progs/tests: new test program for exercising cylindrical tex wrap mode

progs/tests/Makefile

@@ -41,6 +41,7 @@ SOURCES = \
 	copypixrate.c \
 	crossbar.c \
 	cva.c \
+	cylwrap.c \
 	drawbuffers.c \
 	drawbuffers2.c \
 	exactrast.c \

progs/tests/SConscript

@@ -45,6 +45,7 @@ progs = [
     'copypixrate',
     'crossbar',
     'cva',
+    'cylwrap',
     'drawbuffers',
     'drawbuffers2',
     'exactrast',

progs/tests/cylwrap.c

@@ -0,0 +1,204 @@
+/*
+ * Test cylindrical texcoord wrapping
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/glut.h>
+
+static int Win;
+static int WinWidth = 600, WinHeight = 400;
+static GLboolean CylWrap = GL_TRUE;
+
+
+
+static void
+PrintString(const char *s)
+{
+   while (*s) {
+      glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
+      s++;
+   }
+}
+
+
+static void
+DrawSample(GLboolean wrap)
+{
+   float p;
+
+   glEnable(GL_TEXTURE_2D);
+
+   /* texured quad */
+   glBegin(GL_QUAD_STRIP);
+   for (p = 0.0; p <= 1.001; p += 0.1) {
+      float x = -2.0 + p * 4.0;
+      float s = p + 0.5;
+      if (wrap && s > 1.0)
+         s -= 1.0;
+      glTexCoord2f(s, 0);  glVertex2f(x, -1);
+      glTexCoord2f(s, 1);  glVertex2f(x, +1);
+   }
+   glEnd();
+
+   glDisable(GL_TEXTURE_2D);
+
+   /* hash marks */
+   glColor3f(0,0,0);
+   glBegin(GL_LINES);
+   for (p = 0.0; p <= 1.001; p += 0.1) {
+      float x = -2.0 + p * 4.0;
+      glVertex2f(x, -1.1);
+      glVertex2f(x, -0.8);
+   }
+   glEnd();
+
+   /* labels */
+   glColor3f(1,1,1);
+   for (p = 0.0; p <= 1.001; p += 0.1) {
+      char str[100];
+      float x = -2.0 + p * 4.0;
+      float s = p + 0.5;
+
+      if (wrap && s > 1.0)
+         s -= 1.0;
+
+      sprintf(str, "%3.1f", s);
+      glRasterPos2f(x, -1.2);
+      glBitmap(0, 0, 0, 0, -11, 0, NULL);
+      PrintString(str);
+      if (p == 0.0) {
+         glBitmap(0, 0, 0, 0, -55, 0, NULL);
+         PrintString("s =");
+      }
+   }
+}
+
+
+static void
+Draw(void)
+{
+   glClear(GL_COLOR_BUFFER_BIT);
+
+   glPushMatrix();
+      glTranslatef(0, +1.2, 0);
+      DrawSample(GL_FALSE);
+   glPopMatrix();
+
+   /* set Mesa back-door state for testing cylindrical wrap mode */
+   if (CylWrap)
+      glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_PRIORITY, 0.125);
+
+   glPushMatrix();
+      glTranslatef(0, -1.2, 0);
+      DrawSample(GL_TRUE);
+   glPopMatrix();
+
+   glTexParameterf(GL_TEXTURE_2D, GL_TEXTURE_PRIORITY, 1.0);
+
+   glutSwapBuffers();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+   WinWidth = width;
+   WinHeight = height;
+   glViewport(0, 0, width, height);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+   glTranslatef(0.0, 0.0, -15.0);
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+   const GLfloat step = 3.0;
+   (void) x;
+   (void) y;
+   switch (key) {
+   case 'c':
+   case 'C':
+      CylWrap = !CylWrap;
+      if (CylWrap)
+         printf("Cylindrical wrap on.\n");
+      else
+         printf("Cylindrical wrap off.\n");
+      break;
+   case 27:
+      glutDestroyWindow(Win);
+      exit(0);
+      break;
+   }
+   glutPostRedisplay();
+}
+
+
+static void
+MakeSineWaveTexture(void)
+{
+   GLubyte tex[128][512][4];
+   int i, j;
+
+   for (j = 0; j < 128; j++) {
+      for (i = 0; i < 512; i++) {
+         float x = i / 511.0 * 2.0 * M_PI + M_PI * 0.5;
+         float y0 = sin(x) * 0.5 + 0.5;
+         int jy0 = y0 * 128;
+         float y1 = sin(x + M_PI) * 0.5 + 0.5;
+         int jy1 = y1 * 128;
+         if (j < jy0)
+            tex[j][i][0] = 0xff;
+         else
+            tex[j][i][0] = 0;
+         if (j < jy1)
+            tex[j][i][1] = 0xff;
+         else
+            tex[j][i][1] = 0;
+         tex[j][i][2] = 0;
+         tex[j][i][3] = 0xff;
+      }
+   }
+
+   glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, 512, 128, 0,
+                GL_RGBA, GL_UNSIGNED_BYTE, tex);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+   glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+   glTexEnvi(GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_REPLACE);
+}
+
+
+static void
+Init(void)
+{
+   glBindTexture(GL_TEXTURE_2D, 5);
+   MakeSineWaveTexture();
+
+   glClearColor(0.5, 0.5, 0.5, 0.0);
+   glPointSize(3.0);
+
+   printf("Press 'c' to toggle cylindrical wrap mode.\n");
+}
+
+
+int
+main(int argc, char *argv[])
+{
+   glutInit(&argc, argv);
+   glutInitWindowSize(WinWidth, WinHeight);
+   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE);
+   Win = glutCreateWindow(argv[0]);
+   glutReshapeFunc(Reshape);
+   glutKeyboardFunc(Key);
+   glutDisplayFunc(Draw);
+   Init();
+   glutMainLoop();
+   return 0;
+}