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