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