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authorBrian Paul <brian.paul@tungstengraphics.com>2001-05-15 16:18:13 +0000
committerBrian Paul <brian.paul@tungstengraphics.com>2001-05-15 16:18:13 +0000
commit80532da3bf2a83448c6f38c34dbaf32898acea2d (patch)
treeeb6e8db2f6524d47f3ebc95d26f4f822d911cc29 /src/mesa
parentd57bcbed46207cb1810902e1435faf504047cd58 (diff)
minor clean-ups and more comments
Diffstat (limited to 'src/mesa')
-rw-r--r--src/mesa/swrast/s_aatriangle.c8
-rw-r--r--src/mesa/swrast/s_aatritemp.h41
2 files changed, 38 insertions, 11 deletions
diff --git a/src/mesa/swrast/s_aatriangle.c b/src/mesa/swrast/s_aatriangle.c
index 9a9eb877f1..d81250292d 100644
--- a/src/mesa/swrast/s_aatriangle.c
+++ b/src/mesa/swrast/s_aatriangle.c
@@ -1,4 +1,4 @@
-/* $Id: s_aatriangle.c,v 1.14 2001/05/10 17:41:41 brianp Exp $ */
+/* $Id: s_aatriangle.c,v 1.15 2001/05/15 16:18:13 brianp Exp $ */
/*
* Mesa 3-D graphics library
@@ -309,6 +309,7 @@ rgba_aa_tri(GLcontext *ctx,
const SWvertex *v2)
{
#define DO_Z
+#define DO_FOG
#define DO_RGBA
#include "s_aatritemp.h"
}
@@ -321,6 +322,7 @@ index_aa_tri(GLcontext *ctx,
const SWvertex *v2)
{
#define DO_Z
+#define DO_FOG
#define DO_INDEX
#include "s_aatritemp.h"
}
@@ -355,6 +357,7 @@ tex_aa_tri(GLcontext *ctx,
const SWvertex *v2)
{
#define DO_Z
+#define DO_FOG
#define DO_RGBA
#define DO_TEX
#include "s_aatritemp.h"
@@ -368,6 +371,7 @@ spec_tex_aa_tri(GLcontext *ctx,
const SWvertex *v2)
{
#define DO_Z
+#define DO_FOG
#define DO_RGBA
#define DO_TEX
#define DO_SPEC
@@ -382,6 +386,7 @@ multitex_aa_tri(GLcontext *ctx,
const SWvertex *v2)
{
#define DO_Z
+#define DO_FOG
#define DO_RGBA
#define DO_MULTITEX
#include "s_aatritemp.h"
@@ -394,6 +399,7 @@ spec_multitex_aa_tri(GLcontext *ctx,
const SWvertex *v2)
{
#define DO_Z
+#define DO_FOG
#define DO_RGBA
#define DO_MULTITEX
#define DO_SPEC
diff --git a/src/mesa/swrast/s_aatritemp.h b/src/mesa/swrast/s_aatritemp.h
index 64da824bed..354dd48abe 100644
--- a/src/mesa/swrast/s_aatritemp.h
+++ b/src/mesa/swrast/s_aatritemp.h
@@ -1,4 +1,4 @@
-/* $Id: s_aatritemp.h,v 1.13 2001/05/10 18:01:19 brianp Exp $ */
+/* $Id: s_aatritemp.h,v 1.14 2001/05/15 16:18:13 brianp Exp $ */
/*
* Mesa 3-D graphics library
@@ -51,12 +51,17 @@
GLint iyMin, iyMax;
GLfloat yMin, yMax;
GLboolean ltor;
- GLfloat majDx, majDy;
+ GLfloat majDx, majDy; /* major (i.e. long) edge dx and dy */
+
#ifdef DO_Z
GLfloat zPlane[4]; /* Z (depth) */
GLdepth z[MAX_WIDTH];
+#endif
+#ifdef DO_FOG
GLfloat fogPlane[4];
GLfloat fog[MAX_WIDTH];
+#else
+ GLfloat *fog = NULL;
#endif
#ifdef DO_RGBA
GLfloat rPlane[4], gPlane[4], bPlane[4], aPlane[4]; /* color */
@@ -134,14 +139,16 @@
ctx->OcclusionResult = GL_TRUE;
#endif
- /* plane setup */
+ /* Plane equation setup:
+ * We evaluate plane equations at window (x,y) coordinates in order
+ * to compute color, Z, fog, texcoords, etc. This isn't terribly
+ * efficient but it's easy and reliable.
+ */
#ifdef DO_Z
compute_plane(p0, p1, p2, p0[2], p1[2], p2[2], zPlane);
- compute_plane(p0, p1, p2,
- v0->fog,
- v1->fog,
- v2->fog,
- fogPlane);
+#endif
+#ifdef DO_FOG
+ compute_plane(p0, p1, p2, v0->fog, v1->fog, v2->fog, fogPlane);
#endif
#ifdef DO_RGBA
if (ctx->Light.ShadeModel == GL_SMOOTH) {
@@ -238,6 +245,12 @@
}
#endif
+ /* Begin bottom-to-top scan over the triangle.
+ * The long edge will either be on the left or right side of the
+ * triangle. We always scan from the long edge toward the shorter
+ * edges, stopping when we find that coverage = 0. If the long edge
+ * is on the left we scan left-to-right. Else, we scan right-to-left.
+ */
yMin = vMin->win[1];
yMax = vMax->win[1];
iyMin = (int) yMin;
@@ -250,7 +263,7 @@
const float *pMax = vMax->win;
const float dxdy = majDx / majDy;
const float xAdj = dxdy < 0.0F ? -dxdy : 0.0F;
- float x = vMin->win[0] - (yMin - iyMin) * dxdy;
+ float x = pMin[0] - (yMin - iyMin) * dxdy;
int iy;
for (iy = iyMin; iy < iyMax; iy++, x += dxdy) {
GLint ix, startX = (GLint) (x - xAdj);
@@ -272,6 +285,8 @@
const GLfloat cx = ix + 0.5F, cy = iy + 0.5F;
#ifdef DO_Z
z[count] = (GLdepth) solve_plane(cx, cy, zPlane);
+#endif
+#ifdef DO_FOG
fog[count] = solve_plane(cx, cy, fogPlane);
#endif
#ifdef DO_RGBA
@@ -366,7 +381,7 @@
const GLfloat *pMax = vMax->win;
const GLfloat dxdy = majDx / majDy;
const GLfloat xAdj = dxdy > 0 ? dxdy : 0.0F;
- GLfloat x = vMin->win[0] - (yMin - iyMin) * dxdy;
+ GLfloat x = pMin[0] - (yMin - iyMin) * dxdy;
GLint iy;
for (iy = iyMin; iy < iyMax; iy++, x += dxdy) {
GLint ix, left, startX = (GLint) (x + xAdj);
@@ -394,6 +409,8 @@
const GLfloat cx = ix + 0.5F, cy = iy + 0.5F;
#ifdef DO_Z
z[ix] = (GLdepth) solve_plane(cx, cy, zPlane);
+#endif
+#ifdef DO_FOG
fog[ix] = solve_plane(cx, cy, fogPlane);
#endif
#ifdef DO_RGBA
@@ -509,6 +526,10 @@
#undef DO_Z
#endif
+#ifdef DO_FOG
+#undef DO_FOG
+#endif
+
#ifdef DO_RGBA
#undef DO_RGBA
#endif