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/gl.h>
  13 #include <GL/glut.h>
  14 #include <GL/glext.h>
  15 #include "extfuncs.h"
  16 #include "shaderutil.h"
  17
  18
  19 static GLfloat diffuse[4] = { 0.5f, 1.0f, 0.5f, 1.0f };
  20 static GLfloat specular[4] = { 0.8f, 0.8f, 0.8f, 1.0f };
  21 static GLfloat lightPos[4] = { 0.0f, 10.0f, 20.0f, 0.0f };
  22 static GLfloat delta = 1.0f;
  23
  24 static GLuint VertShader1;
  25 static GLuint VertShader2;
  26 static GLuint FragShader1;
  27 static GLuint FragShader2;
  28 static GLuint Program;
  29
  30 static GLint uDiffuse;
  31 static GLint uSpecular;
  32 static GLint uTexture;
  33
  34 static GLint Win = 0;
  35 static GLboolean anim = GL_TRUE;
  36
  37
  38
  39 static const char *FragShaderSource1 =
  40    "float compute_dotprod(const vec3 normal) \n"
  41    "{ \n"
  42    "   float dotProd = max(dot(gl_LightSource[0].position.xyz, \n"
  43    "                           normalize(normal)), 0.0); \n"
  44    "   return dotProd; \n"
  45    "} \n";
  46
  47 static const char *FragShaderSource2 =
  48    "uniform vec4 diffuse;\n"
  49    "uniform vec4 specular;\n"
  50    "varying vec3 normal;\n"
  51    "\n"
  52    "// external function \n"
  53    "float compute_dotprod(const vec3 normal); \n"
  54    "\n"
  55    "void main() \n"
  56    "{ \n"
  57    "   float dotProd = compute_dotprod(normal); \n"
  58    "   gl_FragColor = diffuse * dotProd + specular * pow(dotProd, 20.0); \n"
  59    "} \n";
  60
  61
  62 static const char *VertShaderSource1 =
  63    "vec3 compute_normal() \n"
  64    "{ \n"
  65    "   return gl_NormalMatrix * gl_Normal; \n"
  66    "} \n";
  67
  68 static const char *VertShaderSource2 =
  69    "varying vec3 normal;\n"
  70    "\n"
  71    "// external function \n"
  72    "vec3 compute_normal(); \n"
  73    "\n"
  74    "void main() \n"
  75    "{ \n"
  76    "   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex; \n"
  77    "   normal = compute_normal(); \n"
  78    "} \n";
  79
  80
  81 static void
  82 normalize(GLfloat *dst, const GLfloat *src)
  83 {
  84    GLfloat len = sqrt(src[0] * src[0] + src[1] * src[1] + src[2] * src[2]);
  85    dst[0] = src[0] / len;
  86    dst[1] = src[1] / len;
  87    dst[2] = src[2] / len;
  88    dst[3] = src[3];
  89 }
  90
  91
  92 static void
  93 Redisplay(void)
  94 {
  95    GLfloat vec[4];
  96
  97    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  98
  99    /* update light position */
 100    normalize(vec, lightPos);
 101    glLightfv(GL_LIGHT0, GL_POSITION, vec);
 102
 103    glutSolidSphere(2.0, 10, 5);
 104
 105    glutSwapBuffers();
 106 }
 107
 108
 109 static void
 110 Idle(void)
 111 {
 112    lightPos[0] += delta;
 113    if (lightPos[0] > 25.0f || lightPos[0] < -25.0f)
 114       delta = -delta;
 115    glutPostRedisplay();
 116 }
 117
 118
 119 static void
 120 Reshape(int width, int height)
 121 {
 122    glViewport(0, 0, width, height);
 123    glMatrixMode(GL_PROJECTION);
 124    glLoadIdentity();
 125    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
 126    glMatrixMode(GL_MODELVIEW);
 127    glLoadIdentity();
 128    glTranslatef(0.0f, 0.0f, -15.0f);
 129 }
 130
 131
 132 static void
 133 CleanUp(void)
 134 {
 135    glDeleteShader_func(VertShader1);
 136    glDeleteShader_func(VertShader2);
 137    glDeleteShader_func(FragShader1);
