
-      return;
-   case MESA_FORMAT_Z16:
-      {
-         GLuint i, j, k;
-         const GLushort *rowA = (const GLushort *) srcRowA;
-         const GLushort *rowB = (const GLushort *) srcRowB;
-         GLushort *dst = (GLushort *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) / 4;
-         }
+   }
+
+   else if (datatype == GL_UNSIGNED_SHORT && comps == 4) {
+      GLuint i, j, k;
+      const GLushort(*rowA)[4] = (const GLushort(*)[4]) srcRowA;
+      const GLushort(*rowB)[4] = (const GLushort(*)[4]) srcRowB;
+      GLushort(*dst)[4] = (GLushort(*)[4]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
+         dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
+         dst[i][3] = (rowA[j][3] + rowA[k][3] + rowB[j][3] + rowB[k][3]) / 4;
       }
-      return;
-   /* Begin hardware formats */
-   case MESA_FORMAT_RGBA8888:
-   case MESA_FORMAT_RGBA8888_REV:
-   case MESA_FORMAT_ARGB8888:
-   case MESA_FORMAT_ARGB8888_REV:
-#if FEATURE_EXT_texture_sRGB
-   case MESA_FORMAT_SRGBA8:
-#endif
-      {
-         GLuint i, j, k;
-         const GLubyte (*rowA)[4] = (const GLubyte (*)[4]) srcRowA;
-         const GLubyte (*rowB)[4] = (const GLubyte (*)[4]) srcRowB;
-         GLubyte (*dst)[4] = (GLubyte (*)[4]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i][0] = (rowA[j][0] + rowA[k][0] +
-                         rowB[j][0] + rowB[k][0]) / 4;
-            dst[i][1] = (rowA[j][1] + rowA[k][1] +
-                         rowB[j][1] + rowB[k][1]) / 4;
-            dst[i][2] = (rowA[j][2] + rowA[k][2] +
-                         rowB[j][2] + rowB[k][2]) / 4;
-            dst[i][3] = (rowA[j][3] + rowA[k][3] +
-                         rowB[j][3] + rowB[k][3]) / 4;
-         }
+   }
+   else if (datatype == GL_UNSIGNED_SHORT && comps == 3) {
+      GLuint i, j, k;
+      const GLushort(*rowA)[3] = (const GLushort(*)[3]) srcRowA;
+      const GLushort(*rowB)[3] = (const GLushort(*)[3]) srcRowB;
+      GLushort(*dst)[3] = (GLushort(*)[3]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
+         dst[i][2] = (rowA[j][2] + rowA[k][2] + rowB[j][2] + rowB[k][2]) / 4;
       }
-      return;
-   case MESA_FORMAT_RGB888:
-   case MESA_FORMAT_BGR888:
-#if FEATURE_EXT_texture_sRGB
-   case MESA_FORMAT_SRGB8:
-#endif
-      {
-         GLuint i, j, k;
-         const GLubyte (*rowA)[3] = (const GLubyte (*)[3]) srcRowA;
-         const GLubyte (*rowB)[3] = (const GLubyte (*)[3]) srcRowB;
-         GLubyte (*dst)[3] = (GLubyte (*)[3]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i][0] = (rowA[j][0] + rowA[k][0] +
-                         rowB[j][0] + rowB[k][0]) / 4;
-            dst[i][1] = (rowA[j][1] + rowA[k][1] +
-                         rowB[j][1] + rowB[k][1]) / 4;
-            dst[i][2] = (rowA[j][2] + rowA[k][2] +
-                         rowB[j][2] + rowB[k][2]) / 4;
-         }
+   }
+   else if (datatype == GL_UNSIGNED_SHORT && comps == 2) {
+      GLuint i, j, k;
+      const GLushort(*rowA)[2] = (const GLushort(*)[2]) srcRowA;
+      const GLushort(*rowB)[2] = (const GLushort(*)[2]) srcRowB;
+      GLushort(*dst)[2] = (GLushort(*)[2]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] + rowB[j][0] + rowB[k][0]) / 4;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] + rowB[j][1] + rowB[k][1]) / 4;
       }
-      return;
-   case MESA_FORMAT_RGB565:
-   case MESA_FORMAT_RGB565_REV:
-      {
-         GLuint i, j, k;
-         const GLushort *rowA = (const GLushort *) srcRowA;
-         const GLushort *rowB = (const GLushort *) srcRowB;
-         GLushort *dst = (GLushort *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            const GLint rowAr0 = rowA[j] & 0x1f;
-            const GLint rowAr1 = rowA[k] & 0x1f;
-            const GLint rowBr0 = rowB[j] & 0x1f;
-            const GLint rowBr1 = rowB[k] & 0x1f;
-            const GLint rowAg0 = (rowA[j] >> 5) & 0x3f;
-            const GLint rowAg1 = (rowA[k] >> 5) & 0x3f;
-            const GLint rowBg0 = (rowB[j] >> 5) & 0x3f;
-            const GLint rowBg1 = (rowB[k] >> 5) & 0x3f;
-            const GLint rowAb0 = (rowA[j] >> 11) & 0x1f;
-            const GLint rowAb1 = (rowA[k] >> 11) & 0x1f;
-            const GLint rowBb0 = (rowB[j] >> 11) & 0x1f;
-            const GLint rowBb1 = (rowB[k] >> 11) & 0x1f;
-            const GLint red   = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
-            const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
-            const GLint blue  = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
-            dst[i] = (blue << 11) | (green << 5) | red;
-         }
+   }
+   else if (datatype == GL_UNSIGNED_SHORT && comps == 1) {
+      GLuint i, j, k;
+      const GLushort *rowA = (const GLushort *) srcRowA;
+      const GLushort *rowB = (const GLushort *) srcRowB;
+      GLushort *dst = (GLushort *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) / 4;
       }
-      return;
-   case MESA_FORMAT_ARGB4444:
-   case MESA_FORMAT_ARGB4444_REV:
-      {
-         GLuint i, j, k;
-         const GLushort *rowA = (const GLushort *) srcRowA;
-         const GLushort *rowB = (const GLushort *) srcRowB;
-         GLushort *dst = (GLushort *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            const GLint rowAr0 = rowA[j] & 0xf;
-            const GLint rowAr1 = rowA[k] & 0xf;
-            const GLint rowBr0 = rowB[j] & 0xf;
-            const GLint rowBr1 = rowB[k] & 0xf;
-            const GLint rowAg0 = (rowA[j] >> 4) & 0xf;
-            const GLint rowAg1 = (rowA[k] >> 4) & 0xf;
-            const GLint rowBg0 = (rowB[j] >> 4) & 0xf;
-            const GLint rowBg1 = (rowB[k] >> 4) & 0xf;
-            const GLint rowAb0 = (rowA[j] >> 8) & 0xf;
-            const GLint rowAb1 = (rowA[k] >> 8) & 0xf;
-            const GLint rowBb0 = (rowB[j] >> 8) & 0xf;
-            const GLint rowBb1 = (rowB[k] >> 8) & 0xf;
-            const GLint rowAa0 = (rowA[j] >> 12) & 0xf;
-            const GLint rowAa1 = (rowA[k] >> 12) & 0xf;
-            const GLint rowBa0 = (rowB[j] >> 12) & 0xf;
-            const GLint rowBa1 = (rowB[k] >> 12) & 0xf;
-            const GLint red   = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
-            const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
-            const GLint blue  = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
-            const GLint alpha = (rowAa0 + rowAa1 + rowBa0 + rowBa1) >> 2;
-            dst[i] = (alpha << 12) | (blue << 8) | (green << 4) | red;
-         }
+   }
+
+   else if (datatype == GL_FLOAT && comps == 4) {
+      GLuint i, j, k;
+      const GLfloat(*rowA)[4] = (const GLfloat(*)[4]) srcRowA;
