progs/glsl/noise.c

   1 /**
   2  * Test noise() functions.
   3  * 28 Jan 2007
   4  */
   5
   6 #include <assert.h>
   7 #include <string.h>
   8 #include <stdio.h>
   9 #include <stdlib.h>
  10 #include <math.h>
  11 #include <GL/gl.h>
  12 #include <GL/glut.h>
  13 #include <GL/glext.h>
  14 #include "extfuncs.h"
  15 #include "shaderutil.h"
  16
  17
  18 static const char *VertShaderText =
  19    "void main() {\n"
  20    "   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
  21    "   gl_TexCoord[0] = gl_MultiTexCoord0;\n"
  22    "}\n";
  23
  24 static const char *FragShaderText =
  25    "uniform vec4 Scale, Bias;\n"
  26    "uniform float Slice;\n"
  27    "void main()\n"
  28    "{\n"
  29    "   vec4 scale = vec4(5.0);\n"
  30    "   vec4 p;\n"
  31    "   p.xy = gl_TexCoord[0].xy;\n"
  32    "   p.z = Slice;\n"
  33    "   p.w = 0;\n"
  34    "   vec4 n = noise4(p * scale);\n"
  35    "   gl_FragColor = n * Scale + Bias;\n"
  36    "}\n";
  37
  38
  39 static struct uniform_info Uniforms[] = {
  40    { "Scale",    4, GL_FLOAT, { 0.5, 0.4, 0.0, 0}, -1 },
  41    { "Bias",     4, GL_FLOAT, { 0.5, 0.3, 0.0, 0}, -1 },
  42    { "Slice",    1, GL_FLOAT, { 0.5, 0, 0, 0}, -1 },
  43    END_OF_UNIFORMS
  44 };
  45
  46 /* program/shader objects */
  47 static GLuint fragShader;
  48 static GLuint vertShader;
  49 static GLuint program;
  50
  51 static GLint win = 0;
  52 static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f;
  53 static GLfloat Slice = 0.0;
  54 static GLboolean Anim = GL_FALSE;
  55
  56
  57 static void
  58 Idle(void)
  59 {
  60    Slice += 0.01;
  61    glutPostRedisplay();
  62 }
  63
  64
  65 static void
  66 Redisplay(void)
  67 {
  68    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  69
  70    glUniform1fv_func(Uniforms[2].location, 1, &Slice);
  71
  72    glPushMatrix();
  73    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
  74    glRotatef(yRot, 0.0f, 1.0f, 0.0f);
  75    glRotatef(zRot, 0.0f, 0.0f, 1.0f);
  76
  77    glBegin(GL_POLYGON);
  78    glTexCoord2f(0, 0);   glVertex2f(-2, -2);
  79    glTexCoord2f(1, 0);   glVertex2f( 2, -2);
  80    glTexCoord2f(1, 1);   glVertex2f( 2,  2);
  81    glTexCoord2f(0, 1);   glVertex2f(-2,  2);
  82    glEnd();
  83
  84    glPopMatrix();
  85
  86    glutSwapBuffers();
  87 }
  88
  89
  90 static void
  91 Reshape(int width, int height)
  92 {
  93    glViewport(0, 0, width, height);
  94    glMatrixMode(GL_PROJECTION);
  95    glLoadIdentity();
  96    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  97    glMatrixMode(GL_MODELVIEW);
  98    glLoadIdentity();
  99    glTranslatef(0.0f, 0.0f, -15.0f);
 100 }
 101
 102
 103 static void
 104 CleanUp(void)
 105 {
 106    glDeleteShader_func(fragShader);
 107    glDeleteShader_func(vertShader);
 108    glDeleteProgram_func(program);
 109    glutDestroyWindow(win);
 110 }
 111
 112
 113 static void
 114 Key(unsigned char key, int x, int y)
 115 {
 116    const GLfloat step = 0.01;
 117   (void) x;
 118   (void) y;
 119
 120    switch(key) {
 121    case 'a':
 122       Anim = !Anim;
 123       glutIdleFunc(Anim ? Idle : NULL);
 124    case 's':
 125       Slice -= step;
 126       break;
 127    case 'S':
 128       Slice += step;
 129       break;
 130    case 'z':
 131       zRot -= 1.0;
 132       break;
 133    case 'Z':
 134       zRot += 1.0;
 135       break;
 136    case 27:
 137       CleanUp();
 138       exit(0);
 139       break;
 140    }
 141    glutPostRedisplay();
 142 }
 143
 144
 145 static void
 146 SpecialKey(int key, int x, int y)
 147 {
 148    const GLfloat step = 3.0f;
 149
 150   (void) x;
 151   (void) y;
 152
 153    switch(key) {
 154    case GLUT_KEY_UP:
 155       xRot -= step;
 156       break;
 157    case GLUT_KEY_DOWN:
 158       xRot += step;
 159       break;
 160    case GLUT_KEY_LEFT:
 161       yRot -= step;
 162       break;
 163    case GLUT_KEY_RIGHT:
 164       yRot += step;
 165       break;
 166    }
 167    glutPostRedisplay();
 168 }
 169
 170
 171
 172 static void
 173 Init(void)
 174 {
 175    if (!ShadersSupported())
 176       exit(1);
 177
 178    GetExtensionFuncs();
 179
 180    vertShader = CompileShaderText(GL_VERTEX_SHADER, VertShaderText);
 181    fragShader = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderText);
 182    program = LinkShaders(vertShader, fragShader);
 183
 184    glUseProgram_func(program);
 185
 186    InitUniforms(program, Uniforms);
 187
 188    assert(glGetError() == 0);
 189
 190    glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
 191
 192    printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
 193
 194    assert(glIsProgram_func(program));
 195    assert(glIsShader_func(fragShader));
 196    assert(glIsShader_func(vertShader));
 197
 198    glColor3f(1, 0, 0);
 199 }
 200
 201
 202 int
 203 main(int argc, char *argv[])
 204 {
 205    glutInit(&argc, argv);
 206    glutInitWindowPosition( 0, 0);
 207    glutInitWindowSize(400, 400);
 208    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 209    win = glutCreateWindow(argv[0]);
 210    glutReshapeFunc(Reshape);
 211    glutKeyboardFunc(Key);
 212    glutSpecialFunc(SpecialKey);
 213    glutDisplayFunc(Redisplay);
 214    Init();
 215    glutMainLoop();
 216    return 0;
 217 }
 218