progs/glsl/linktest.c

   1 /**
   2  * Test linking of multiple compilation units.
   3  * Brian Paul
   4  * 28 March 2009
   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/glut.h>
  14 #include "shaderutil.h"
  15
  16
  17 static GLfloat diffuse[4] = { 0.5f, 1.0f, 0.5f, 1.0f };
  18 static GLfloat specular[4] = { 0.8f, 0.8f, 0.8f, 1.0f };
  19 static GLfloat lightPos[4] = { 0.0f, 10.0f, 20.0f, 0.0f };
  20 static GLfloat delta = 1.0f;
  21
  22 static GLuint VertShader1;
  23 static GLuint VertShader2;
  24 static GLuint FragShader1;
  25 static GLuint FragShader2;
  26 static GLuint Program;
  27
  28 static GLint uDiffuse;
  29 static GLint uSpecular;
  30 static GLint uTexture;
  31
  32 static GLint Win = 0;
  33 static GLboolean anim = GL_TRUE;
  34
  35
  36
  37 static const char *FragShaderSource1 =
  38    "float compute_dotprod(const vec3 normal) \n"
  39    "{ \n"
  40    "   float dotProd = max(dot(gl_LightSource[0].position.xyz, \n"
  41    "                           normalize(normal)), 0.0); \n"
  42    "   return dotProd; \n"
  43    "} \n";
  44
  45 static const char *FragShaderSource2 =
  46    "uniform vec4 diffuse;\n"
  47    "uniform vec4 specular;\n"
  48    "varying vec3 normal;\n"
  49    "\n"
  50    "// external function \n"
  51    "float compute_dotprod(const vec3 normal); \n"
  52    "\n"
  53    "void main() \n"
  54    "{ \n"
  55    "   float dotProd = compute_dotprod(normal); \n"
  56    "   gl_FragColor = diffuse * dotProd + specular * pow(dotProd, 20.0); \n"
  57    "} \n";
  58
  59
  60 static const char *VertShaderSource1 =
  61    "vec3 compute_normal() \n"
  62    "{ \n"
  63    "   return gl_NormalMatrix * gl_Normal; \n"
  64    "} \n";
  65
  66 static const char *VertShaderSource2 =
  67    "varying vec3 normal;\n"
  68    "\n"
  69    "// external function \n"
  70    "vec3 compute_normal(); \n"
  71    "\n"
  72    "void main() \n"
  73    "{ \n"
  74    "   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; \n"
  75    "   normal = compute_normal(); \n"
  76    "} \n";
  77
  78
  79 static void
  80 normalize(GLfloat *dst, const GLfloat *src)
  81 {
  82    GLfloat len = sqrt(src[0] * src[0] + src[1] * src[1] + src[2] * src[2]);
  83    dst[0] = src[0] / len;
  84    dst[1] = src[1] / len;
  85    dst[2] = src[2] / len;
  86    dst[3] = src[3];
  87 }
  88
  89
  90 static void
  91 Redisplay(void)
  92 {
  93    GLfloat vec[4];
  94
  95    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  96
  97    /* update light position */
  98    normalize(vec, lightPos);
  99    glLightfv(GL_LIGHT0, GL_POSITION, vec);
 100
 101    glutSolidSphere(2.0, 10, 5);
 102
 103    glutSwapBuffers();
 104 }
 105
 106
 107 static void
 108 Idle(void)
 109 {
 110    lightPos[0] += delta;
 111    if (lightPos[0] > 25.0f || lightPos[0] < -25.0f)
 112       delta = -delta;
 113    glutPostRedisplay();
 114 }
 115
 116
 117 static void
 118 Reshape(int width, int height)
 119 {
 120    glViewport(0, 0, width, height);
 121    glMatrixMode(GL_PROJECTION);
 122    glLoadIdentity();
 123    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
 124    glMatrixMode(GL_MODELVIEW);
 125    glLoadIdentity();
 126    glTranslatef(0.0f, 0.0f, -15.0f);
 127 }
 128
 129
 130 static void
 131 CleanUp(void)
 132 {
 133    glDeleteShader(VertShader1);
 134    glDeleteShader(VertShader2);