+      const GLfloat(*rowB)[4] = (const GLfloat(*)[4]) srcRowB;
+      GLfloat(*dst)[4] = (GLfloat(*)[4]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] +
+                      rowB[j][0] + rowB[k][0]) * 0.25F;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] +
+                      rowB[j][1] + rowB[k][1]) * 0.25F;
+         dst[i][2] = (rowA[j][2] + rowA[k][2] +
+                      rowB[j][2] + rowB[k][2]) * 0.25F;
+         dst[i][3] = (rowA[j][3] + rowA[k][3] +
+                      rowB[j][3] + rowB[k][3]) * 0.25F;
       }
-      return;
-   case MESA_FORMAT_ARGB1555:
-   case MESA_FORMAT_ARGB1555_REV: /* XXX broken? */
-      {
-         GLuint i, j, k;
-         const GLushort *rowA = (const GLushort *) srcRowA;
-         const GLushort *rowB = (const GLushort *) srcRowB;
-         GLushort *dst = (GLushort *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            const GLint rowAr0 = rowA[j] & 0x1f;
-            const GLint rowAr1 = rowA[k] & 0x1f;
-            const GLint rowBr0 = rowB[j] & 0x1f;
-            const GLint rowBr1 = rowB[k] & 0xf;
-            const GLint rowAg0 = (rowA[j] >> 5) & 0x1f;
-            const GLint rowAg1 = (rowA[k] >> 5) & 0x1f;
-            const GLint rowBg0 = (rowB[j] >> 5) & 0x1f;
-            const GLint rowBg1 = (rowB[k] >> 5) & 0x1f;
-            const GLint rowAb0 = (rowA[j] >> 10) & 0x1f;
-            const GLint rowAb1 = (rowA[k] >> 10) & 0x1f;
-            const GLint rowBb0 = (rowB[j] >> 10) & 0x1f;
-            const GLint rowBb1 = (rowB[k] >> 10) & 0x1f;
-            const GLint rowAa0 = (rowA[j] >> 15) & 0x1;
-            const GLint rowAa1 = (rowA[k] >> 15) & 0x1;
-            const GLint rowBa0 = (rowB[j] >> 15) & 0x1;
-            const GLint rowBa1 = (rowB[k] >> 15) & 0x1;
-            const GLint red   = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
-            const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
-            const GLint blue  = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
-            const GLint alpha = (rowAa0 + rowAa1 + rowBa0 + rowBa1) >> 2;
-            dst[i] = (alpha << 15) | (blue << 10) | (green << 5) | red;
-         }
+   }
+   else if (datatype == GL_FLOAT && comps == 3) {
+      GLuint i, j, k;
+      const GLfloat(*rowA)[3] = (const GLfloat(*)[3]) srcRowA;
+      const GLfloat(*rowB)[3] = (const GLfloat(*)[3]) srcRowB;
+      GLfloat(*dst)[3] = (GLfloat(*)[3]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] +
+                      rowB[j][0] + rowB[k][0]) * 0.25F;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] +
+                      rowB[j][1] + rowB[k][1]) * 0.25F;
+         dst[i][2] = (rowA[j][2] + rowA[k][2] +
+                      rowB[j][2] + rowB[k][2]) * 0.25F;
       }
-      return;
-   case MESA_FORMAT_AL88:
-   case MESA_FORMAT_AL88_REV:
-#if FEATURE_EXT_texture_sRGB
-   case MESA_FORMAT_SLA8:
-#endif
-      {
-         GLuint i, j, k;
-         const GLubyte (*rowA)[2] = (const GLubyte (*)[2]) srcRowA;
-         const GLubyte (*rowB)[2] = (const GLubyte (*)[2]) srcRowB;
-         GLubyte (*dst)[2] = (GLubyte (*)[2]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i][0] = (rowA[j][0] + rowA[k][0] +
-                         rowB[j][0] + rowB[k][0]) >> 2;
-            dst[i][1] = (rowA[j][1] + rowA[k][1] +
-                         rowB[j][1] + rowB[k][1]) >> 2;
-         }
+   }
+   else if (datatype == GL_FLOAT && comps == 2) {
+      GLuint i, j, k;
+      const GLfloat(*rowA)[2] = (const GLfloat(*)[2]) srcRowA;
+      const GLfloat(*rowB)[2] = (const GLfloat(*)[2]) srcRowB;
+      GLfloat(*dst)[2] = (GLfloat(*)[2]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i][0] = (rowA[j][0] + rowA[k][0] +
+                      rowB[j][0] + rowB[k][0]) * 0.25F;
+         dst[i][1] = (rowA[j][1] + rowA[k][1] +
+                      rowB[j][1] + rowB[k][1]) * 0.25F;
       }
-      return;
-   case MESA_FORMAT_RGB332:
-      {
-         GLuint i, j, k;
-         const GLubyte *rowA = (const GLubyte *) srcRowA;
-         const GLubyte *rowB = (const GLubyte *) srcRowB;
-         GLubyte *dst = (GLubyte *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            const GLint rowAr0 = rowA[j] & 0x3;
-            const GLint rowAr1 = rowA[k] & 0x3;
-            const GLint rowBr0 = rowB[j] & 0x3;
-            const GLint rowBr1 = rowB[k] & 0x3;
-            const GLint rowAg0 = (rowA[j] >> 2) & 0x7;
-            const GLint rowAg1 = (rowA[k] >> 2) & 0x7;
-            const GLint rowBg0 = (rowB[j] >> 2) & 0x7;
-            const GLint rowBg1 = (rowB[k] >> 2) & 0x7;
-            const GLint rowAb0 = (rowA[j] >> 5) & 0x7;
-            const GLint rowAb1 = (rowA[k] >> 5) & 0x7;
-            const GLint rowBb0 = (rowB[j] >> 5) & 0x7;
-            const GLint rowBb1 = (rowB[k] >> 5) & 0x7;
-            const GLint red   = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
-            const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
-            const GLint blue  = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
-            dst[i] = (blue << 5) | (green << 2) | red;
-         }
+   }
+   else if (datatype == GL_FLOAT && comps == 1) {
+      GLuint i, j, k;
+      const GLfloat *rowA = (const GLfloat *) srcRowA;
+      const GLfloat *rowB = (const GLfloat *) srcRowB;
+      GLfloat *dst = (GLfloat *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) * 0.25F;
       }
-      return;
-   case MESA_FORMAT_A8:
-   case MESA_FORMAT_L8:
-   case MESA_FORMAT_I8:
-   case MESA_FORMAT_CI8:
-#if FEATURE_EXT_texture_sRGB
-   case MESA_FORMAT_SL8:
-#endif
-      {
-         GLuint i, j, k;
-         const GLubyte *rowA = (const GLubyte *) srcRowA;
-         const GLubyte *rowB = (const GLubyte *) srcRowB;
-         GLubyte *dst = (GLubyte *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) >> 2;
+   }
+
+   else if (datatype == GL_HALF_FLOAT_ARB && comps == 4) {
+      GLuint i, j, k, comp;
+      const GLhalfARB(*rowA)[4] = (const GLhalfARB(*)[4]) srcRowA;
+      const GLhalfARB(*rowB)[4] = (const GLhalfARB(*)[4]) srcRowB;
+      GLhalfARB(*dst)[4] = (GLhalfARB(*)[4]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         for (comp = 0; comp < 4; comp++) {
+            GLfloat aj, ak, bj, bk;
+            aj = _mesa_half_to_float(rowA[j][comp]);
+            ak = _mesa_half_to_float(rowA[k][comp]);
+            bj = _mesa_half_to_float(rowB[j][comp]);
+            bk = _mesa_half_to_float(rowB[k][comp]);
+            dst[i][comp] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
          }
       }
-      return;
-   case MESA_FORMAT_RGBA_FLOAT32:
-      {
-         GLuint i, j, k;
