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.txt";
  20 static char *VertProgFile = "CH11-toyball.vert.txt";
  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    glFinish();
  83    glFlush();
  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_func(fragShader);
 105    glDeleteShader_func(vertShader);
 106    glDeleteProgram_func(program);
 107    glutDestroyWindow(win);
 108 }
 109
 110
 111 static void
 112 Key(unsigned char key, int x, int y)
 113 {
 114    const GLfloat step = 2.0;
 115   (void) x;
 116   (void) y;
 117
 118    switch(key) {
 119    case 'a':
 120       Anim = !Anim;
 121       if (Anim)
 122          glutIdleFunc(Idle);
 123       else
 124          glutIdleFunc(NULL);
 125       break;
 126    case 'z':
 127       zRot += step;
 128       break;
 129    case 'Z':
 130       zRot -= step;
 131       break;
 132    case 27:
 133       CleanUp();
 134       exit(0);
 135       break;
 136    }
 137    glutPostRedisplay();
 138 }
 139
 140
 141 static void
 142 SpecialKey(int key, int x, int y)
 143 {
 144    const GLfloat step = 2.0;
 145
 146   (void) x;
 147   (void) y;
 148
 149    switch(key) {
 150    case GLUT_KEY_UP:
 151       xRot += step;
 152       break;
 153    case GLUT_KEY_DOWN:
 154       xRot -= step;
 155       break;
 156    case GLUT_KEY_LEFT:
 157       yRot -= step;
 158       break;
 159    case GLUT_KEY_RIGHT:
 160       yRot += step;
 161       break;
 162    }
 163    glutPostRedisplay();
 164 }
 165
 166
 167
 168 static void
 169 Init(void)
 170 {
 171    if (!ShadersSupported())
 172       exit(1);
 173
 174    GetExtensionFuncs();
 175
 176    vertShader = CompileShaderFile(GL_VERTEX_SHADER, VertProgFile);
 177    fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, FragProgFile);
 178    program = LinkShaders(vertShader, fragShader);
 179
 180    glUseProgram_func(program);
 181
 182    InitUniforms(program, Uniforms);
 183
 184    assert(glGetError() == 0);
 185
 186    glClearColor(0.4f, 0.4f, 0.8f, 0.0f);
 187
 188    glEnable(GL_DEPTH_TEST);
 189
 190    glColor3f(1, 0, 0);
 191 }
 192
 193
 194 static void
 195 ParseOptions(int argc, char *argv[])
 196 {
 197    int i;
 198    for (i = 1; i < argc; i++) {
 199       if (strcmp(argv[i], "-fs") == 0) {
 200          FragProgFile = argv[i+1];
 201       }
 202       else if (strcmp(argv[i], "-vs") == 0) {
 203          VertProgFile = argv[i+1];
 204       }
 205    }
 206 }
 207
 208
 209 int
 210 main(int argc, char *argv[])
 211 {
 212    glutInit(&argc, argv);
 213    glutInitWindowPosition( 0, 0);
 214    glutInitWindowSize(400, 400);
 215    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 216    win = glutCreateWindow(argv[0]);
 217    glutReshapeFunc(Reshape);
 218    glutKeyboardFunc(Key);
 219    glutSpecialFunc(SpecialKey);
 220    glutDisplayFunc(Redisplay);
 221    ParseOptions(argc, argv);
 222    Init();
 223    glutMainLoop();
 224    return 0;
 225 }
 226