 135    glDeleteShader(FragShader1);
 136    glDeleteShader(FragShader2);
 137    glDeleteProgram(Program);
 138    glutDestroyWindow(Win);
 139 }
 140
 141
 142 static void
 143 Key(unsigned char key, int x, int y)
 144 {
 145   (void) x;
 146   (void) y;
 147
 148    switch(key) {
 149    case ' ':
 150    case 'a':
 151       anim = !anim;
 152       if (anim)
 153          glutIdleFunc(Idle);
 154       else
 155          glutIdleFunc(NULL);
 156       break;
 157    case 'x':
 158       lightPos[0] -= 1.0f;
 159       break;
 160    case 'X':
 161       lightPos[0] += 1.0f;
 162       break;
 163    case 27:
 164       CleanUp();
 165       exit(0);
 166       break;
 167    }
 168    glutPostRedisplay();
 169 }
 170
 171
 172 static void
 173 CheckLink(GLuint prog)
 174 {
 175    GLint stat;
 176    glGetProgramiv(prog, GL_LINK_STATUS, &stat);
 177    if (!stat) {
 178       GLchar log[1000];
 179       GLsizei len;
 180       glGetProgramInfoLog(prog, 1000, &len, log);
 181       fprintf(stderr, "Linker error:\n%s\n", log);
 182    }
 183 }
 184
 185
 186 static void
 187 Init(void)
 188 {
 189    if (!ShadersSupported())
 190       exit(1);
 191
 192    printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
 193
 194    VertShader1 = CompileShaderText(GL_VERTEX_SHADER, VertShaderSource1);
 195    VertShader2 = CompileShaderText(GL_VERTEX_SHADER, VertShaderSource2);
 196    FragShader1 = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderSource1);
 197    FragShader2 = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderSource2);
 198
 199    Program = glCreateProgram();
 200    glAttachShader(Program, VertShader1);
 201    glAttachShader(Program, VertShader2);
 202    glAttachShader(Program, FragShader1);
 203    glAttachShader(Program, FragShader2);
 204
 205    glLinkProgram(Program);
 206
 207    CheckLink(Program);
 208
 209    glUseProgram(Program);
 210
 211    uDiffuse = glGetUniformLocation(Program, "diffuse");
 212    uSpecular = glGetUniformLocation(Program, "specular");
 213    uTexture = glGetUniformLocation(Program, "texture");
 214    printf("DiffusePos %d  SpecularPos %d  TexturePos %d\n",
 215           uDiffuse, uSpecular, uTexture);
 216
 217    glUniform4fv(uDiffuse, 1, diffuse);
 218    glUniform4fv(uSpecular, 1, specular);
 219
 220    glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
 221    glEnable(GL_DEPTH_TEST);
 222
 223    glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, diffuse);
 224    glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
 225    glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 10.0f);
 226
 227    assert(glIsProgram(Program));
 228    assert(glIsShader(VertShader1));
 229    assert(glIsShader(VertShader2));
 230    assert(glIsShader(FragShader1));
 231    assert(glIsShader(FragShader2));
 232
 233    glColor3f(1, 0, 0);
 234 }
 235
 236
 237 int
 238 main(int argc, char *argv[])
 239 {
 240    glutInit(&argc, argv);
 241    glutInitWindowSize(300, 300);
 242    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 243    Win = glutCreateWindow(argv[0]);
 244    glewInit();
 245    glutReshapeFunc(Reshape);
 246    glutKeyboardFunc(Key);
 247    glutDisplayFunc(Redisplay);
 248    if (anim)
 249       glutIdleFunc(Idle);
 250    Init();
 251    glutMainLoop();
 252    return 0;
 253 }
 254
 255