-         const GLfloat (*rowA)[4] = (const GLfloat (*)[4]) srcRowA;
-         const GLfloat (*rowB)[4] = (const GLfloat (*)[4]) srcRowB;
-         GLfloat (*dst)[4] = (GLfloat (*)[4]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i][0] = (rowA[j][0] + rowA[k][0] +
-                         rowB[j][0] + rowB[k][0]) * 0.25F;
-            dst[i][1] = (rowA[j][1] + rowA[k][1] +
-                         rowB[j][1] + rowB[k][1]) * 0.25F;
-            dst[i][2] = (rowA[j][2] + rowA[k][2] +
-                         rowB[j][2] + rowB[k][2]) * 0.25F;
-            dst[i][3] = (rowA[j][3] + rowA[k][3] +
-                         rowB[j][3] + rowB[k][3]) * 0.25F;
+   }
+   else if (datatype == GL_HALF_FLOAT_ARB && comps == 3) {
+      GLuint i, j, k, comp;
+      const GLhalfARB(*rowA)[3] = (const GLhalfARB(*)[3]) srcRowA;
+      const GLhalfARB(*rowB)[3] = (const GLhalfARB(*)[3]) srcRowB;
+      GLhalfARB(*dst)[3] = (GLhalfARB(*)[3]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         for (comp = 0; comp < 3; comp++) {
+            GLfloat aj, ak, bj, bk;
+            aj = _mesa_half_to_float(rowA[j][comp]);
+            ak = _mesa_half_to_float(rowA[k][comp]);
+            bj = _mesa_half_to_float(rowB[j][comp]);
+            bk = _mesa_half_to_float(rowB[k][comp]);
+            dst[i][comp] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
          }
       }
-      return;
-   case MESA_FORMAT_RGBA_FLOAT16:
-      {
-         GLuint i, j, k, comp;
-         const GLhalfARB (*rowA)[4] = (const GLhalfARB (*)[4]) srcRowA;
-         const GLhalfARB (*rowB)[4] = (const GLhalfARB (*)[4]) srcRowB;
-         GLhalfARB (*dst)[4] = (GLhalfARB (*)[4]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            for (comp = 0; comp < 4; comp++) {
-               GLfloat aj, ak, bj, bk;
-               aj = _mesa_half_to_float(rowA[j][comp]);
-               ak = _mesa_half_to_float(rowA[k][comp]);
-               bj = _mesa_half_to_float(rowB[j][comp]);
-               bk = _mesa_half_to_float(rowB[k][comp]);
-               dst[i][comp] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
-            }
+   }
+   else if (datatype == GL_HALF_FLOAT_ARB && comps == 2) {
+      GLuint i, j, k, comp;
+      const GLhalfARB(*rowA)[2] = (const GLhalfARB(*)[2]) srcRowA;
+      const GLhalfARB(*rowB)[2] = (const GLhalfARB(*)[2]) srcRowB;
+      GLhalfARB(*dst)[2] = (GLhalfARB(*)[2]) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         for (comp = 0; comp < 2; comp++) {
+            GLfloat aj, ak, bj, bk;
+            aj = _mesa_half_to_float(rowA[j][comp]);
+            ak = _mesa_half_to_float(rowA[k][comp]);
+            bj = _mesa_half_to_float(rowB[j][comp]);
+            bk = _mesa_half_to_float(rowB[k][comp]);
+            dst[i][comp] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
          }
       }
-      return;
-   case MESA_FORMAT_RGB_FLOAT32:
-      {
-         GLuint i, j, k;
-         const GLfloat (*rowA)[3] = (const GLfloat (*)[3]) srcRowA;
-         const GLfloat (*rowB)[3] = (const GLfloat (*)[3]) srcRowB;
-         GLfloat (*dst)[3] = (GLfloat (*)[3]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i][0] = (rowA[j][0] + rowA[k][0] +
-                         rowB[j][0] + rowB[k][0]) * 0.25F;
-            dst[i][1] = (rowA[j][1] + rowA[k][1] +
-                         rowB[j][1] + rowB[k][1]) * 0.25F;
-            dst[i][2] = (rowA[j][2] + rowA[k][2] +
-                         rowB[j][2] + rowB[k][2]) * 0.25F;
-         }
+   }
+   else if (datatype == GL_HALF_FLOAT_ARB && comps == 1) {
+      GLuint i, j, k;
+      const GLhalfARB *rowA = (const GLhalfARB *) srcRowA;
+      const GLhalfARB *rowB = (const GLhalfARB *) srcRowB;
+      GLhalfARB *dst = (GLhalfARB *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         GLfloat aj, ak, bj, bk;
+         aj = _mesa_half_to_float(rowA[j]);
+         ak = _mesa_half_to_float(rowA[k]);
+         bj = _mesa_half_to_float(rowB[j]);
+         bk = _mesa_half_to_float(rowB[k]);
+         dst[i] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
       }
-      return;
-   case MESA_FORMAT_RGB_FLOAT16:
-      {
-         GLuint i, j, k, comp;
-         const GLhalfARB (*rowA)[3] = (const GLhalfARB (*)[3]) srcRowA;
-         const GLhalfARB (*rowB)[3] = (const GLhalfARB (*)[3]) srcRowB;
-         GLhalfARB (*dst)[3] = (GLhalfARB (*)[3]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            for (comp = 0; comp < 3; comp++) {
-               GLfloat aj, ak, bj, bk;
-               aj = _mesa_half_to_float(rowA[j][comp]);
-               ak = _mesa_half_to_float(rowA[k][comp]);
-               bj = _mesa_half_to_float(rowB[j][comp]);
-               bk = _mesa_half_to_float(rowB[k][comp]);
-               dst[i][comp] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
-            }
-         }
+   }
+
+   else if (datatype == GL_UNSIGNED_INT && comps == 1) {
+      GLuint i, j, k;
+      const GLuint *rowA = (const GLuint *) srcRowA;
+      const GLuint *rowB = (const GLuint *) srcRowB;
+      GLfloat *dst = (GLfloat *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         dst[i] = (GLfloat)(rowA[j] / 4 + rowA[k] / 4 + rowB[j] / 4 + rowB[k] / 4);
       }
-      return;
-   case MESA_FORMAT_LUMINANCE_ALPHA_FLOAT32:
-      {
-         GLuint i, j, k;
-         const GLfloat (*rowA)[2] = (const GLfloat (*)[2]) srcRowA;
-         const GLfloat (*rowB)[2] = (const GLfloat (*)[2]) srcRowB;
-         GLfloat (*dst)[2] = (GLfloat (*)[2]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i][0] = (rowA[j][0] + rowA[k][0] +
-                         rowB[j][0] + rowB[k][0]) * 0.25F;
-            dst[i][1] = (rowA[j][1] + rowA[k][1] +
-                         rowB[j][1] + rowB[k][1]) * 0.25F;
-         }
+   }
+
+   else if (datatype == GL_UNSIGNED_SHORT_5_6_5 && comps == 3) {
+      GLuint i, j, k;
+      const GLushort *rowA = (const GLushort *) srcRowA;
+      const GLushort *rowB = (const GLushort *) srcRowB;
+      GLushort *dst = (GLushort *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         const GLint rowAr0 = rowA[j] & 0x1f;
+         const GLint rowAr1 = rowA[k] & 0x1f;
+         const GLint rowBr0 = rowB[j] & 0x1f;
+         const GLint rowBr1 = rowB[k] & 0x1f;
+         const GLint rowAg0 = (rowA[j] >> 5) & 0x3f;
+         const GLint rowAg1 = (rowA[k] >> 5) & 0x3f;
+         const GLint rowBg0 = (rowB[j] >> 5) & 0x3f;
+         const GLint rowBg1 = (rowB[k] >> 5) & 0x3f;
+         const GLint rowAb0 = (rowA[j] >> 11) & 0x1f;
+         const GLint rowAb1 = (rowA[k] >> 11) & 0x1f;
+         const GLint rowBb0 = (rowB[j] >> 11) & 0x1f;
+         const GLint rowBb1 = (rowB[k] >> 11) & 0x1f;
