Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 1 | /* |
| 2 | * Use GL_ARB_fragment_shader and GL_ARB_vertex_shader to implement |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 3 | * simple per-pixel lighting. |
| 4 | * |
| 5 | * Michal Krol |
Michal Krol | cc15916 | 2006-02-21 12:35:06 +0000 | [diff] [blame] | 6 | * 20 February 2006 |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 7 | * |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 8 | * Based on the original demo by: |
| 9 | * Brian Paul |
| 10 | * 17 April 2003 |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 11 | */ |
| 12 | |
| 13 | #ifdef WIN32 |
| 14 | #include <windows.h> |
Michal Krol | 3654193 | 2006-02-18 15:11:18 +0000 | [diff] [blame] | 15 | #endif |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 16 | |
| 17 | #include <stdio.h> |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 18 | #include <stdlib.h> |
Michal Krol | 1616f5b | 2006-08-02 14:46:50 +0000 | [diff] [blame^] | 19 | #include <math.h> |
Michal Krol | 3654193 | 2006-02-18 15:11:18 +0000 | [diff] [blame] | 20 | #include <GL/gl.h> |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 21 | #include <GL/glut.h> |
| 22 | #include <GL/glext.h> |
| 23 | |
| 24 | #ifdef WIN32 |
| 25 | #define GETPROCADDRESS wglGetProcAddress |
| 26 | #else |
| 27 | #define GETPROCADDRESS glutGetProcAddress |
| 28 | #endif |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 29 | |
| 30 | static GLfloat diffuse[4] = { 0.5f, 0.5f, 1.0f, 1.0f }; |
| 31 | static GLfloat specular[4] = { 0.8f, 0.8f, 0.8f, 1.0f }; |
| 32 | static GLfloat lightPos[4] = { 0.0f, 10.0f, 20.0f, 1.0f }; |
| 33 | static GLfloat delta = 1.0f; |
| 34 | |
| 35 | static GLhandleARB fragShader; |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 36 | static GLhandleARB vertShader; |
| 37 | static GLhandleARB program; |
| 38 | |
| 39 | static GLint uLightPos; |
| 40 | static GLint uDiffuse; |
| 41 | static GLint uSpecular; |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 42 | |
| 43 | static GLboolean anim = GL_TRUE; |
| 44 | static GLboolean wire = GL_FALSE; |
| 45 | static GLboolean pixelLight = GL_TRUE; |
| 46 | |
| 47 | static GLint t0 = 0; |
| 48 | static GLint frames = 0; |
| 49 | |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 50 | static GLfloat xRot = 0.0f, yRot = 0.0f; |
| 51 | |
| 52 | static PFNGLCREATESHADEROBJECTARBPROC glCreateShaderObjectARB = NULL; |
| 53 | static PFNGLSHADERSOURCEARBPROC glShaderSourceARB = NULL; |
| 54 | static PFNGLCOMPILESHADERARBPROC glCompileShaderARB = NULL; |
| 55 | static PFNGLCREATEPROGRAMOBJECTARBPROC glCreateProgramObjectARB = NULL; |
| 56 | static PFNGLATTACHOBJECTARBPROC glAttachObjectARB = NULL; |
| 57 | static PFNGLLINKPROGRAMARBPROC glLinkProgramARB = NULL; |
| 58 | static PFNGLUSEPROGRAMOBJECTARBPROC glUseProgramObjectARB = NULL; |
| 59 | static PFNGLGETUNIFORMLOCATIONARBPROC glGetUniformLocationARB = NULL; |
Michal Krol | 1616f5b | 2006-08-02 14:46:50 +0000 | [diff] [blame^] | 60 | static PFNGLUNIFORM3FVARBPROC glUniform3fvARB = NULL; |
| 61 | static PFNGLUNIFORM3FVARBPROC glUniform4fvARB = NULL; |
| 62 | |
| 63 | static void normalize (GLfloat *dst, const GLfloat *src) |
| 64 | { |
| 65 | GLfloat len = sqrtf (src[0] * src[0] + src[1] * src[1] + src[2] * src[2]); |
| 66 | dst[0] = src[0] / len; |
| 67 | dst[1] = src[1] / len; |
| 68 | dst[2] = src[2] / len; |