 138    glDeleteShader_func(FragShader2);
 139    glDeleteProgram_func(Program);
 140    glutDestroyWindow(Win);
 141 }
 142
 143
 144 static void
 145 Key(unsigned char key, int x, int y)
 146 {
 147   (void) x;
 148   (void) y;
 149
 150    switch(key) {
 151    case ' ':
 152    case 'a':
 153       anim = !anim;
 154       if (anim)
 155          glutIdleFunc(Idle);
 156       else
 157          glutIdleFunc(NULL);
 158       break;
 159    case 'x':
 160       lightPos[0] -= 1.0f;
 161       break;
 162    case 'X':
 163       lightPos[0] += 1.0f;
 164       break;
 165    case 27:
 166       CleanUp();
 167       exit(0);
 168       break;
 169    }
 170    glutPostRedisplay();
 171 }
 172
 173
 174 static void
 175 CheckLink(GLuint prog)
 176 {
 177    GLint stat;
 178    glGetProgramiv_func(prog, GL_LINK_STATUS, &stat);
 179    if (!stat) {
 180       GLchar log[1000];
 181       GLsizei len;
 182       glGetProgramInfoLog_func(prog, 1000, &len, log);
 183       fprintf(stderr, "Linker error:\n%s\n", log);
 184    }
 185 }
 186
 187
 188 static void
 189 Init(void)
 190 {
 191    if (!ShadersSupported())
 192       exit(1);
 193
 194    GetExtensionFuncs();
 195
 196    printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
 197
 198    VertShader1 = CompileShaderText(GL_VERTEX_SHADER, VertShaderSource1);
 199    VertShader2 = CompileShaderText(GL_VERTEX_SHADER, VertShaderSource2);
 200    FragShader1 = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderSource1);
 201    FragShader2 = CompileShaderText(GL_FRAGMENT_SHADER, FragShaderSource2);
 202
 203    Program = glCreateProgram_func();
 204    glAttachShader_func(Program, VertShader1);
 205    glAttachShader_func(Program, VertShader2);
 206    glAttachShader_func(Program, FragShader1);
 207    glAttachShader_func(Program, FragShader2);
 208
 209    glLinkProgram_func(Program);
 210
 211    CheckLink(Program);
 212
 213    glUseProgram_func(Program);
 214
 215    uDiffuse = glGetUniformLocation_func(Program, "diffuse");
 216    uSpecular = glGetUniformLocation_func(Program, "specular");
 217    uTexture = glGetUniformLocation_func(Program, "texture");
 218    printf("DiffusePos %d  SpecularPos %d  TexturePos %d\n",
 219           uDiffuse, uSpecular, uTexture);
 220
 221    glUniform4fv_func(uDiffuse, 1, diffuse);
 222    glUniform4fv_func(uSpecular, 1, specular);
 223
 224    glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
 225    glEnable(GL_DEPTH_TEST);
 226
 227    glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, diffuse);
 228    glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
 229    glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 10.0f);
 230
 231    assert(glIsProgram_func(Program));
 232    assert(glIsShader_func(VertShader1));
 233    assert(glIsShader_func(VertShader2));
 234    assert(glIsShader_func(FragShader1));
 235    assert(glIsShader_func(FragShader2));
 236
 237    glColor3f(1, 0, 0);
 238 }
 239
 240
 241 int
 242 main(int argc, char *argv[])
 243 {
 244    glutInit(&argc, argv);
 245    glutInitWindowPosition( 0, 0);
 246    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 247    Win = glutCreateWindow(argv[0]);
 248    glutReshapeFunc(Reshape);
 249    glutKeyboardFunc(Key);
 250    glutDisplayFunc(Redisplay);
 251    if (anim)
 252       glutIdleFunc(Idle);
 253    Init();
 254    glutMainLoop();
 255    return 0;
 256 }
 257
 258