progs/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/gl.h>
  13 #include <GL/glut.h>
  14 #include <GL/glext.h>
  15 #include "extfuncs.h"
  16 #include "shaderutil.h"
  17
  18
  19 static char *FragProgFile = "CH11-toyball.frag";
  20 static char *VertProgFile = "CH11-toyball.vert";
  21
  22 /* program/shader objects */
  23 static GLuint fragShader;
  24 static GLuint vertShader;
  25 static GLuint program;
  26
  27
  28 static struct uniform_info Uniforms[] = {
  29    { "LightDir",       4, GL_FLOAT, { 0.57737, 0.57735, 0.57735, 0.0 }, -1 },
  30    { "HVector",        4, GL_FLOAT, { 0.32506, 0.32506, 0.88808, 0.0 }, -1 },
  31    { "BallCenter",     4, GL_FLOAT, { 0.0, 0.0, 0.0, 1.0 }, -1 },
  32    { "SpecularColor",  4, GL_FLOAT, { 0.4, 0.4, 0.4, 60.0 }, -1 },
  33    { "Red",         4, GL_FLOAT, { 0.6, 0.0, 0.0, 1.0 }, -1 },
  34    { "Blue",        4, GL_FLOAT, { 0.0, 0.3, 0.6, 1.0 }, -1 },
  35    { "Yellow",      4, GL_FLOAT, { 0.6, 0.5, 0.0, 1.0 }, -1 },
  36    { "HalfSpace0",  4, GL_FLOAT, { 1.0, 0.0, 0.0, 0.2 }, -1 },
  37    { "HalfSpace1",  4, GL_FLOAT, { 0.309016994, 0.951056516, 0.0, 0.2 }, -1 },
  38    { "HalfSpace2",  4, GL_FLOAT, { -0.809016994, 0.587785252, 0.0, 0.2 }, -1 },
  39    { "HalfSpace3",  4, GL_FLOAT, { -0.809016994, -0.587785252, 0.0, 0.2 }, -1 },
  40    { "HalfSpace4",  4, GL_FLOAT, { 0.309116994, -0.951056516, 0.0, 0.2 }, -1 },
  41    { "InOrOutInit", 1, GL_FLOAT, { -3.0, 0, 0, 0 }, -1 },
  42    { "StripeWidth", 1, GL_FLOAT, {  0.3, 0, 0, 0 }, -1 },
  43    { "FWidth",      1, GL_FLOAT, { 0.005, 0, 0, 0 }, -1 },
  44    END_OF_UNIFORMS
  45 };
  46
  47 static GLint win = 0;
  48 static GLboolean Anim = GL_FALSE;
  49 static GLfloat TexRot = 0.0;
  50 static GLfloat xRot = 0.0f, yRot = 0.0f, zRot = 0.0f;
  51
  52
  53 static void
  54 Idle(void)
  55 {
  56    TexRot += 2.0;
  57    if (TexRot > 360.0)
  58       TexRot -= 360.0;
  59    glutPostRedisplay();
  60 }
  61
  62
  63 static void
  64 Redisplay(void)
  65 {
  66    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  67
  68    glPushMatrix();
  69    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
  70    glRotatef(yRot, 0.0f, 1.0f, 0.0f);
  71    glRotatef(zRot, 0.0f, 0.0f, 1.0f);
  72
  73    glMatrixMode(GL_TEXTURE);
  74    glLoadIdentity();
  75    glRotatef(TexRot, 0.0f, 1.0f, 0.0f);
  76    glMatrixMode(GL_MODELVIEW);
  77
  78    glutSolidSphere(2.0, 20, 10);
  79
  80    glPopMatrix();
  81
  82    glutSwapBuffers();
  83 }
  84
  85
  86 static void
  87 Reshape(int width, int height)
  88 {
  89    glViewport(0, 0, width, height);
  90    glMatrixMode(GL_PROJECTION);
  91    glLoadIdentity();
  92    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
  93    glMatrixMode(GL_MODELVIEW);
  94    glLoadIdentity();
  95    glTranslatef(0.0f, 0.0f, -15.0f);
  96 }
  97
  98
  99 static void
 100 CleanUp(void)
 101 {
 102    glDeleteShader_func(fragShader);
 103    glDeleteShader_func(vertShader);
 104    glDeleteProgram_func(program);
 105    glutDestroyWindow(win);
 106 }
 107
 108
 109 static void
 110 Key(unsigned char key, int x, int y)
 111 {
 112    const GLfloat step = 2.0;
 113   (void) x;
 114   (void) y;
 115
 116    switch(key) {
 117    case 'a':
 118       Anim = !Anim;
 119       if (Anim)
 120          glutIdleFunc(Idle);
 121       else
 122          glutIdleFunc(NULL);
 123       break;
 124    case 'z':
 125       zRot += step;
 126       break;
 127    case 'Z':
 128       zRot -= step;
 129       break;
 130    case 27:
 131       CleanUp();
 132       exit(0);
 133       break;
 134    }
 135    glutPostRedisplay();
 136 }
 137
 138
 139 static void
 140 SpecialKey(int key, int x, int y)
 141 {
 142    const GLfloat step = 2.0;
 143
 144   (void) x;
 145   (void) y;
 146
 147    switch(key) {
 148    case GLUT_KEY_UP:
 149       xRot += step;
 150       break;
 151    case GLUT_KEY_DOWN:
 152       xRot -= step;
 153       break;
 154    case GLUT_KEY_LEFT:
 155       yRot -= step;
 156       break;
 157    case GLUT_KEY_RIGHT:
 158       yRot += step;
 159       break;
 160    }
 161    glutPostRedisplay();
 162 }
 163
 164
 165
 166 static void
 167 Init(void)
 168 {
 169    if (!ShadersSupported())
 170       exit(1);
 171
 172    GetExtensionFuncs();
 173
 174    vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile);
 175    fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile);
 176    program = LinkShaders(vertShader, fragShader);
 177
 178    glUseProgram_func(program);
 179
 180    InitUniforms(program, Uniforms);
 181
 182    assert(glGetError() == 0);
 183
 184    glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
 185
 186    glEnable(GL_DEPTH_TEST);
 187
 188    glColor3f(1, 0, 0);
 189 }
 190
 191
 192 static void
 193 ParseOptions(int argc, char *argv[])
 194 {
 195    int i;
 196    for (i = 1; i < argc; i++) {
 197       if (strcmp(argv[i], "-fs") == 0) {
 198          FragProgFile = argv[i+1];
 199       }
 200       else if (strcmp(argv[i], "-vs") == 0) {
 201          VertProgFile = argv[i+1];
 202       }
 203    }
 204 }
 205
 206
 207 int
 208 main(int argc, char *argv[])
 209 {
 210    glutInit(&argc, argv);
 211    glutInitWindowPosition( 0, 0);
 212    glutInitWindowSize(400, 400);
 213    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 214    win = glutCreateWindow(argv[0]);
 215    glutReshapeFunc(Reshape);
 216    glutKeyboardFunc(Key);
 217    glutSpecialFunc(SpecialKey);
 218    glutDisplayFunc(Redisplay);
 219    ParseOptions(argc, argv);
 220    Init();
 221    glutMainLoop();
 222    return 0;
 223 }
 224