| 69 | } |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 70 | |
| 71 | static void Redisplay (void) |
| 72 | { |
| 73 | glClear (GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT); |
| 74 | |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 75 | if (pixelLight) |
| 76 | { |
Michal Krol | 1616f5b | 2006-08-02 14:46:50 +0000 | [diff] [blame^] | 77 | GLfloat vec[3]; |
| 78 | |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 79 | glUseProgramObjectARB (program); |
Michal Krol | 1616f5b | 2006-08-02 14:46:50 +0000 | [diff] [blame^] | 80 | normalize (vec, lightPos); |
| 81 | glUniform3fvARB (uLightPos, 1, vec); |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 82 | glDisable(GL_LIGHTING); |
| 83 | } |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 84 | else |
| 85 | { |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 86 | glUseProgramObjectARB (0); |
| 87 | glLightfv (GL_LIGHT0, GL_POSITION, lightPos); |
| 88 | glEnable(GL_LIGHTING); |
| 89 | } |
| 90 | |
| 91 | glPushMatrix (); |
| 92 | glRotatef (xRot, 1.0f, 0.0f, 0.0f); |
| 93 | glRotatef (yRot, 0.0f, 1.0f, 0.0f); |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 94 | glutSolidSphere (2.0, 10, 5); |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 95 | glPopMatrix (); |
| 96 | |
| 97 | glutSwapBuffers(); |
| 98 | frames++; |
| 99 | |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 100 | if (anim) |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 101 | { |
| 102 | GLint t = glutGet (GLUT_ELAPSED_TIME); |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 103 | if (t - t0 >= 5000) |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 104 | { |
| 105 | GLfloat seconds = (GLfloat) (t - t0) / 1000.0f; |
| 106 | GLfloat fps = frames / seconds; |
| 107 | printf ("%d frames in %6.3f seconds = %6.3f FPS\n", frames, seconds, fps); |
| 108 | t0 = t; |
| 109 | frames = 0; |
| 110 | } |
| 111 | } |
| 112 | } |
| 113 | |
| 114 | static void Idle (void) |
| 115 | { |
| 116 | lightPos[0] += delta; |
| 117 | if (lightPos[0] > 25.0f || lightPos[0] < -25.0f) |
| 118 | delta = -delta; |
| 119 | glutPostRedisplay (); |
| 120 | } |
| 121 | |
| 122 | static void Reshape (int width, int height) |
| 123 | { |
| 124 | glViewport (0, 0, width, height); |
| 125 | glMatrixMode (GL_PROJECTION); |
| 126 | glLoadIdentity (); |
| 127 | glFrustum (-1.0, 1.0, -1.0, 1.0, 5.0, 25.0); |
| 128 | glMatrixMode (GL_MODELVIEW); |
| 129 | glLoadIdentity (); |
| 130 | glTranslatef (0.0f, 0.0f, -15.0f); |
| 131 | } |
| 132 | |
| 133 | static void Key (unsigned char key, int x, int y) |
| 134 | { |
| 135 | (void) x; |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 136 | (void) y; |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 137 | |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 138 | switch (key) |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 139 | { |
| 140 | case ' ': |
| 141 | case 'a': |
| 142 | anim = !anim; |
| 143 | if (anim) |
| 144 | glutIdleFunc (Idle); |
| 145 | else |
| 146 | glutIdleFunc (NULL); |
| 147 | break; |
| 148 | case 'x': |
| 149 | lightPos[0] -= 1.0f; |
| 150 | break; |
| 151 | case 'X': |
| 152 | lightPos[0] += 1.0f; |
| 153 | break; |
| 154 | case 'w': |
| 155 | wire = !wire; |
| 156 | if (wire) |
| 157 | glPolygonMode (GL_FRONT_AND_BACK, GL_LINE); |
| 158 | else |
| 159 | glPolygonMode (GL_FRONT_AND_BACK, GL_FILL); |
