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