src/glsl/toyball.c

   1 /**
   2  * "Toy Ball" shader demo.  Uses the example shaders from
   3  * chapter 11 of the OpenGL Shading Language "orange" book.
   4  * 16 Jan 2007
   5  */
   6
   7 #include <assert.h>
   8 #include <string.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <math.h>
  12 #include <GL/glew.h>
  13 #include "glut_wrap.h"
  14 #include "shaderutil.h"
  15
  16
  17 static char *FragProgFile = "CH11-toyball.frag";
  18 static char *VertProgFile = "CH11-toyball.vert";
  19
  20 /* program/shader objects */
  21 static GLuint fragShader;
  22 static GLuint vertShader;
  23 static GLuint program;
  24
  25
  26 static struct uniform_info Uniforms[] = {
  27    { "LightDir",    1, GL_FLOAT_VEC4, { 0.57737, 0.57735, 0.57735, 0.0 }, -1 },
  28    { "HVector",     1, GL_FLOAT_VEC4, { 0.32506, 0.32506, 0.88808, 0.0 }, -1 },
  29    { "BallCenter",  1, GL_FLOAT_VEC4, { 0.0, 0.0, 0.0, 1.0 }, -1 },
  30    { "SpecularColor", 1, GL_FLOAT_VEC4, { 0.4, 0.4, 0.4, 60.0 }, -1 },
  31    { "Red",         1, GL_FLOAT_VEC4, { 0.6, 0.0, 0.0, 1.0 }, -1 },
  32    { "Blue",        1, GL_FLOAT_VEC4, { 0.0, 0.3, 0.6, 1.0 }, -1 },
  33    { "Yellow",      1, GL_FLOAT_VEC4, { 0.6, 0.5, 0.0, 1.0 }, -1 },
  34    { "HalfSpace0",  1, GL_FLOAT_VEC4, { 1.0, 0.0, 0.0, 0.2 }, -1 },
  35    { "HalfSpace1",  1, GL_FLOAT_VEC4, { 0.309016994, 0.951056516, 0.0, 0.2 }, -1 },
  36    { "HalfSpace2",  1, GL_FLOAT_VEC4, { -0.809016994, 0.587785252, 0.0, 0.2 }, -1 },
  37    { "HalfSpace3",  1, GL_FLOAT_VEC4, { -0.809016994, -0.587785252, 0.0, 0.2 }, -1 },
  38    { "HalfSpace4",  1, GL_FLOAT_VEC4, { 0.309116994, -0.951056516, 0.0, 0.2 }, -1 },
  39    { "InOrOutInit", 1, GL_FLOAT, { -3.0, 0, 0, 0 }, -1 },
  40    { "StripeWidth", 1, GL_FLOAT, {  0.3, 0, 0, 0 }, -1 },
  41    { "FWidth",      1, GL_FLOAT, { 0.005, 0, 0, 0 }, -1 },
  42    END_OF_UNIFORMS
  43 };
  44
  45 static GLint win = 0;
  46 static GLboolean Anim = GL_FALSE;
  47 static GLfloat TexRot = 0.0;
  48 static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f;
  49
  50
  51 static void
  52 Idle(void)
  53 {
  54    TexRot += 2.0;
  55    if (TexRot > 360.0)
  56       TexRot -= 360.0;
  57    glutPostRedisplay();
  58 }
  59
  60
  61 static void
  62 Redisplay(void)
  63 {
  64    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  65
  66    glPushMatrix();
  67    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
  68    glRotatef(yRot, 0.0f, 1.0f, 0.0f);
  69    glRotatef(zRot, 0.0f, 0.0f, 1.0f);
  70
  71    glMatrixMode(GL_TEXTURE);
  72    glLoadIdentity();
  73    glRotatef(TexRot, 0.0f, 1.0f, 0.0f);
  74    glMatrixMode(GL_MODELVIEW);
  75
  76    glutSolidSphere(2.0, 20, 10);
  77
  78    glPopMatrix();
  79
  80    glutSwapBuffers();
  81 }
  82
  83
  84 static void
  85 Reshape(int width, int height)
  86 {
  87    glViewport(0, 0, width, height);
  88    glMatrixMode(GL_PROJECTION);
  89    glLoadIdentity();
  90    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  91    glMatrixMode(GL_MODELVIEW);
  92    glLoadIdentity();
  93    glTranslatef(0.0f, 0.0f, -15.0f);
  94 }
  95
  96
  97 static void
  98 CleanUp(void)
  99 {
 100    glDeleteShader(fragShader);
 101    glDeleteShader(vertShader);
 102    glDeleteProgram(program);
 103    glutDestroyWindow(win);
 104 }
 105
 106
 107 static void
 108 Key(unsigned char key, int x, int y)
 109 {
 110    const GLfloat step = 2.0;
 111   (void) x;
 112   (void) y;
 113
 114    switch(key) {
 115    case 'a':
 116       Anim = !Anim;
 117       if (Anim)
 118          glutIdleFunc(Idle);
 119       else
 120          glutIdleFunc(NULL);
 121       break;
 122    case 'z':
 123       zRot += step;
 124       break;
 125    case 'Z':
 126       zRot -= step;
 127       break;
 128    case 27:
 129       CleanUp();
 130       exit(0);
 131       break;
 132    }
 133    glutPostRedisplay();
 134 }
 135
 136
 137 static void
 138 SpecialKey(int key, int x, int y)
 139 {
 140    const GLfloat step = 2.0;
 141
 142   (void) x;
 143   (void) y;
 144
 145    switch(key) {
 146    case GLUT_KEY_UP:
 147       xRot += step;
 148       break;
 149    case GLUT_KEY_DOWN:
 150       xRot -= step;
 151       break;
 152    case GLUT_KEY_LEFT:
 153       yRot -= step;
 154       break;
 155    case GLUT_KEY_RIGHT:
 156       yRot += step;
 157       break;
 158    }
 159    glutPostRedisplay();
 160 }
 161
 162
 163
 164 static void
 165 Init(void)
 166 {
 167    if (!ShadersSupported())
 168       exit(1);
 169
 170    vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile);
 171    fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile);
 172    program = LinkShaders(vertShader, fragShader);
 173
 174    glUseProgram(program);
 175
 176    SetUniformValues(program, Uniforms);
 177    PrintUniforms(Uniforms);
 178
 179    assert(glGetError() == 0);
 180
 181    glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
 182
 183    glEnable(GL_DEPTH_TEST);
 184
 185    glColor3f(1, 0, 0);
 186 }
 187
 188
 189 static void
 190 ParseOptions(int argc, char *argv[])
 191 {
 192    int i;
 193    for (i = 1; i < argc; i++) {
 194       if (strcmp(argv[i], "-fs") == 0) {
 195          FragProgFile = argv[i+1];
 196       }
 197       else if (strcmp(argv[i], "-vs") == 0) {
 198          VertProgFile = argv[i+1];
 199       }
 200    }
 201 }
 202
 203
 204 int
 205 main(int argc, char *argv[])
 206 {
 207    glutInit(&argc, argv);
 208    glutInitWindowSize(400, 400);
 209    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 210    win = glutCreateWindow(argv[0]);
 211    glewInit();
 212    glutReshapeFunc(Reshape);
 213    glutKeyboardFunc(Key);
 214    glutSpecialFunc(SpecialKey);
 215    glutDisplayFunc(Redisplay);
 216    ParseOptions(argc, argv);
 217    Init();
 218    glutMainLoop();
 219    return 0;
 220 }
 221