test multitexture and vertex arrays

progs/tests/multitexarray.c

@@ -0,0 +1,238 @@
+/*
+ * Test vertex arrays and multitexture.
+ * Press 'a' to toggle vertex arrays on/off.
+ * When you run this program you should see a square with four colors:
+ *
+ *      +------+------+
+ *      |yellow| pink |
+ *      +------+------+
+ *      |green | blue |
+ *      +------+------+
+ */
+
+
+#include <assert.h>
+#include <math.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "GL/glut.h"
+
+static GLuint Window = 0;
+
+static GLuint TexObj[2];
+static GLfloat Angle = 0.0f;
+static GLboolean UseArrays = 1, Anim = 0;
+
+static GLfloat VertArray[4][2] = {
+   {-1.2, -1.2}, {1.2, -1.2}, {1.2, 1.2}, {-1.2, 1.2}
+};
+
+static GLfloat Tex0Array[4][2] = {
+   {0, 0}, {1, 0}, {1, 1}, {0, 1}
+};
+
+static GLfloat Tex1Array[4][2] = {
+   {0, 0}, {1, 0}, {1, 1}, {0, 1}
+};
+
+
+static void init_arrays(void)
+{
+   glVertexPointer(2, GL_FLOAT, 0, VertArray);
+   glEnableClientState(GL_VERTEX_ARRAY);
+
+   glClientActiveTextureARB(GL_TEXTURE0_ARB);
+   glTexCoordPointer(2, GL_FLOAT, 0, Tex0Array);
+   glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+
+   glClientActiveTextureARB(GL_TEXTURE1_ARB);
+   glTexCoordPointer(2, GL_FLOAT, 0, Tex1Array);
+   glEnableClientState(GL_TEXTURE_COORD_ARRAY);
+}
+
+
+static void draw( void )
+{
+   glClear( GL_COLOR_BUFFER_BIT );
+
+   glColor3f( 0.0, 0.0, 0.0 );
+
+   /* draw first polygon */
+   glPushMatrix();
+      glRotatef( Angle, 0.0, 0.0, 1.0 );
+
+      if (UseArrays) {
+         glDrawArrays(GL_POLYGON, 0, 4);
+      }
+      else {
+         glBegin( GL_POLYGON );
+            glTexCoord2f( 0.0, 0.0 );
+            glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 0.0);
+            glVertex2f( -1.0, -1.0 );
+
+            glTexCoord2f( 1.0, 0.0 );
+            glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 1.0, 0.0);
+            glVertex2f(  1.0, -1.0 );
+
+            glTexCoord2f( 1.0, 1.0 );
+            glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 1.0, 1.0);
+            glVertex2f(  1.0,  1.0 );
+
+            glTexCoord2f( 0.0, 1.0 );
+            glMultiTexCoord2fARB(GL_TEXTURE1_ARB, 0.0, 1.0);
+            glVertex2f( -1.0,  1.0 );
+         glEnd();
+      }
+
+   glPopMatrix();
+
+   glutSwapBuffers();
+}
+
+
+
+static void idle( void )
+{
+   Angle += 2.0;
+   glutPostRedisplay();
+}
+
+
+
+/* change view Angle, exit upon ESC */
+static void key(unsigned char k, int x, int y)
+{
+   (void) x;
+   (void) y;
+   switch (k) {
+      case 'a':
+         UseArrays = !UseArrays;
+         printf("UseArrays: %d\n", UseArrays);
+         break;
+      case ' ':
+         Anim = !Anim;
+         if (Anim)
+            glutIdleFunc(idle);
+         else
+            glutIdleFunc(NULL);
+         break;
+      case 27:
+         glDeleteTextures( 2, TexObj );
+         glutDestroyWindow(Window);
+         exit(0);
+   }
+   glutPostRedisplay();
+}
+
+
+
+/* new window size or exposure */
+static void reshape( int width, int height )
+{
+   glViewport(0, 0, (GLint)width, (GLint)height);
+   glMatrixMode(GL_PROJECTION);
+   glLoadIdentity();
+   /*   glOrtho( -3.0, 3.0, -3.0, 3.0, -10.0, 10.0 );*/
+   glFrustum( -2.0, 2.0, -2.0, 2.0, 6.0, 20.0 );
+   glMatrixMode(GL_MODELVIEW);
+   glLoadIdentity();
+   glTranslatef( 0.0, 0.0, -8.0 );
+}
+
+
+static void init( void )
+{
+   static int width=8, height=8;
+   GLubyte tex[64][3];
+   GLint i, j;
+
+   /* generate texture object IDs */
+   glGenTextures( 2, TexObj );
+
+   /*
+    * setup first texture object
+    */
+   glActiveTextureARB(GL_TEXTURE0_ARB);
+   glEnable( GL_TEXTURE_2D );
+   glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_ADD );
+
+   glBindTexture( GL_TEXTURE_2D, TexObj[0] );
+   assert(glIsTexture(TexObj[0]));
+
+   /* red over black */
+   for (i=0;i<height;i++) {
+      for (j=0;j<width;j++) {
+         int p = i*width+j;
+         if (i < height / 2) {
+            tex[p][0] = 0;   tex[p][1] = 0;   tex[p][2] = 0;
+         }
+         else {
+            tex[p][0] = 255;   tex[p][1] = 0;     tex[p][2] = 0;
+         }
+      }
+   }
+
+   glTexImage2D( GL_TEXTURE_2D, 0, 3, width, height, 0,
+                 GL_RGB, GL_UNSIGNED_BYTE, tex );
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
+
+
+   /*
+    * setup second texture object
+    */
+   glActiveTextureARB(GL_TEXTURE1_ARB);
+   glEnable( GL_TEXTURE_2D );
+   glTexEnvi( GL_TEXTURE_ENV, GL_TEXTURE_ENV_MODE, GL_ADD );
+
+   glBindTexture( GL_TEXTURE_2D, TexObj[1] );
+   assert(glIsTexture(TexObj[1]));
+
+   /* left=green, right = blue */
+   for (i=0;i<height;i++) {
+      for (j=0;j<width;j++) {
+         int p = i*width+j;
+         if (j < width / 2) {
+            tex[p][0] = 0;     tex[p][1] = 255;   tex[p][2] = 0;
+         }
+         else {
+            tex[p][0] = 0;     tex[p][1] = 0;     tex[p][2] = 255;
+         }
+      }
+   }
+   glTexImage2D( GL_TEXTURE_2D, 0, 3, width, height, 0,
+                 GL_RGB, GL_UNSIGNED_BYTE, tex );
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST );
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST );
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT );
+   glTexParameteri( GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT );
+}
+
+
+
+int main( int argc, char *argv[] )
+{
+   glutInit(&argc, argv);
+   glutInitWindowPosition(0, 0);
+   glutInitWindowSize(300, 300);
+   glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
+
+   Window = glutCreateWindow("Texture Objects");
+   if (!Window) {
+      exit(1);
+   }
+
+   init();
+   init_arrays();
+
+   glutReshapeFunc( reshape );
+   glutKeyboardFunc( key );
+   if (Anim)
+      glutIdleFunc( idle );
+   glutDisplayFunc( draw );
+   glutMainLoop();
+   return 0;
+}