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/*
* Test GL_ARB_vertex_buffer_object
*
* Brian Paul
* 16 Sep 2003
*/
#define GL_GLEXT_PROTOTYPES
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include <GL/glut.h>
#define NUM_OBJECTS 10
struct object
{
GLuint BufferID;
GLuint ElementsBufferID;
GLuint NumVerts;
GLuint VertexOffset;
GLuint ColorOffset;
GLuint NumElements;
};
static struct object Objects[NUM_OBJECTS];
static GLuint NumObjects;
static GLfloat Xrot = 0, Yrot = 0, Zrot = 0;
static GLboolean Anim = GL_TRUE;
static void CheckError(int line)
{
GLenum err = glGetError();
if (err) {
printf("GL Error %d at line %d\n", (int) err, line);
}
}
static void DrawObject( const struct object *obj )
{
glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID);
glVertexPointer(3, GL_FLOAT, 0, (void *) obj->VertexOffset);
glEnable(GL_VERTEX_ARRAY);
glColorPointer(3, GL_FLOAT, 0, (void *) obj->ColorOffset);
glEnable(GL_COLOR_ARRAY);
if (obj->NumElements > 0) {
/* indexed arrays */
glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, obj->ElementsBufferID);
glDrawElements(GL_LINE_LOOP, obj->NumElements, GL_UNSIGNED_INT, NULL);
}
else {
/* non-indexed arrays */
glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 0);
glDrawArrays(GL_LINE_LOOP, 0, obj->NumVerts);
}
}
static void Idle( void )
{
Zrot = 0.05 * glutGet(GLUT_ELAPSED_TIME);
glutPostRedisplay();
}
static void Display( void )
{
int i;
glClear( GL_COLOR_BUFFER_BIT );
for (i = 0; i < NumObjects; i++) {
float x = 5.0 * ((float) i / (NumObjects-1) - 0.5);
glPushMatrix();
glTranslatef(x, 0, 0);
glRotatef(Xrot, 1, 0, 0);
glRotatef(Yrot, 0, 1, 0);
glRotatef(Zrot, 0, 0, 1);
DrawObject(Objects + i);
glPopMatrix();
}
CheckError(__LINE__);
glutSwapBuffers();
}
static void Reshape( int width, int height )
{
float ar = (float) width / (float) height;
glViewport( 0, 0, width, height );
glMatrixMode( GL_PROJECTION );
glLoadIdentity();
glFrustum( -ar, ar, -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 'a':
Anim = !Anim;
if (Anim)
glutIdleFunc(Idle);
else
glutIdleFunc(NULL);
break;
case 'z':
Zrot -= step;
break;
case 'Z':
Zrot += step;
break;
case 27:
exit(0);
break;
}
glutPostRedisplay();
}
static void SpecialKey( int key, int x, int y )
{
const GLfloat step = 3.0;
(void) x;
(void) y;
switch (key) {
case GLUT_KEY_UP:
Xrot -= step;
break;
case GLUT_KEY_DOWN:
Xrot += step;
break;
case GLUT_KEY_LEFT:
Yrot -= step;
break;
case GLUT_KEY_RIGHT:
Yrot += step;
break;
}
glutPostRedisplay();
}
static void MakeObject1(struct object *obj)
{
GLfloat *v, *c;
glGenBuffersARB(1, &obj->BufferID);
glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID);
glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB);
v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
/* Make rectangle */
v[0] = -1; v[1] = -1; v[2] = 0;
v[3] = 1; v[4] = -1; v[5] = 0;
v[6] = 1; v[7] = 1; v[8] = 0;
v[9] = -1; v[10] = 1; v[11] = 0;
c = v + 12;
c[0] = 1; c[1] = 0; c[2] = 0;
c[3] = 1; c[4] = 0; c[5] = 0;
c[6] = 1; c[7] = 0; c[8] = 1;
c[9] = 1; c[10] = 0; c[11] = 1;
obj->NumVerts = 4;
obj->VertexOffset = 0;
obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts;
obj->NumElements = 0;
glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
}
static void MakeObject2(struct object *obj)
{
GLfloat *v, *c;
glGenBuffersARB(1, &obj->BufferID);
glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID);
glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB);
v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
/* Make triangle */
v[0] = -1; v[1] = -1; v[2] = 0;
v[3] = 1; v[4] = -1; v[5] = 0;
v[6] = 0; v[7] = 1; v[8] = 0;
c = v + 9;
c[0] = 0; c[1] = 1; c[2] = 0;
c[3] = 0; c[4] = 1; c[5] = 0;
c[6] = 1; c[7] = 1; c[8] = 0;
obj->NumVerts = 3;
obj->VertexOffset = 0;
obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts;
obj->NumElements = 0;
glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
}
static void MakeObject3(struct object *obj)
{
GLfloat *v, *c;
GLuint *i;
glGenBuffersARB(1, &obj->BufferID);
glBindBufferARB(GL_ARRAY_BUFFER_ARB, obj->BufferID);
glBufferDataARB(GL_ARRAY_BUFFER_ARB, 1000, NULL, GL_STATIC_DRAW_ARB);
v = (GLfloat *) glMapBufferARB(GL_ARRAY_BUFFER_ARB, GL_WRITE_ONLY_ARB);
/* Make rectangle */
v[0] = -1; v[1] = -0.5; v[2] = 0;
v[3] = 1; v[4] = -0.5; v[5] = 0;
v[6] = 1; v[7] = 0.5; v[8] = 0;
v[9] = -1; v[10] = 0.5; v[11] = 0;
c = v + 12;
c[0] = 0; c[1] = 0; c[2] = 1;
c[3] = 0; c[4] = 0; c[5] = 1;
c[6] = 0; c[7] = 1; c[8] = 1;
c[9] = 0; c[10] = 1; c[11] = 1;
obj->NumVerts = 4;
obj->VertexOffset = 0;
obj->ColorOffset = 3 * sizeof(GLfloat) * obj->NumVerts;
glUnmapBufferARB(GL_ARRAY_BUFFER_ARB);
/* Setup a buffer of indices to test the ELEMENTS path */
glGenBuffersARB(1, &obj->ElementsBufferID);
glBindBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, obj->ElementsBufferID);
glBufferDataARB(GL_ELEMENT_ARRAY_BUFFER_ARB, 100, NULL, GL_STATIC_DRAW_ARB);
i = (GLuint *) glMapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB, GL_READ_WRITE_ARB);
i[0] = 0;
i[1] = 1;
i[2] = 2;
i[3] = 3;
glUnmapBufferARB(GL_ELEMENT_ARRAY_BUFFER_ARB);
obj->NumElements = 4;
}
static void Init( void )
{
if (!glutExtensionSupported("GL_ARB_vertex_buffer_object")) {
printf("GL_ARB_vertex_buffer_object not found!\n");
exit(0);
}
printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
MakeObject1(Objects + 0);
MakeObject2(Objects + 1);
MakeObject3(Objects + 2);
NumObjects = 3;
}
int main( int argc, char *argv[] )
{
glutInit( &argc, argv );
glutInitWindowPosition( 0, 0 );
glutInitWindowSize( 600, 300 );
glutInitDisplayMode( GLUT_RGB | GLUT_DOUBLE );
glutCreateWindow(argv[0]);
glutReshapeFunc( Reshape );
glutKeyboardFunc( Key );
glutSpecialFunc( SpecialKey );
glutDisplayFunc( Display );
if (Anim)
glutIdleFunc(Idle);
Init();
glutMainLoop();
return 0;
}
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