progs/demos/glslnoise.c

   1 /*
   2  * GLSL noise demo.
   3  *
   4  * Michal Krol
   5  * 20 February 2006
   6  *
   7  * Based on the original demo by:
   8  * Stefan Gustavson (stegu@itn.liu.se) 2004, 2005
   9  */
  10
  11 #ifdef WIN32
  12 #include <windows.h>
  13 #endif
  14
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <GL/gl.h>
  18 #include <GL/glut.h>
  19 #include <GL/glext.h>
  20
  21 #ifdef WIN32
  22 #define GETPROCADDRESS(F) wglGetProcAddress(F)
  23 #else
  24 #define GETPROCADDRESS(F) glutGetProcAddress(F)
  25 #endif
  26
  27 static GLhandleARB fragShader;
  28 static GLhandleARB vertShader;
  29 static GLhandleARB program;
  30
  31 static GLint uTime;
  32
  33 static GLfloat u_time = 0.0f;
  34
  35 static PFNGLCREATESHADEROBJECTARBPROC glCreateShaderObjectARB = NULL;
  36 static PFNGLSHADERSOURCEARBPROC glShaderSourceARB = NULL;
  37 static PFNGLCOMPILESHADERARBPROC glCompileShaderARB = NULL;
  38 static PFNGLCREATEPROGRAMOBJECTARBPROC glCreateProgramObjectARB = NULL;
  39 static PFNGLATTACHOBJECTARBPROC glAttachObjectARB = NULL;
  40 static PFNGLLINKPROGRAMARBPROC glLinkProgramARB = NULL;
  41 static PFNGLUSEPROGRAMOBJECTARBPROC glUseProgramObjectARB = NULL;
  42 static PFNGLGETUNIFORMLOCATIONARBPROC glGetUniformLocationARB = NULL;
  43 static PFNGLUNIFORM1FARBPROC glUniform1fARB = NULL;
  44
  45 static void Redisplay (void)
  46 {
  47         glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  48
  49         glUniform1fARB (uTime, u_time);
  50
  51         glPushMatrix ();
  52         glutSolidSphere (2.0, 20, 10);
  53         glPopMatrix ();
  54
  55         glutSwapBuffers();
  56 }
  57
  58 static void Idle (void)
  59 {
  60         u_time += 0.1f;
  61         glutPostRedisplay ();
  62 }
  63
  64 static void Reshape (int width, int height)
  65 {
  66         glViewport (0, 0, width, height);
  67         glMatrixMode (GL_PROJECTION);
  68         glLoadIdentity ();
  69         glFrustum (-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  70         glMatrixMode (GL_MODELVIEW);
  71         glLoadIdentity ();
  72         glTranslatef (0.0f, 0.0f, -15.0f);
  73 }
  74
  75 static void Key (unsigned char key, int x, int y)
  76 {
  77         (void) x;
  78         (void) y;
  79
  80         switch (key)
  81         {
  82         case 27:
  83                 exit(0);
  84                 break;
  85         }
  86         glutPostRedisplay ();
  87 }
  88
  89 static void Init (void)
  90 {
  91         static const char *fragShaderText =
  92                 "uniform float time;\n"
  93                 "void main () {\n"
  94                 "       gl_FragColor = gl_Color * vec4 ((0.5 + 0.5 * vec3 (noise1 (\n"
  95                 "               vec4 (4.0 * gl_TexCoord[0].xyz, 0.5 * time)))), 1.0);\n"
  96                 "}\n"
  97         ;
  98         static const char *vertShaderText =
  99                 "void main () {\n"
 100                 "       gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
 101                 "       gl_TexCoord[0] = gl_Vertex;\n"
 102                 "       gl_FrontColor = gl_Color;\n"
 103                 "}\n"
 104         ;
 105
 106         if (!glutExtensionSupported ("GL_ARB_fragment_shader"))
 107         {
 108                 printf ("Sorry, this demo requires GL_ARB_fragment_shader\n");