| 160 | break; |
| 161 | case 'p': |
| 162 | pixelLight = !pixelLight; |
| 163 | if (pixelLight) |
| 164 | printf ("Per-pixel lighting\n"); |
| 165 | else |
| 166 | printf ("Conventional lighting\n"); |
| 167 | break; |
| 168 | case 27: |
| 169 | exit(0); |
| 170 | break; |
| 171 | } |
| 172 | glutPostRedisplay (); |
| 173 | } |
| 174 | |
| 175 | static void SpecialKey (int key, int x, int y) |
| 176 | { |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 177 | const GLfloat step = 3.0f; |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 178 | |
| 179 | (void) x; |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 180 | (void) y; |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 181 | |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 182 | switch (key) |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 183 | { |
| 184 | case GLUT_KEY_UP: |
| 185 | xRot -= step; |
| 186 | break; |
| 187 | case GLUT_KEY_DOWN: |
| 188 | xRot += step; |
| 189 | break; |
| 190 | case GLUT_KEY_LEFT: |
| 191 | yRot -= step; |
| 192 | break; |
| 193 | case GLUT_KEY_RIGHT: |
| 194 | yRot += step; |
| 195 | break; |
| 196 | } |
| 197 | glutPostRedisplay (); |
| 198 | } |
| 199 | |
| 200 | static void Init (void) |
| 201 | { |
Michal Krol | 1616f5b | 2006-08-02 14:46:50 +0000 | [diff] [blame^] | 202 | static const char *fragShaderText = |
| 203 | "uniform vec3 lightPos;\n" |
| 204 | "uniform vec4 diffuse;\n" |
| 205 | "uniform vec4 specular;\n" |
| 206 | "varying vec3 normal;\n" |
| 207 | "void main () {\n" |
| 208 | " // Compute dot product of light direction and normal vector\n" |
| 209 | " float dotProd = max (dot (lightPos, normalize (normal)), 0.0);\n" |
| 210 | " // Compute diffuse and specular contributions\n" |
| 211 | " gl_FragColor = diffuse * dotProd + specular * pow (dotProd, 20.0);\n" |
| 212 | "}\n" |
| 213 | ; |
| 214 | static const char *vertShaderText = |
| 215 | "varying vec3 normal;\n" |
| 216 | "void main () {\n" |
| 217 | " gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n" |
| 218 | " normal = gl_NormalMatrix * gl_Normal;\n" |
| 219 | "}\n" |
| 220 | ; |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 221 | |
| 222 | if (!glutExtensionSupported ("GL_ARB_fragment_shader")) |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 223 | { |
| 224 | printf ("Sorry, this demo requires GL_ARB_fragment_shader\n"); |
| 225 | exit(1); |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 226 | } |
| 227 | if (!glutExtensionSupported ("GL_ARB_shader_objects")) |
| 228 | { |
| 229 | printf ("Sorry, this demo requires GL_ARB_shader_objects\n"); |
| 230 | exit(1); |
| 231 | } |
| 232 | if (!glutExtensionSupported ("GL_ARB_shading_language_100")) |
| 233 | { |
| 234 | printf ("Sorry, this demo requires GL_ARB_shading_language_100\n"); |
| 235 | exit(1); |
| 236 | } |
| 237 | if (!glutExtensionSupported ("GL_ARB_vertex_shader")) |
| 238 | { |
| 239 | printf ("Sorry, this demo requires GL_ARB_vertex_shader\n"); |
| 240 | exit(1); |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 241 | } |
| 242 | |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 243 | glCreateShaderObjectARB = (PFNGLCREATESHADEROBJECTARBPROC) GETPROCADDRESS ("glCreateShaderObjectARB"); |
| 244 | glShaderSourceARB = (PFNGLSHADERSOURCEARBPROC) GETPROCADDRESS ("glShaderSourceARB"); |
