Attachment 29758 Details for Bug 24083 – test program

test program

vbo-draw-bug.c (text/x-csrc), 2.91 KB, created by Brian Paul on 2009-09-22 08:31:03 UTC

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Creator: Brian Paul

Created: 2009-09-22 08:31:03 UTC

Size: 2.91 KB

patch

obsolete

>/**
> * Compare VBO drawing vs. non-VBO drawing.
> * Exercises an i965 bug in which drawing is not flushed before the
> * contents of a VBO are changed.
> *
> * In VBO mode, all four of the blended, yellow quads get drawn on top of
> * each other in the last/right position.
> */
>
>#define GL_GLEXT_PROTOTYPES
>
>#include <stdio.h>
>#include <stdlib.h>
>#include <string.h>
>#include <math.h>
>#include <GL/glut.h>
>
>static int Win;
>static int WinWidth = 400, WinHeight = 400;
>static GLuint VBO = 0;
>static GLboolean UseVBO = GL_TRUE;
>
>
>/**
> * Draw a grid of textured boxes.
> * Vertex data is in a VBO.
> * Update the texture image/color prior to drawing each quad.
> */
>static void
>Draw(void)
>{
>   static const GLfloat verts[4][2] = {
>      /* X    Y     */
>      { 0.1, 0.1,   },
>      { 0.9, 0.1,   },
>      { 0.9, 0.9,   },
>      { 0.1, 0.9,   }
>   };
>   GLfloat verts2[4][2];
>
>   const GLfloat dx =4* 2.0 / 16;
>   GLfloat x;
>
>   if (UseVBO) {
>      glBindBufferARB(GL_ARRAY_BUFFER_ARB, VBO);
>      glBufferDataARB(GL_ARRAY_BUFFER_ARB, sizeof(verts2), verts2,
>                      GL_DYNAMIC_DRAW_ARB);
>      glVertexPointer(2, GL_FLOAT, 2 * sizeof(GLfloat), (void *) 0);
>   }
>   else {
>      glBindBufferARB(GL_ARRAY_BUFFER_ARB, 0);
>      glVertexPointer(2, GL_FLOAT, 2 * sizeof(GLfloat), &verts2[0][0]);
>   }
>
>   glEnableClientState(GL_VERTEX_ARRAY);
>
>   glClear(GL_COLOR_BUFFER_BIT);
>
>   /* draw four quads */
>   for (x = -1.0; x < 1.0; x += dx) {
>      GLuint i;
>
>      /* copmute translate vertices for this quad */
>      for (i = 0; i < 4; i++) {
>         verts2[i][0] = verts[i][0] / 4.0 + x;
>         verts2[i][1] = verts[i][1] / 4.0 + 0.0;
>      }
>      if (UseVBO)
>         glBufferSubDataARB(GL_ARRAY_BUFFER_ARB, 0, sizeof(verts2), verts2);
>      
>      glDrawArrays(GL_TRIANGLE_FAN, 0, 4);
>   }
>
>   glutSwapBuffers();
>}
>
>
>static void
>Reshape(int width, int height)
>{
>   WinWidth = width;
>   WinHeight = height;
>   glViewport(0, 0, width, height);
>   glMatrixMode(GL_PROJECTION);
>   glLoadIdentity();
>   glOrtho(-1.0, 1.0, -1.0, 1.0, -1.0, 1.0);
>   glMatrixMode(GL_MODELVIEW);
>   glLoadIdentity();
>}
>
>
>static void
>Key(unsigned char key, int x, int y)
>{
>   (void) x;
>   (void) y;
>   switch (key) {
>   case 'v':
>   case 'V':
>      UseVBO = !UseVBO;
>      printf("Use VBO: %d\n", UseVBO);
>      break;
>   case 27:
>      glutDestroyWindow(Win);
>      exit(0);
>      break;
>   }
>   glutPostRedisplay();
>}
>
>
>static void
>Init(void)
>{
>   glClearColor(0.2, 0.2, 0.8, 1.0);
>   glGenBuffersARB(1, &VBO);
>
>   glColor4f(1, 1, 0, 0.5);
>
>   glEnable(GL_BLEND);
>   glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
>
>   printf("Press 'v' to toggle VBO drawing\n");
>}
>
>
>int
>main(int argc, char *argv[])
>{
>   glutInit(&argc, argv);
>   glutInitWindowSize(WinWidth, WinHeight);
>   glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
>   Win = glutCreateWindow(argv[0]);
>   glutReshapeFunc(Reshape);
>   glutKeyboardFunc(Key);
>   glutDisplayFunc(Draw);
>   Init();
>   glutMainLoop();
>   return 0;
>}

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Attachments on bug 24083: 29758

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