1/* Basic VBO */
2
3#include <assert.h>
4#include <string.h>
5#include <stdio.h>
6#include <stdlib.h>
7#include <math.h>
8#include <GL/glew.h>
9#include "glut_wrap.h"
10
11
12struct {
13   GLfloat pos[4][4];
14   GLfloat col[4][4];
15} verts =
16{
17   /* Position: a quad
18    */
19   {
20      {  0.9, -0.9, 0.0, 1.0 },
21      {  0.9,  0.9, 0.0, 1.0 },
22      { -0.9,  0.9, 0.0, 1.0 },
23      { -0.9, -0.9, 0.0, 1.0 },
24   },
25
26   /* Color: all red
27    */
28   {
29      { 1.0, 0.0, 0.0, 1.0 },
30      { 1.0, 0.0, 0.0, 1.0 },
31      { 1.0, 0.0, 0.0, 1.0 },
32      { 1.0, 0.0, 0.0, 1.0 },
33   },
34
35
36};
37
38GLuint arrayObj, elementObj;
39
40static void Init( void )
41{
42   GLint errnum;
43   GLuint prognum;
44
45   static const char *prog1 =
46      "!!ARBvp1.0\n"
47      "MOV  result.color, vertex.color;\n"
48      "MOV  result.position, vertex.position;\n"
49      "END\n";
50
51   glGenProgramsARB(1, &prognum);
52   glBindProgramARB(GL_VERTEX_PROGRAM_ARB, prognum);
53   glProgramStringARB(GL_VERTEX_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB,
54		      strlen(prog1), (const GLubyte *) prog1);
55
56   assert(glIsProgramARB(prognum));
57   errnum = glGetError();
58   printf("glGetError = %d\n", errnum);
59   if (errnum != GL_NO_ERROR)
60   {
61      GLint errorpos;
62
63      glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &errorpos);
64      printf("errorpos: %d\n", errorpos);
65      printf("%s\n", (char *)glGetString(GL_PROGRAM_ERROR_STRING_ARB));
66   }
67
68
69   glEnableClientState( GL_VERTEX_ARRAY );
70   glEnableClientState( GL_COLOR_ARRAY );
71
72   glGenBuffersARB(1, &arrayObj);
73   glBindBufferARB(GL_ARRAY_BUFFER_ARB, arrayObj);
74   glBufferDataARB(GL_ARRAY_BUFFER_ARB, sizeof(verts), &verts, GL_STATIC_DRAW_ARB);
75
76   glVertexPointer( 4, GL_FLOAT, sizeof(verts.pos[0]), 0 );
77   glColorPointer( 4, GL_FLOAT, sizeof(verts.col[0]), (void *)(4*4*sizeof(float)) );
78
79}
80
81
82
83static void Display( void )
84{
85   glClearColor(0.3, 0.3, 0.3, 1);
86   glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
87
88   glEnable(GL_VERTEX_PROGRAM_ARB);
89
90   /* glDrawArrays( GL_TRIANGLES, 0, 3 ); */
91   /* glDrawArrays( GL_TRIANGLES, 1, 3 ); */
92   glDrawArrays( GL_QUADS, 0, 4 );
93
94   glFlush();
95}
96
97
98static void Reshape( int width, int height )
99{
100   glViewport( 0, 0, width, height );
101   glMatrixMode( GL_PROJECTION );
102   glLoadIdentity();
103   glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
104   glMatrixMode( GL_MODELVIEW );
105   glLoadIdentity();
106   /*glTranslatef( 0.0, 0.0, -15.0 );*/
107}
108
109
110static void Key( unsigned char key, int x, int y )
111{
112   (void) x;
113   (void) y;
114   switch (key) {
115      case 27:
116         exit(0);
117         break;
118   }
119   glutPostRedisplay();
120}
121
122
123
124
125int main( int argc, char *argv[] )
126{
127   glutInit( &argc, argv );
128   glutInitWindowPosition( 0, 0 );
129   glutInitWindowSize( 250, 250 );
130   glutInitDisplayMode( GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH );
131   glutCreateWindow(argv[0]);
132   glewInit();
133   glutReshapeFunc( Reshape );
134   glutKeyboardFunc( Key );
135   glutDisplayFunc( Display );
136   Init();
137   glutMainLoop();
138   return 0;
139}
140