+         const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
+         const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
+         const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
+         dst[i] = (blue << 11) | (green << 5) | red;
       }
-      return;
-   case MESA_FORMAT_LUMINANCE_ALPHA_FLOAT16:
-      {
-         GLuint i, j, k, comp;
-         const GLhalfARB (*rowA)[2] = (const GLhalfARB (*)[2]) srcRowA;
-         const GLhalfARB (*rowB)[2] = (const GLhalfARB (*)[2]) srcRowB;
-         GLhalfARB (*dst)[2] = (GLhalfARB (*)[2]) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            for (comp = 0; comp < 2; comp++) {
-               GLfloat aj, ak, bj, bk;
-               aj = _mesa_half_to_float(rowA[j][comp]);
-               ak = _mesa_half_to_float(rowA[k][comp]);
-               bj = _mesa_half_to_float(rowB[j][comp]);
-               bk = _mesa_half_to_float(rowB[k][comp]);
-               dst[i][comp] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
-            }
-         }
+   }
+   else if (datatype == GL_UNSIGNED_SHORT_4_4_4_4 && comps == 4) {
+      GLuint i, j, k;
+      const GLushort *rowA = (const GLushort *) srcRowA;
+      const GLushort *rowB = (const GLushort *) srcRowB;
+      GLushort *dst = (GLushort *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         const GLint rowAr0 = rowA[j] & 0xf;
+         const GLint rowAr1 = rowA[k] & 0xf;
+         const GLint rowBr0 = rowB[j] & 0xf;
+         const GLint rowBr1 = rowB[k] & 0xf;
+         const GLint rowAg0 = (rowA[j] >> 4) & 0xf;
+         const GLint rowAg1 = (rowA[k] >> 4) & 0xf;
+         const GLint rowBg0 = (rowB[j] >> 4) & 0xf;
+         const GLint rowBg1 = (rowB[k] >> 4) & 0xf;
+         const GLint rowAb0 = (rowA[j] >> 8) & 0xf;
+         const GLint rowAb1 = (rowA[k] >> 8) & 0xf;
+         const GLint rowBb0 = (rowB[j] >> 8) & 0xf;
+         const GLint rowBb1 = (rowB[k] >> 8) & 0xf;
+         const GLint rowAa0 = (rowA[j] >> 12) & 0xf;
+         const GLint rowAa1 = (rowA[k] >> 12) & 0xf;
+         const GLint rowBa0 = (rowB[j] >> 12) & 0xf;
+         const GLint rowBa1 = (rowB[k] >> 12) & 0xf;
+         const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
+         const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
+         const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
+         const GLint alpha = (rowAa0 + rowAa1 + rowBa0 + rowBa1) >> 2;
+         dst[i] = (alpha << 12) | (blue << 8) | (green << 4) | red;
       }
-      return;
-   case MESA_FORMAT_ALPHA_FLOAT32:
-   case MESA_FORMAT_LUMINANCE_FLOAT32:
-   case MESA_FORMAT_INTENSITY_FLOAT32:
-      {
-         GLuint i, j, k;
-         const GLfloat *rowA = (const GLfloat *) srcRowA;
-         const GLfloat *rowB = (const GLfloat *) srcRowB;
-         GLfloat *dst = (GLfloat *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            dst[i] = (rowA[j] + rowA[k] + rowB[j] + rowB[k]) * 0.25F;
-         }
+   }
+   else if (datatype == GL_UNSIGNED_SHORT_1_5_5_5_REV && comps == 4) {
+      GLuint i, j, k;
+      const GLushort *rowA = (const GLushort *) srcRowA;
+      const GLushort *rowB = (const GLushort *) srcRowB;
+      GLushort *dst = (GLushort *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         const GLint rowAr0 = rowA[j] & 0x1f;
+         const GLint rowAr1 = rowA[k] & 0x1f;
+         const GLint rowBr0 = rowB[j] & 0x1f;
+         const GLint rowBr1 = rowB[k] & 0xf;
+         const GLint rowAg0 = (rowA[j] >> 5) & 0x1f;
+         const GLint rowAg1 = (rowA[k] >> 5) & 0x1f;
+         const GLint rowBg0 = (rowB[j] >> 5) & 0x1f;
+         const GLint rowBg1 = (rowB[k] >> 5) & 0x1f;
+         const GLint rowAb0 = (rowA[j] >> 10) & 0x1f;
+         const GLint rowAb1 = (rowA[k] >> 10) & 0x1f;
+         const GLint rowBb0 = (rowB[j] >> 10) & 0x1f;
+         const GLint rowBb1 = (rowB[k] >> 10) & 0x1f;
+         const GLint rowAa0 = (rowA[j] >> 15) & 0x1;
+         const GLint rowAa1 = (rowA[k] >> 15) & 0x1;
+         const GLint rowBa0 = (rowB[j] >> 15) & 0x1;
+         const GLint rowBa1 = (rowB[k] >> 15) & 0x1;
+         const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
+         const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
+         const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
+         const GLint alpha = (rowAa0 + rowAa1 + rowBa0 + rowBa1) >> 2;
+         dst[i] = (alpha << 15) | (blue << 10) | (green << 5) | red;
       }
-      return;
-   case MESA_FORMAT_ALPHA_FLOAT16:
-   case MESA_FORMAT_LUMINANCE_FLOAT16:
-   case MESA_FORMAT_INTENSITY_FLOAT16:
-      {
-         GLuint i, j, k;
-         const GLhalfARB *rowA = (const GLhalfARB *) srcRowA;
-         const GLhalfARB *rowB = (const GLhalfARB *) srcRowB;
-         GLhalfARB *dst = (GLhalfARB *) dstRow;
-         for (i = j = 0, k = k0; i < (GLuint) dstWidth;
-              i++, j += colStride, k += colStride) {
-            GLfloat aj, ak, bj, bk;
-            aj = _mesa_half_to_float(rowA[j]);
-            ak = _mesa_half_to_float(rowA[k]);
-            bj = _mesa_half_to_float(rowB[j]);
-            bk = _mesa_half_to_float(rowB[k]);
-            dst[i] = _mesa_float_to_half((aj + ak + bj + bk) * 0.25F);
-         }
+   }
+   else if (datatype == GL_UNSIGNED_BYTE_3_3_2 && comps == 3) {
+      GLuint i, j, k;
+      const GLubyte *rowA = (const GLubyte *) srcRowA;
+      const GLubyte *rowB = (const GLubyte *) srcRowB;
+      GLubyte *dst = (GLubyte *) dstRow;
+      for (i = j = 0, k = k0; i < (GLuint) dstWidth;
+           i++, j += colStride, k += colStride) {
+         const GLint rowAr0 = rowA[j] & 0x3;
+         const GLint rowAr1 = rowA[k] & 0x3;
+         const GLint rowBr0 = rowB[j] & 0x3;
+         const GLint rowBr1 = rowB[k] & 0x3;
+         const GLint rowAg0 = (rowA[j] >> 2) & 0x7;
+         const GLint rowAg1 = (rowA[k] >> 2) & 0x7;
+         const GLint rowBg0 = (rowB[j] >> 2) & 0x7;
+         const GLint rowBg1 = (rowB[k] >> 2) & 0x7;
+         const GLint rowAb0 = (rowA[j] >> 5) & 0x7;
+         const GLint rowAb1 = (rowA[k] >> 5) & 0x7;
+         const GLint rowBb0 = (rowB[j] >> 5) & 0x7;
+         const GLint rowBb1 = (rowB[k] >> 5) & 0x7;
+         const GLint red = (rowAr0 + rowAr1 + rowBr0 + rowBr1) >> 2;
+         const GLint green = (rowAg0 + rowAg1 + rowBg0 + rowBg1) >> 2;
+         const GLint blue = (rowAb0 + rowAb1 + rowBb0 + rowBb1) >> 2;
+         dst[i] = (blue << 5) | (green << 2) | red;
       }
-      return;
-
-   default:
+   }
+   else {
       _mesa_problem(NULL, "bad format in do_row()");
    }
 }
@@ -504,11 +419,11 @@ do_row(const struct gl_texture_format *format, GLint srcWidth,
  */
 