 109                 exit(1);
 110         }
 111         if (!glutExtensionSupported ("GL_ARB_shader_objects"))
 112         {
 113                 printf ("Sorry, this demo requires GL_ARB_shader_objects\n");
 114                 exit(1);
 115         }
 116         if (!glutExtensionSupported ("GL_ARB_shading_language_100"))
 117         {
 118                 printf ("Sorry, this demo requires GL_ARB_shading_language_100\n");
 119                 exit(1);
 120         }
 121         if (!glutExtensionSupported ("GL_ARB_vertex_shader"))
 122         {
 123                 printf ("Sorry, this demo requires GL_ARB_vertex_shader\n");
 124                 exit(1);
 125         }
 126
 127         glCreateShaderObjectARB = (PFNGLCREATESHADEROBJECTARBPROC)
 128                 GETPROCADDRESS("glCreateShaderObjectARB");
 129         glShaderSourceARB = (PFNGLSHADERSOURCEARBPROC)
 130                 GETPROCADDRESS("glShaderSourceARB");
 131         glCompileShaderARB = (PFNGLCOMPILESHADERARBPROC)
 132                 GETPROCADDRESS("glCompileShaderARB");
 133         glCreateProgramObjectARB = (PFNGLCREATEPROGRAMOBJECTARBPROC)
 134                 GETPROCADDRESS("glCreateProgramObjectARB");
 135         glAttachObjectARB = (PFNGLATTACHOBJECTARBPROC)
 136                 GETPROCADDRESS("glAttachObjectARB");
 137         glLinkProgramARB = (PFNGLLINKPROGRAMARBPROC)
 138                 GETPROCADDRESS ("glLinkProgramARB");
 139         glUseProgramObjectARB = (PFNGLUSEPROGRAMOBJECTARBPROC)
 140                 GETPROCADDRESS("glUseProgramObjectARB");
 141
 142         glGetUniformLocationARB = (PFNGLGETUNIFORMLOCATIONARBPROC)
 143                 GETPROCADDRESS("glGetUniformLocationARB");
 144         glUniform1fARB = (PFNGLUNIFORM1FARBPROC)
 145                 GETPROCADDRESS("glUniform1fARB");
 146
 147         fragShader = glCreateShaderObjectARB (GL_FRAGMENT_SHADER_ARB);
 148         glShaderSourceARB (fragShader, 1, &fragShaderText, NULL);
 149         glCompileShaderARB (fragShader);
 150
 151         vertShader = glCreateShaderObjectARB (GL_VERTEX_SHADER_ARB);
 152         glShaderSourceARB (vertShader, 1, &vertShaderText, NULL);
 153         glCompileShaderARB (vertShader);
 154
 155         program = glCreateProgramObjectARB ();
 156         glAttachObjectARB (program, fragShader);
 157         glAttachObjectARB (program, vertShader);
 158         glLinkProgramARB (program);
 159         glUseProgramObjectARB (program);
 160
 161         uTime = glGetUniformLocationARB (program, "time");
 162
 163         glClearColor (0.0f, 0.1f, 0.3f, 1.0f);
 164         glEnable (GL_CULL_FACE);
 165         glEnable (GL_DEPTH_TEST);
 166
 167         printf ("GL_RENDERER = %s\n", (const char *) glGetString (GL_RENDERER));
 168 }
 169
 170 int main (int argc, char *argv[])
 171 {
 172         glutInit (&argc, argv);
 173         glutInitWindowPosition ( 0, 0);
 174         glutInitWindowSize (200, 200);
 175         glutInitDisplayMode (GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 176         glutCreateWindow (argv[0]);
 177         glutReshapeFunc (Reshape);
 178         glutKeyboardFunc (Key);
 179         glutDisplayFunc (Redisplay);
 180         glutIdleFunc (Idle);
 181         Init ();
 182         glutMainLoop ();
 183         return 0;
 184 }
 185