src/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/glew.h>
  12 #include "glut_wrap.h"
  13 #include "shaderutil.h"
  14
  15
  16 static const char *VertShaderText =
  17    "void main() {\n"
  18    "   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
  19    "   gl_TexCoord[0] = gl_MultiTexCoord0;\n"
  20    "}\n";
  21
  22 static const char *FragShaderText =
  23    "uniform vec4 Scale, Bias;\n"
  24    "uniform float Slice;\n"
  25    "void main()\n"
  26    "{\n"
  27    "   vec4 scale = vec4(5.0);\n"
  28    "   vec4 p;\n"
  29    "   p.xy = gl_TexCoord[0].xy;\n"
  30    "   p.z = Slice;\n"
  31    "   p.w = 0.0;\n"
  32    "   vec4 n = noise4(p * scale);\n"
  33    "   gl_FragColor = n * Scale + Bias;\n"
  34    "}\n";
  35
  36
  37 static struct uniform_info Uniforms[] = {
  38    { "Scale",    1, GL_FLOAT_VEC4, { 0.5, 0.4, 0.0, 0}, -1 },
  39    { "Bias",     1, GL_FLOAT_VEC4, { 0.5, 0.3, 0.0, 0}, -1 },
  40    { "Slice",    1, GL_FLOAT, { 0.5, 0, 0, 0}, -1 },
  41    END_OF_UNIFORMS
  42 };
  43
  44 /* program/shader objects */
  45 static GLuint fragShader;
  46 static GLuint vertShader;
  47 static GLuint program;
  48
  49 static GLint win = 0;
  50 static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f;
  51 static GLfloat Slice = 0.0;
  52 static GLboolean Anim = GL_FALSE;
  53
  54
  55 static void
  56 Idle(void)
  57 {
  58    Slice += 0.01;
  59    glutPostRedisplay();
  60 }
  61
  62
  63 static void
  64 Redisplay(void)
  65 {
  66    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  67
  68    glUniform1fv(Uniforms[2].location, 1, &Slice);
  69
  70    glPushMatrix();
  71    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
  72    glRotatef(yRot, 0.0f, 1.0f, 0.0f);
  73    glRotatef(zRot, 0.0f, 0.0f, 1.0f);
  74
  75    glBegin(GL_POLYGON);
  76    glTexCoord2f(0, 0);   glVertex2f(-2, -2);
  77    glTexCoord2f(1, 0);   glVertex2f( 2, -2);
  78    glTexCoord2f(1, 1);   glVertex2f( 2,  2);
  79    glTexCoord2f(0, 1);   glVertex2f(-2,  2);
  80    glEnd();
  81
  82    glPopMatrix();
  83
  84    glutSwapBuffers();
  85 }
  86
  87
  88 static void
  89 Reshape(int width, int height)
  90 {
  91    glViewport(0, 0, width, height);
  92    glMatrixMode(GL_PROJECTION);
  93    glLoadIdentity();
  94    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  95    glMatrixMode(GL_MODELVIEW);
  96    glLoadIdentity();
  97    glTranslatef(0.0f, 0.0f, -15.0f);
  98 }
  99
 100
 101 static void
 102 CleanUp(void)
 103 {
 104    glDeleteShader(fragShader);
 105    glDeleteShader(vertShader);
 106    glDeleteProgram(program);
 107    glutDestroyWindow(win);
 108 }
 109
 110
 111 static void
 112 Key(unsigned char key, int x, int y)
 113 {
 114    const GLfloat step = 0.01;
 115   (void) x;
 116   (void) y;
 117
 118    switch(key) {
 119    case 'a':
 120       Anim = !Anim;
 121       glutIdleFunc(Anim ? Idle : NULL);
 122       break;
 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    vertShader = CompileShaderText(GL_VERTEX_SHADER, VertShaderText);
 178    fragShader = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderText);
 179    program = LinkShaders(vertShader, fragShader);
 180
 181    glUseProgram(program);
 182
 183    SetUniformValues(program, Uniforms);
 184    PrintUniforms(Uniforms);
 185
 186    assert(glGetError() == 0);
 187
 188    glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
 189
 190    printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
 191
 192    assert(glIsProgram(program));
 193    assert(glIsShader(fragShader));
 194    assert(glIsShader(vertShader));
 195
 196    glColor3f(1, 0, 0);
 197 }
 198
 199
 200 int
 201 main(int argc, char *argv[])
 202 {
 203    glutInit(&argc, argv);
 204    glutInitWindowSize(400, 400);
 205    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 206    win = glutCreateWindow(argv[0]);
 207    glewInit();
 208    glutReshapeFunc(Reshape);
 209    glutKeyboardFunc(Key);
 210    glutSpecialFunc(SpecialKey);
 211    glutDisplayFunc(Redisplay);
 212    Init();
 213    glutMainLoop();
 214    return 0;
 215 }
 216