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/*
* GLSL noise demo.
*
* Michal Krol
* 20 February 2006
*
* Based on the original demo by:
* Stefan Gustavson (stegu@itn.liu.se) 2004, 2005
*/
#ifdef WIN32
#include <windows.h>
#endif
#include <stdio.h>
#include <stdlib.h>
#include <GL/gl.h>
#include <GL/glut.h>
#include <GL/glext.h>
#ifdef WIN32
#define GETPROCADDRESS(F) wglGetProcAddress(F)
#else
#define GETPROCADDRESS(F) glutGetProcAddress(F)
#endif
static GLhandleARB fragShader;
static GLhandleARB vertShader;
static GLhandleARB program;
static GLint uTime;
static GLint t0 = 0;
static GLint frames = 0;
static GLfloat u_time = 0.0f;
static PFNGLCREATESHADEROBJECTARBPROC glCreateShaderObjectARB = NULL;
static PFNGLSHADERSOURCEARBPROC glShaderSourceARB = NULL;
static PFNGLCOMPILESHADERARBPROC glCompileShaderARB = NULL;
static PFNGLCREATEPROGRAMOBJECTARBPROC glCreateProgramObjectARB = NULL;
static PFNGLATTACHOBJECTARBPROC glAttachObjectARB = NULL;
static PFNGLLINKPROGRAMARBPROC glLinkProgramARB = NULL;
static PFNGLUSEPROGRAMOBJECTARBPROC glUseProgramObjectARB = NULL;
static PFNGLGETUNIFORMLOCATIONARBPROC glGetUniformLocationARB = NULL;
static PFNGLUNIFORM1FARBPROC glUniform1fARB = NULL;
static void Redisplay (void)
{
GLint t;
glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glUniform1fARB (uTime, 0.5f * u_time);
glPushMatrix ();
glutSolidSphere (2.0, 20, 10);
glPopMatrix ();
glutSwapBuffers();
frames++;
t = glutGet (GLUT_ELAPSED_TIME);
if (t - t0 >= 5000) {
GLfloat seconds = (GLfloat) (t - t0) / 1000.0f;
GLfloat fps = frames / seconds;
printf ("%d frames in %6.3f seconds = %6.3f FPS\n", frames, seconds, fps);
fflush(stdout);
t0 = t;
frames = 0;
}
}
static void Idle (void)
{
u_time += 0.1f;
glutPostRedisplay ();
}
static void Reshape (int width, int height)
{
glViewport (0, 0, width, height);
glMatrixMode (GL_PROJECTION);
glLoadIdentity ();
glFrustum (-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
glMatrixMode (GL_MODELVIEW);
glLoadIdentity ();
glTranslatef (0.0f, 0.0f, -15.0f);
}
static void Key (unsigned char key, int x, int y)
{
(void) x;
(void) y;
switch (key)
{
case 27:
exit(0);
break;
}
glutPostRedisplay ();
}
static void Init (void)
{
static const char *fragShaderText =
"uniform float time;\n"
"varying vec3 position;\n"
"void main () {\n"
" gl_FragColor = vec4 (vec3 (0.5 + 0.5 * noise1 (vec4 (position, time))), 1.0);\n"
"}\n"
;
static const char *vertShaderText =
"varying vec3 position;\n"
"void main () {\n"
" gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
" position = 4.0 * gl_Vertex.xyz;\n"
"}\n"
;
if (!glutExtensionSupported ("GL_ARB_fragment_shader"))
{
printf ("Sorry, this demo requires GL_ARB_fragment_shader\n");
exit(1);
}
if (!glutExtensionSupported ("GL_ARB_shader_objects"))
{
printf ("Sorry, this demo requires GL_ARB_shader_objects\n");
exit(1);
}
if (!glutExtensionSupported ("GL_ARB_shading_language_100"))
{
printf ("Sorry, this demo requires GL_ARB_shading_language_100\n");
exit(1);
}
if (!glutExtensionSupported ("GL_ARB_vertex_shader"))
{
printf ("Sorry, this demo requires GL_ARB_vertex_shader\n");
exit(1);
}
glCreateShaderObjectARB = (PFNGLCREATESHADEROBJECTARBPROC)
GETPROCADDRESS("glCreateShaderObjectARB");
glShaderSourceARB = (PFNGLSHADERSOURCEARBPROC)
GETPROCADDRESS("glShaderSourceARB");
glCompileShaderARB = (PFNGLCOMPILESHADERARBPROC)
GETPROCADDRESS("glCompileShaderARB");
glCreateProgramObjectARB = (PFNGLCREATEPROGRAMOBJECTARBPROC)
GETPROCADDRESS("glCreateProgramObjectARB");
glAttachObjectARB = (PFNGLATTACHOBJECTARBPROC)
GETPROCADDRESS("glAttachObjectARB");
glLinkProgramARB = (PFNGLLINKPROGRAMARBPROC)
GETPROCADDRESS ("glLinkProgramARB");
glUseProgramObjectARB = (PFNGLUSEPROGRAMOBJECTARBPROC)
GETPROCADDRESS("glUseProgramObjectARB");
glGetUniformLocationARB = (PFNGLGETUNIFORMLOCATIONARBPROC)
GETPROCADDRESS("glGetUniformLocationARB");
glUniform1fARB = (PFNGLUNIFORM1FARBPROC)
GETPROCADDRESS("glUniform1fARB");
fragShader = glCreateShaderObjectARB (GL_FRAGMENT_SHADER_ARB);
glShaderSourceARB (fragShader, 1, &fragShaderText, NULL);
glCompileShaderARB (fragShader);
vertShader = glCreateShaderObjectARB (GL_VERTEX_SHADER_ARB);
glShaderSourceARB (vertShader, 1, &vertShaderText, NULL);
glCompileShaderARB (vertShader);
program = glCreateProgramObjectARB ();
glAttachObjectARB (program, fragShader);
glAttachObjectARB (program, vertShader);
glLinkProgramARB (program);
glUseProgramObjectARB (program);
uTime = glGetUniformLocationARB (program, "time");
glClearColor (0.0f, 0.1f, 0.3f, 1.0f);
glEnable (GL_CULL_FACE);
glEnable (GL_DEPTH_TEST);
printf ("GL_RENDERER = %s\n", (const char *) glGetString (GL_RENDERER));
}
int main (int argc, char *argv[])
{
glutInit (&argc, argv);
glutInitWindowSize (200, 200);
glutInitDisplayMode (GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
glutCreateWindow (argv[0]);
glutReshapeFunc (Reshape);
glutKeyboardFunc (Key);
glutDisplayFunc (Redisplay);
glutIdleFunc (Idle);
Init ();
glutMainLoop ();
return 0;
}
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