 static void
-make_1d_mipmap(const struct gl_texture_format *format, GLint border,
+make_1d_mipmap(GLenum datatype, GLuint comps, GLint border,
                GLint srcWidth, const GLubyte *srcPtr,
                GLint dstWidth, GLubyte *dstPtr)
 {
-   const GLint bpt = format->TexelBytes;
+   const GLint bpt = bytes_per_pixel(datatype, comps);
    const GLubyte *src;
    GLubyte *dst;
 
@@ -517,7 +432,7 @@ make_1d_mipmap(const struct gl_texture_format *format, GLint border,
    dst = dstPtr + border * bpt;
 
    /* we just duplicate the input row, kind of hack, saves code */
-   do_row(format, srcWidth - 2 * border, src, src,
+   do_row(datatype, comps, srcWidth - 2 * border, src, src,
           dstWidth - 2 * border, dst);
 
    if (border) {
@@ -531,23 +446,30 @@ make_1d_mipmap(const struct gl_texture_format *format, GLint border,
 }
 
 
+/**
+ * Strides are in bytes.  If zero, it'll be computed as width * bpp.
+ */
 static void
-make_2d_mipmap(const struct gl_texture_format *format, GLint border,
+make_2d_mipmap(GLenum datatype, GLuint comps, GLint border,
                GLint srcWidth, GLint srcHeight,
-	       const GLubyte *srcPtr, GLint srcRowStride,
+               GLint srcRowStride, const GLubyte *srcPtr,
                GLint dstWidth, GLint dstHeight,
-	       GLubyte *dstPtr, GLint dstRowStride)
+               GLint dstRowStride, GLubyte *dstPtr)
 {
-   const GLint bpt = format->TexelBytes;
+   const GLint bpt = bytes_per_pixel(datatype, comps);
    const GLint srcWidthNB = srcWidth - 2 * border;  /* sizes w/out border */
    const GLint dstWidthNB = dstWidth - 2 * border;
    const GLint dstHeightNB = dstHeight - 2 * border;
-   const GLint srcRowBytes = bpt * srcRowStride;
-   const GLint dstRowBytes = bpt * dstRowStride;
    const GLubyte *srcA, *srcB;
    GLubyte *dst;
    GLint row;
 
+   if (!srcRowStride)
+      srcRowStride = bpt * srcWidth;
+
+   if (!dstRowStride)
+      dstRowStride = bpt * dstWidth;
+
    /* Compute src and dst pointers, skipping any border */
    srcA = srcPtr + border * ((srcWidth + 1) * bpt);
    if (srcHeight > 1) 
@@ -557,7 +479,7 @@ make_2d_mipmap(const struct gl_texture_format *format, GLint border,
    dst = dstPtr + border * ((dstWidth + 1) * bpt);
 
    for (row = 0; row < dstHeightNB; row++) {
-      do_row(format, srcWidthNB, srcA, srcB,
+      do_row(datatype, comps, srcWidthNB, srcA, srcB,
              dstWidthNB, dst);
       srcA += 2 * srcRowBytes;
       srcB += 2 * srcRowBytes;
@@ -579,12 +501,12 @@ make_2d_mipmap(const struct gl_texture_format *format, GLint border,
       MEMCPY(dstPtr + (dstWidth * dstHeight - 1) * bpt,
              srcPtr + (srcWidth * srcHeight - 1) * bpt, bpt);
       /* lower border */
-      do_row(format, srcWidthNB,
+      do_row(datatype, comps, srcWidthNB,
              srcPtr + bpt,
              srcPtr + bpt,
              dstWidthNB, dstPtr + bpt);
       /* upper border */
-      do_row(format, srcWidthNB,
+      do_row(datatype, comps, srcWidthNB,
              srcPtr + (srcWidth * (srcHeight - 1) + 1) * bpt,
              srcPtr + (srcWidth * (srcHeight - 1) + 1) * bpt,
              dstWidthNB,
@@ -602,11 +524,11 @@ make_2d_mipmap(const struct gl_texture_format *format, GLint border,
       else {
          /* average two src pixels each dest pixel */
          for (row = 0; row < dstHeightNB; row += 2) {
-            do_row(format, 1,
+            do_row(datatype, comps, 1,
                    srcPtr + (srcWidth * (row * 2 + 1)) * bpt,
                    srcPtr + (srcWidth * (row * 2 + 2)) * bpt,
                    1, dstPtr + (dstWidth * row + 1) * bpt);
-            do_row(format, 1,
+            do_row(datatype, comps, 1,
                    srcPtr + (srcWidth * (row * 2 + 1) + srcWidth - 1) * bpt,
                    srcPtr + (srcWidth * (row * 2 + 2) + srcWidth - 1) * bpt,
                    1, dstPtr + (dstWidth * row + 1 + dstWidth - 1) * bpt);
@@ -617,13 +539,15 @@ make_2d_mipmap(const struct gl_texture_format *format, GLint border,
 
 
 static void
-make_3d_mipmap(const struct gl_texture_format *format, GLint border,
+make_3d_mipmap(GLenum datatype, GLuint comps, GLint border,
                GLint srcWidth, GLint srcHeight, GLint srcDepth,
-               const GLubyte *srcPtr, GLint srcRowStride,
+               GLint srcRowStride,
+               const GLubyte *srcPtr,
                GLint dstWidth, GLint dstHeight, GLint dstDepth,
-               GLubyte *dstPtr, GLint dstRowStride)
+               GLint dstRowStride,
+               GLubyte *dstPtr)
 {
-   const GLint bpt = format->TexelBytes;
+   const GLint bpt = bytes_per_pixel(datatype, comps);
    const GLint srcWidthNB = srcWidth - 2 * border;  /* sizes w/out border */
    const GLint srcDepthNB = srcDepth - 2 * border;
    const GLint dstWidthNB = dstWidth - 2 * border;
@@ -632,7 +556,6 @@ make_3d_mipmap(const struct gl_texture_format *format, GLint border,
    GLvoid *tmpRowA, *tmpRowB;
    GLint img, row;
    GLint bytesPerSrcImage, bytesPerDstImage;
-   GLint bytesPerSrcRow, bytesPerDstRow;
    GLint srcImageOffset, srcRowOffset;
 
