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-rw-r--r--progs/tests/Makefile1
-rw-r--r--progs/tests/SConscript1
-rw-r--r--progs/tests/persp_hint.c149
3 files changed, 151 insertions, 0 deletions
diff --git a/progs/tests/Makefile b/progs/tests/Makefile
index f3f1aea944..23fe3c35c1 100644
--- a/progs/tests/Makefile
+++ b/progs/tests/Makefile
@@ -67,6 +67,7 @@ SOURCES = \
no_s3tc.c \
packedpixels.c \
pbo.c \
+ persp_hint.c \
prog_parameter.c \
quads.c \
random.c \
diff --git a/progs/tests/SConscript b/progs/tests/SConscript
index 9d89ff6a0d..9e3a646f80 100644
--- a/progs/tests/SConscript
+++ b/progs/tests/SConscript
@@ -90,6 +90,7 @@ progs = [
'no_s3tc',
'packedpixels',
'pbo',
+ 'persp_hint',
'prog_parameter',
'quads',
'random',
diff --git a/progs/tests/persp_hint.c b/progs/tests/persp_hint.c
new file mode 100644
index 0000000000..27140d1f56
--- /dev/null
+++ b/progs/tests/persp_hint.c
@@ -0,0 +1,149 @@
+/*
+ * Test the GL_PERSPECTIVE_CORRECTION_HINT setting and its effect on
+ * color interpolation.
+ *
+ * Press 'i' to toggle between GL_NICEST/GL_FASTEST/GL_DONT_CARE.
+ *
+ * Depending on the driver, the hint may make a difference, or not.
+ */
+
+
+#include <stdlib.h>
+#include <stdio.h>
+#include <GL/glut.h>
+
+
+static GLenum PerspHint = GL_DONT_CARE;
+
+
+static void
+init(void)
+{
+ GLubyte image[256][256][4];
+ GLuint i, j;
+ for (i = 0; i < 256; i++) {
+ for (j = 0; j < 256; j++) {
+ image[i][j][0] = j;
+ image[i][j][1] = j;
+ image[i][j][2] = j;
+ image[i][j][3] = 255;
+ }
+ }
+ glTexImage2D(GL_TEXTURE_2D, 0, 4, 256, 256, 0,
+ GL_RGBA, GL_UNSIGNED_BYTE, image);
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
+ glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
+ glTexEnvf(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_DECAL);
+
+ printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
+}
+
+
+static void
+display(void)
+{
+ switch (PerspHint) {
+ case GL_NICEST:
+ printf("hint = GL_NICEST\n");
+ break;
+ case GL_FASTEST:
+ printf("hint = GL_FASTEST\n");
+ break;
+ case GL_DONT_CARE:
+ printf("hint = GL_DONT_CARE\n");
+ break;
+ default:
+ ;
+ }
+
+ glClear(GL_COLOR_BUFFER_BIT);
+
+#if 1
+ glBegin(GL_QUADS);
+ /* exercise perspective interpolation */
+ glColor3f(0.0, 0.0, 0.0); glVertex3f(-1.0, -1.0, -1.0);
+ glColor3f(0.0, 0.0, 0.0); glVertex3f(-1.0, 1.0, -1.0);
+ glColor3f(0.0, 1.0, 0.0); glVertex3f( 7.0, 1.0, -7.0);
+ glColor3f(0.0, 1.0, 0.0); glVertex3f( 7.0, -1.0, -7.0);
+
+ /* stripe of linear interpolation */
+ glColor3f(0.0, 0.0, 0.0); glVertex3f(-1.0, -0.1, -1.001);
+ glColor3f(0.0, 0.0, 0.0); glVertex3f(-1.0, 0.1, -1.001);
+ glColor3f(0.0, 1.0, 0.0); glVertex3f( 1.0, 0.1, -1.001);
+ glColor3f(0.0, 1.0, 0.0); glVertex3f( 1.0, -0.1, -1.001);
+ glEnd();
+#else
+ glEnable(GL_TEXTURE_2D);
+ glBegin(GL_QUADS);
+ glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, 0.0, -1.0);
+ glTexCoord2f(0.0, 1.0); glVertex3f(-1.0, 1.0, -1.0);
+ glTexCoord2f(1.0, 1.0); glVertex3f( 5.0, 1.0, -7.0);
+ glTexCoord2f(1.0, 0.0); glVertex3f( 5.0, 0.0, -7.0);
+
+ glTexCoord2f(0.0, 0.0); glVertex3f(-1.0, -1.0, -1.001);
+ glTexCoord2f(0.0, 1.0); glVertex3f(-1.0, 0.0, -1.001);
+ glTexCoord2f(1.0, 1.0); glVertex3f( 1.0, 0.0, -1.001);
+ glTexCoord2f(1.0, 0.0); glVertex3f( 1.0, -1.0, -1.001);
+ glEnd();
+#endif
+
+ glFlush();
+}
+
+
+static void
+reshape(int w, int h)
+{
+ glViewport(0, 0, w, h);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ gluPerspective(90.0, (GLfloat) w / h, 1.0, 300.0);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+}
+
+
+static void
+key(unsigned char k, int x, int y)
+{
+ switch (k) {
+ case 27: /* Escape */
+ exit(0);
+ break;
+ case 'i':
+ if (PerspHint == GL_FASTEST)
+ PerspHint = GL_NICEST;
+ else if (PerspHint == GL_NICEST)
+ PerspHint = GL_DONT_CARE;
+ else
+ PerspHint = GL_FASTEST;
+ glHint(GL_PERSPECTIVE_CORRECTION_HINT, PerspHint);
+ break;
+ default:
+ return;
+ }
+ glutPostRedisplay();
+}
+
+
+int
+main(int argc, char** argv)
+{
+ glutInit(&argc, argv);
+ glutInitDisplayMode (GLUT_SINGLE | GLUT_RGB);
+ glutInitWindowSize (500, 500);
+ glutCreateWindow (argv[0]);
+ glutReshapeFunc (reshape);
+ glutDisplayFunc(display);
+ glutKeyboardFunc(key);
+
+ printf("Main quad: perspective projection\n");
+ printf("Middle stripe: linear interpolation\n");
+ printf("Press 'i' to toggle interpolation hint\n");
+ init();
+
+ glutMainLoop();
+ return 0;
+}