| 245 | glCompileShaderARB = (PFNGLCOMPILESHADERARBPROC) GETPROCADDRESS ("glCompileShaderARB"); |
| 246 | glCreateProgramObjectARB = (PFNGLCREATEPROGRAMOBJECTARBPROC) GETPROCADDRESS ("glCreateProgramObjectARB"); |
| 247 | glAttachObjectARB = (PFNGLATTACHOBJECTARBPROC) GETPROCADDRESS ("glAttachObjectARB"); |
| 248 | glLinkProgramARB = (PFNGLLINKPROGRAMARBPROC) GETPROCADDRESS ("glLinkProgramARB"); |
| 249 | glUseProgramObjectARB = (PFNGLUSEPROGRAMOBJECTARBPROC) GETPROCADDRESS ("glUseProgramObjectARB"); |
| 250 | glGetUniformLocationARB = (PFNGLGETUNIFORMLOCATIONARBPROC) GETPROCADDRESS ("glGetUniformLocationARB"); |
Michal Krol | 1616f5b | 2006-08-02 14:46:50 +0000 | [diff] [blame^] | 251 | glUniform3fvARB = (PFNGLUNIFORM3FVARBPROC) GETPROCADDRESS ("glUniform3fvARB"); |
| 252 | glUniform4fvARB = (PFNGLUNIFORM3FVARBPROC) GETPROCADDRESS ("glUniform4fvARB"); |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 253 | |
| 254 | fragShader = glCreateShaderObjectARB (GL_FRAGMENT_SHADER_ARB); |
| 255 | glShaderSourceARB (fragShader, 1, &fragShaderText, NULL); |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 256 | glCompileShaderARB (fragShader); |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 257 | |
| 258 | vertShader = glCreateShaderObjectARB (GL_VERTEX_SHADER_ARB); |
| 259 | glShaderSourceARB (vertShader, 1, &vertShaderText, NULL); |
| 260 | glCompileShaderARB (vertShader); |
| 261 | |
| 262 | program = glCreateProgramObjectARB (); |
| 263 | glAttachObjectARB (program, fragShader); |
| 264 | glAttachObjectARB (program, vertShader); |
| 265 | glLinkProgramARB (program); |
| 266 | glUseProgramObjectARB (program); |
| 267 | |
| 268 | uLightPos = glGetUniformLocationARB (program, "lightPos"); |
| 269 | uDiffuse = glGetUniformLocationARB (program, "diffuse"); |
| 270 | uSpecular = glGetUniformLocationARB (program, "specular"); |
| 271 | |
Michal Krol | 1616f5b | 2006-08-02 14:46:50 +0000 | [diff] [blame^] | 272 | glUniform4fvARB (uDiffuse, 1, diffuse); |
| 273 | glUniform4fvARB (uSpecular, 1, specular); |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 274 | |
| 275 | glClearColor (0.3f, 0.3f, 0.3f, 0.0f); |
| 276 | glEnable (GL_DEPTH_TEST); |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 277 | glEnable (GL_LIGHT0); |
Michal Krol | 3699751 | 2006-02-15 10:58:52 +0000 | [diff] [blame] | 278 | glEnable (GL_LIGHTING); |
| 279 | glMaterialfv (GL_FRONT_AND_BACK, GL_DIFFUSE, diffuse); |
| 280 | glMaterialfv (GL_FRONT_AND_BACK, GL_SPECULAR, specular); |
| 281 | glMaterialf (GL_FRONT_AND_BACK, GL_SHININESS, 20.0f); |
| 282 | |
| 283 | printf ("GL_RENDERER = %s\n", (const char *) glGetString (GL_RENDERER)); |
| 284 | printf ("Press p to toggle between per-pixel and per-vertex lighting\n"); |
| 285 | } |
| 286 | |
| 287 | int main (int argc, char *argv[]) |
| 288 | { |
| 289 | glutInit (&argc, argv); |
| 290 | glutInitWindowPosition ( 0, 0); |
| 291 | glutInitWindowSize (200, 200); |
| 292 | glutInitDisplayMode (GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH); |
| 293 | glutCreateWindow (argv[0]); |
| 294 | glutReshapeFunc (Reshape); |
| 295 | glutKeyboardFunc (Key); |
| 296 | glutSpecialFunc (SpecialKey); |
| 297 | glutDisplayFunc (Redisplay); |
| 298 | if (anim) |
| 299 | glutIdleFunc (Idle); |
| 300 | Init (); |
| 301 | glutMainLoop (); |
| 302 | return 0; |
| 303 | } |
Michal Krol | 6acf1e9 | 2006-04-25 10:11:59 +0000 | [diff] [blame] | 304 | |