    (void) srcDepthNB; /* silence warnings */
@@ -650,8 +573,10 @@ make_3d_mipmap(const struct gl_texture_format *format, GLint border,
    bytesPerSrcImage = srcWidth * srcHeight * bpt;
    bytesPerDstImage = dstWidth * dstHeight * bpt;
 
-   bytesPerSrcRow = srcWidth * bpt;
-   bytesPerDstRow = dstWidth * bpt;
+   if (!srcRowStride)
+      srcRowStride = srcWidth * bpt;
+   if (!dstRowStride)
+      dstRowStride = dstWidth * bpt;
 
    /* Offset between adjacent src images to be averaged together */
    srcImageOffset = (srcDepth == dstDepth) ? 0 : bytesPerSrcImage;
@@ -675,13 +600,13 @@ make_3d_mipmap(const struct gl_texture_format *format, GLint border,
    for (img = 0; img < dstDepthNB; img++) {
       /* first source image pointer, skipping border */
       const GLubyte *imgSrcA = srcPtr
-         + (bytesPerSrcImage + bytesPerSrcRow + border) * bpt * border
+         + (bytesPerSrcImage + srcRowStride + border) * bpt * border
          + img * (bytesPerSrcImage + srcImageOffset);
       /* second source image pointer, skipping border */
       const GLubyte *imgSrcB = imgSrcA + srcImageOffset;
       /* address of the dest image, skipping border */
       GLubyte *imgDst = dstPtr
-         + (bytesPerDstImage + bytesPerDstRow + border) * bpt * border
+         + (bytesPerDstImage + dstRowStride + border) * bpt * border
          + img * bytesPerDstImage;
 
       /* setup the four source row pointers and the dest row pointer */
@@ -693,20 +618,20 @@ make_3d_mipmap(const struct gl_texture_format *format, GLint border,
 
       for (row = 0; row < dstHeightNB; row++) {
          /* Average together two rows from first src image */
-         do_row(format, srcWidthNB, srcImgARowA, srcImgARowB,
+         do_row(datatype, comps, srcWidthNB, srcImgARowA, srcImgARowB,
                 srcWidthNB, tmpRowA);
          /* Average together two rows from second src image */
-         do_row(format, srcWidthNB, srcImgBRowA, srcImgBRowB,
+         do_row(datatype, comps, srcWidthNB, srcImgBRowA, srcImgBRowB,
                 srcWidthNB, tmpRowB);
          /* Average together the temp rows to make the final row */
-         do_row(format, srcWidthNB, tmpRowA, tmpRowB,
+         do_row(datatype, comps, srcWidthNB, tmpRowA, tmpRowB,
                 dstWidthNB, dstImgRow);
          /* advance to next rows */
-         srcImgARowA += bytesPerSrcRow + srcRowOffset;
-         srcImgARowB += bytesPerSrcRow + srcRowOffset;
-         srcImgBRowA += bytesPerSrcRow + srcRowOffset;
-         srcImgBRowB += bytesPerSrcRow + srcRowOffset;
-         dstImgRow += bytesPerDstRow;
+         srcImgARowA += srcRowStride + srcRowOffset;
+         srcImgARowB += srcRowStride + srcRowOffset;
+         srcImgBRowA += srcRowStride + srcRowOffset;
+         srcImgBRowB += srcRowStride + srcRowOffset;
+         dstImgRow += dstRowStride;
       }
    }
 
@@ -716,13 +641,15 @@ make_3d_mipmap(const struct gl_texture_format *format, GLint border,
    /* Luckily we can leverage the make_2d_mipmap() function here! */
    if (border > 0) {
       /* do front border image */
-      make_2d_mipmap(format, 1, srcWidth, srcHeight, srcPtr, srcRowStride,
-                     dstWidth, dstHeight, dstPtr, dstRowStride);
+      make_2d_mipmap(datatype, comps, 1, srcWidth, srcHeight, 0, srcPtr,
+                     dstWidth, dstHeight, 0, dstPtr);
       /* do back border image */
-      make_2d_mipmap(format, 1, srcWidth, srcHeight,
-                     srcPtr + bytesPerSrcImage * (srcDepth - 1), srcRowStride,
+      make_2d_mipmap(datatype, comps, 1, srcWidth, srcHeight,
+                     0, 
+                     srcPtr + bytesPerSrcImage * (srcDepth - 1),
                      dstWidth, dstHeight,
-                     dstPtr + bytesPerDstImage * (dstDepth - 1), dstRowStride);
+                     0,
+                     dstPtr + bytesPerDstImage * (dstDepth - 1));
       /* do four remaining border edges that span the image slices */
       if (srcDepth == dstDepth) {
          /* just copy border pixels from src to dst */
@@ -737,9 +664,9 @@ make_3d_mipmap(const struct gl_texture_format *format, GLint border,
 
             /* do border along [img][row=dstHeight-1][col=0] */
             src = srcPtr + (img * 2 + 1) * bytesPerSrcImage
-                         + (srcHeight - 1) * bytesPerSrcRow;
+                         + (srcHeight - 1) * srcRowStride;
             dst = dstPtr + (img + 1) * bytesPerDstImage
-                         + (dstHeight - 1) * bytesPerDstRow;
+                         + (dstHeight - 1) * dstRowStride;
             MEMCPY(dst, src, bpt);
 
             /* do border along [img][row=0][col=dstWidth-1] */
@@ -767,28 +694,28 @@ make_3d_mipmap(const struct gl_texture_format *format, GLint border,
             /* do border along [img][row=0][col=0] */
             src = srcPtr + (img * 2 + 1) * bytesPerSrcImage;
             dst = dstPtr + (img + 1) * bytesPerDstImage;
-            do_row(format, 1, src, src + srcImageOffset, 1, dst);
+            do_row(datatype, comps, 1, src, src + srcImageOffset, 1, dst);
 
             /* do border along [img][row=dstHeight-1][col=0] */
             src = srcPtr + (img * 2 + 1) * bytesPerSrcImage
-                         + (srcHeight - 1) * bytesPerSrcRow;
+                         + (srcHeight - 1) * srcRowStride;
             dst = dstPtr + (img + 1) * bytesPerDstImage
-                         + (dstHeight - 1) * bytesPerDstRow;
-            do_row(format, 1, src, src + srcImageOffset, 1, dst);
+                         + (dstHeight - 1) * dstRowStride;
+            do_row(datatype, comps, 1, src, src + srcImageOffset, 1, dst);
 
             /* do border along [img][row=0][col=dstWidth-1] */
             src = srcPtr + (img * 2 + 1) * bytesPerSrcImage
                          + (srcWidth - 1) * bpt;
             dst = dstPtr + (img + 1) * bytesPerDstImage
                          + (dstWidth - 1) * bpt;
-            do_row(format, 1, src, src + srcImageOffset, 1, dst);
+            do_row(datatype, comps, 1, src, src + srcImageOffset, 1, dst);
 
             /* do border along [img][row=dstHeight-1][col=dstWidth-1] */
             src = srcPtr + (img * 2 + 1) * bytesPerSrcImage
                          + (bytesPerSrcImage - bpt);
             dst = dstPtr + (img + 1) * bytesPerDstImage
                          + (bytesPerDstImage - bpt);
-            do_row(format, 1, src, src + srcImageOffset, 1, dst);
+            do_row(datatype, comps, 1, src, src + srcImageOffset, 1, dst);
          }
       }
    }
@@ -796,12 +723,11 @@ make_3d_mipmap(const struct gl_texture_format *format, GLint border,
 
 
 static void
-make_1d_stack_mipmap(const struct gl_texture_format *format, GLint border,
-                     GLint srcWidth, const GLubyte *srcPtr, GLuint srcRowStride,
-                     GLint dstWidth, GLint dstHeight,
-		     GLubyte *dstPtr, GLuint dstRowStride )
+make_1d_stack_mipmap(GLenum datatype, GLuint comps, GLint border,
+                     GLint srcWidth, const GLubyte *srcPtr,
+                     GLint dstWidth, GLint dstHeight, GLubyte *dstPtr)
 {
-   const GLint bpt = format->TexelBytes;
+   const GLint bpt = bytes_per_pixel(datatype, comps);
    const GLint srcWidthNB = srcWidth - 2 * border;  /* sizes w/out border */
    const GLint dstWidthNB = dstWidth - 2 * border;
    const GLint dstHeightNB = dstHeight - 2 * border;
@@ -816,7 +742,7 @@ make_1d_stack_mipmap(const struct gl_texture_format *format, GLint border,
    dst = dstPtr + border * ((dstWidth + 1) * bpt);
 
    for (row = 0; row < dstHeightNB; row++) {
-      do_row(format, srcWidthNB, src, src,
+      do_row(datatype, comps, srcWidthNB, src, src,
              dstWidthNB, dst);
       src += srcRowBytes;
       dst += dstRowBytes;
@@ -839,24 +765,30 @@ make_1d_stack_mipmap(const struct gl_texture_format *format, GLint border,
  * and \c make_2d_mipmap.
  */
 static void
-make_2d_stack_mipmap(const struct gl_texture_format *format, GLint border,
+make_2d_stack_mipmap(GLenum datatype, GLuint comps, GLint border,
                      GLint srcWidth, GLint srcHeight,
-		     const GLubyte *srcPtr, GLint srcRowStride,
+                     GLint srcRowStride,
+                     const GLubyte *srcPtr,
                      GLint dstWidth, GLint dstHeight, GLint dstDepth,
-                     GLubyte *dstPtr, GLint dstRowStride)
+                     GLint dstRowStride,
+                     GLubyte *dstPtr)
 {
-   const GLint bpt = format->TexelBytes;
+   const GLint bpt = bytes_per_pixel(datatype, comps);
    const GLint srcWidthNB = srcWidth - 2 * border;  /* sizes w/out border */
    const GLint dstWidthNB = dstWidth - 2 * border;
    const GLint dstHeightNB = dstHeight - 2 * border;
    const GLint dstDepthNB = dstDepth - 2 * border;
-   const GLint srcRowBytes = bpt * srcRowStride;
-   const GLint dstRowBytes = bpt * dstRowStride;
    const GLubyte *srcA, *srcB;
    GLubyte *dst;
    GLint layer;
    GLint row;
 
+   if (!srcRowStride)
+      srcRowStride = bpt * srcWidth;
+
+   if (!dstRowStride)
+      dstRowStride = bpt * dstWidth;
+
    /* Compute src and dst pointers, skipping any border */
    srcA = srcPtr + border * ((srcWidth + 1) * bpt);
    if (srcHeight > 1) 
@@ -867,7 +799,7 @@ make_2d_stack_mipmap(const struct gl_texture_format *format, GLint border,
 
    for (layer = 0; layer < dstDepthNB; layer++) {
       for (row = 0; row < dstHeightNB; row++) {
-         do_row(format, srcWidthNB, srcA, srcB,
+         do_row(datatype, comps, srcWidthNB, srcA, srcB,
                 dstWidthNB, dst);
          srcA += 2 * srcRowBytes;
          srcB += 2 * srcRowBytes;
@@ -889,12 +821,12 @@ make_2d_stack_mipmap(const struct gl_texture_format *format, GLint border,
          MEMCPY(dstPtr + (dstWidth * dstHeight - 1) * bpt,
                 srcPtr + (srcWidth * srcHeight - 1) * bpt, bpt);
          /* lower border */
-         do_row(format, srcWidthNB,
+         do_row(datatype, comps, srcWidthNB,
                 srcPtr + bpt,
                 srcPtr + bpt,
                 dstWidthNB, dstPtr + bpt);
          /* upper border */
-         do_row(format, srcWidthNB,
+         do_row(datatype, comps, srcWidthNB,
                 srcPtr + (srcWidth * (srcHeight - 1) + 1) * bpt,
                 srcPtr + (srcWidth * (srcHeight - 1) + 1) * bpt,
                 dstWidthNB,
@@ -912,11 +844,11 @@ make_2d_stack_mipmap(const struct gl_texture_format *format, GLint border,
          else {
             /* average two src pixels each dest pixel */
             for (row = 0; row < dstHeightNB; row += 2) {
-               do_row(format, 1,
+               do_row(datatype, comps, 1,
                       srcPtr + (srcWidth * (row * 2 + 1)) * bpt,
                       srcPtr + (srcWidth * (row * 2 + 2)) * bpt,
                       1, dstPtr + (dstWidth * row + 1) * bpt);
-               do_row(format, 1,
+               do_row(datatype, comps, 1,
                       srcPtr + (srcWidth * (row * 2 + 1) + srcWidth - 1) * bpt,
                       srcPtr + (srcWidth * (row * 2 + 2) + srcWidth - 1) * bpt,
                       1, dstPtr + (dstWidth * row + 1 + dstWidth - 1) * bpt);
@@ -928,6 +860,106 @@ make_2d_stack_mipmap(const struct gl_texture_format *format, GLint border,
 
 
 /**
+ * Down-sample a texture image to produce the next lower mipmap level.
+ */
+void
+_mesa_generate_mipmap_level(GLenum target,
+                            GLenum datatype, GLuint comps,
+                            GLint border,
+                            GLint srcWidth, GLint srcHeight, GLint srcDepth,
+                            GLint srcRowStride,
+                            const GLubyte *srcData,
+                            GLint dstWidth, GLint dstHeight, GLint dstDepth,
+                            GLint dstRowStride,
+                            GLubyte *dstData)
+{
+   switch (target) {
+   case GL_TEXTURE_1D:
+      make_1d_mipmap(datatype, comps, border,
+                     srcWidth, srcData,
+                     dstWidth, dstData);
+      break;
+   case GL_TEXTURE_2D:
+   case GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB:
+   case GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB:
+   case GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB:
+   case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB:
+   case GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB:
+   case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB:
+      make_2d_mipmap(datatype, comps, border,
+                     srcWidth, srcHeight, srcRowStride, srcData,
+                     dstWidth, dstHeight, dstRowStride, dstData);
+      break;
+   case GL_TEXTURE_3D:
+      make_3d_mipmap(datatype, comps, border,
+                     srcWidth, srcHeight, srcDepth, srcRowStride, srcData,
+                     dstWidth, dstHeight, dstDepth, dstRowStride, dstData);
+      break;
+   case GL_TEXTURE_1D_ARRAY_EXT:
+      make_1d_stack_mipmap(datatype, comps, border,
+                           srcWidth, srcData,
+                           dstWidth, dstHeight, dstData);
+      break;
+   case GL_TEXTURE_2D_ARRAY_EXT:
+      make_2d_stack_mipmap(datatype, comps, border,
+                           srcWidth, srcHeight, srcRowStride, srcData,
+                           dstWidth, dstHeight, dstDepth, dstRowStride, dstData);
+      break;
+   case GL_TEXTURE_RECTANGLE_NV:
+      /* no mipmaps, do nothing */
+      break;
+   default:
+      _mesa_problem(NULL, "bad target in _mesa_generate_mipmap_level");
+   }
+}
+
+
+/**
+ * compute next (level+1) image size
+ * \return GL_FALSE if no smaller size can be generated (eg. src is 1x1x1 size)
+ */
+static GLboolean
+next_mipmap_level_size(GLenum target, GLint border,
+                       GLint srcWidth, GLint srcHeight, GLint srcDepth,
+                       GLint *dstWidth, GLint *dstHeight, GLint *dstDepth)
+{
+   if (srcWidth - 2 * border > 1) {
+      *dstWidth = (srcWidth - 2 * border) / 2 + 2 * border;
+   }
+   else {
+      *dstWidth = srcWidth; /* can't go smaller */
+   }
+
+   if ((srcHeight - 2 * border > 1) && 
+       (target != GL_TEXTURE_1D_ARRAY_EXT)) {
+      *dstHeight = (srcHeight - 2 * border) / 2 + 2 * border;
+   }
+   else {
+      *dstHeight = srcHeight; /* can't go smaller */
+   }
+
+   if ((srcDepth - 2 * border > 1) &&
+       (target != GL_TEXTURE_2D_ARRAY_EXT)) {
+      *dstDepth = (srcDepth - 2 * border) / 2 + 2 * border;
+   }
+   else {
+      *dstDepth = srcDepth; /* can't go smaller */
+   }
+
+   if (*dstWidth == srcWidth &&
+       *dstHeight == srcHeight &&
+       *dstDepth == srcDepth) {
+      return GL_FALSE;
+   }
+   else {
+      return GL_TRUE;
+   }
+}
+
+
+
+
+/**
  * For GL_SGIX_generate_mipmap:
  * Generate a complete set of mipmaps from texObj's base-level image.
  * Stop at texObj's MaxLevel or when we get to the 1x1 texture.
@@ -941,6 +973,8 @@ _mesa_generate_mipmap(GLcontext *ctx, GLenum target,
    const GLubyte *srcData = NULL;
    GLubyte *dstData = NULL;
    GLint level, maxLevels;
+   GLenum datatype;
+   GLuint comps;
 
    ASSERT(texObj);
    /* XXX choose cube map face here??? */
@@ -1004,6 +1038,8 @@ _mesa_generate_mipmap(GLcontext *ctx, GLenum target,
       convertFormat = srcImage->TexFormat;
    }
 
+   _mesa_format_to_type_and_comps(convertFormat, &datatype, &comps);
+
    for (level = texObj->BaseLevel; level < texObj->MaxLevel
            && level < maxLevels - 1; level++) {
       /* generate image[level+1] from image[level] */
@@ -1012,6 +1048,7 @@ _mesa_generate_mipmap(GLcontext *ctx, GLenum target,
       GLint srcWidth, srcHeight, srcDepth;
       GLint dstWidth, dstHeight, dstDepth;
       GLint border, bytesPerTexel;
+      GLboolean nextLevel;
 
       /* get src image parameters */
       srcImage = _mesa_select_tex_image(ctx, texObj, target, level);
@@ -1021,31 +1058,10 @@ _mesa_generate_mipmap(GLcontext *ctx, GLenum target,
       srcDepth = srcImage->Depth;
       border = srcImage->Border;
 
-      /* compute next (level+1) image size */
-      if (srcWidth - 2 * border > 1) {
-         dstWidth = (srcWidth - 2 * border) / 2 + 2 * border;
-      }
-      else {
-         dstWidth = srcWidth; /* can't go smaller */
-      }
-      if ((srcHeight - 2 * border > 1) && 
-          (texObj->Target != GL_TEXTURE_1D_ARRAY_EXT)) {
-         dstHeight = (srcHeight - 2 * border) / 2 + 2 * border;
-      }
-      else {
-         dstHeight = srcHeight; /* can't go smaller */
-      }
-      if ((srcDepth - 2 * border > 1) &&
-               (texObj->Target != GL_TEXTURE_2D_ARRAY_EXT)) {
-         dstDepth = (srcDepth - 2 * border) / 2 + 2 * border;
-      }
-      else {
-         dstDepth = srcDepth; /* can't go smaller */
-      }
-
-      if (dstWidth == srcWidth &&
-          dstHeight == srcHeight &&
-          dstDepth == srcDepth) {
+      nextLevel = next_mipmap_level_size(target, border,
+                                         srcWidth, srcHeight, srcDepth,
+                                         &dstWidth, &dstHeight, &dstDepth);
+      if (!nextLevel) {
          /* all done */
          if (srcImage->IsCompressed) {
             _mesa_free((void *) srcData);
@@ -1115,53 +1131,10 @@ _mesa_generate_mipmap(GLcontext *ctx, GLenum target,
          dstData = (GLubyte *) dstImage->Data;
       }
 
-      /*
-       * We use simple 2x2 averaging to compute the next mipmap level.
-       */
-      switch (target) {
-         case GL_TEXTURE_1D:
-            make_1d_mipmap(convertFormat, border,
-                           srcWidth, srcData,
-                           dstWidth, dstData);
-            break;
-         case GL_TEXTURE_2D:
-         case GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB:
-         case GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB:
-         case GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB:
-         case GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB:
-         case GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB:
-         case GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB:
-            make_2d_mipmap(convertFormat, border,
-                           srcWidth, srcHeight, srcData, srcImage->RowStride,
-                           dstWidth, dstHeight, dstData, dstImage->RowStride);
-            break;
-         case GL_TEXTURE_3D:
-            make_3d_mipmap(convertFormat, border,
-                           srcWidth, srcHeight, srcDepth,
-			   srcData, srcImage->RowStride,
-                           dstWidth, dstHeight, dstDepth,
-			   dstData, dstImage->RowStride);
-            break;
-         case GL_TEXTURE_1D_ARRAY_EXT:
-            make_1d_stack_mipmap(convertFormat, border,
-                                 srcWidth, srcData, srcImage->RowStride,
-                                 dstWidth, dstHeight,
-				 dstData, dstImage->RowStride);
-            break;
-         case GL_TEXTURE_2D_ARRAY_EXT:
-            make_2d_stack_mipmap(convertFormat, border,
-                                 srcWidth, srcHeight,
-				 srcData, srcImage->RowStride,
-                                 dstWidth, dstHeight,
-				 dstDepth, dstData, dstImage->RowStride);
-            break;
-         case GL_TEXTURE_RECTANGLE_NV:
-            /* no mipmaps, do nothing */
-            break;
-         default:
-            _mesa_problem(ctx, "bad dimensions in _mesa_generate_mipmaps");
-            return;
-      }
+      /* Note, 0 indicates default row strides */
+      _mesa_generate_mipmap_level(target, datatype, comps, border,
+                                  srcWidth, srcHeight, srcDepth, 0, srcData,
+                                  dstWidth, dstHeight, dstDepth, 0, dstData);
 
       if (dstImage->IsCompressed) {
          GLubyte *temp;