progs/demos/fslight.c

   1 /**
   2  * Test OpenGL 2.0 vertex/fragment shaders.
   3  * Brian Paul
   4  * 1 November 2006
   5  *
   6  * Based on ARB version by:
   7  * Michal Krol
   8  * 20 February 2006
   9  *
  10  * Based on the original demo by:
  11  * Brian Paul
  12  * 17 April 2003
  13  */
  14
  15 #include <assert.h>
  16 #include <string.h>
  17 #include <stdio.h>
  18 #include <stdlib.h>
  19 #include <math.h>
  20 #include <GL/gl.h>
  21 #include <GL/glut.h>
  22 #include <GL/glext.h>
  23 #include "extfuncs.h"
  24
  25
  26 #define TEXTURE 0
  27
  28 static GLint CoordAttrib = 0;
  29
  30 static char *FragProgFile = NULL;
  31 static char *VertProgFile = NULL;
  32
  33 static GLfloat diffuse[4] = { 0.5f, 0.5f, 1.0f, 1.0f };
  34 static GLfloat specular[4] = { 0.8f, 0.8f, 0.8f, 1.0f };
  35 static GLfloat lightPos[4] = { 0.0f, 10.0f, 20.0f, 0.0f };
  36 static GLfloat delta = 1.0f;
  37
  38 static GLuint fragShader;
  39 static GLuint vertShader;
  40 static GLuint program;
  41
  42 static GLint uDiffuse;
  43 static GLint uSpecular;
  44 static GLint uTexture;
  45
  46 static GLuint SphereList, RectList, CurList;
  47 static GLint win = 0;
  48 static GLboolean anim = GL_TRUE;
  49 static GLboolean wire = GL_FALSE;
  50 static GLboolean pixelLight = GL_TRUE;
  51
  52 static GLint t0 = 0;
  53 static GLint frames = 0;
  54
  55 static GLfloat xRot = 90.0f, yRot = 0.0f;
  56
  57
  58 static void
  59 normalize(GLfloat *dst, const GLfloat *src)
  60 {
  61    GLfloat len = sqrt(src[0] * src[0] + src[1] * src[1] + src[2] * src[2]);
  62    dst[0] = src[0] / len;
  63    dst[1] = src[1] / len;
  64    dst[2] = src[2] / len;
  65    dst[3] = src[3];
  66 }
  67
  68
  69 static void
  70 Redisplay(void)
  71 {
  72    GLfloat vec[4];
  73
  74    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  75
  76    /* update light position */
  77    normalize(vec, lightPos);
  78    glLightfv(GL_LIGHT0, GL_POSITION, vec);
  79
  80    if (pixelLight) {
  81       glUseProgram_func(program);
  82       glDisable(GL_LIGHTING);
  83    }
  84    else {
  85       glUseProgram_func(0);
  86       glEnable(GL_LIGHTING);
  87    }
  88
  89    glPushMatrix();
  90    glRotatef(xRot, 1.0f, 0.0f, 0.0f);
  91    glRotatef(yRot, 0.0f, 1.0f, 0.0f);
  92    /*
  93    glutSolidSphere(2.0, 10, 5);
  94    */
  95    glCallList(CurList);
  96    glPopMatrix();
  97
  98    glutSwapBuffers();
  99    frames++;
 100
 101    if (anim) {
 102       GLint t = glutGet(GLUT_ELAPSED_TIME);
 103       if (t - t0 >= 5000) {
 104          GLfloat seconds =(GLfloat)(t - t0) / 1000.0f;
 105          GLfloat fps = frames / seconds;
 106          printf("%d frames in %6.3f seconds = %6.3f FPS\n",
 107                 frames, seconds, fps);
 108          t0 = t;
 109          frames = 0;
 110       }
 111    }
 112 }
 113
 114
 115 static void
 116 Idle(void)
 117 {
 118    lightPos[0] += delta;
 119    if (lightPos[0] > 25.0f || lightPos[0] < -25.0f)
 120       delta = -delta;
 121    glutPostRedisplay();
 122 }
 123
 124
 125 static void
 126 Reshape(int width, int height)
 127 {
 128    glViewport(0, 0, width, height);
 129    glMatrixMode(GL_PROJECTION);
 130    glLoadIdentity();
 131    glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
 132    glMatrixMode(GL_MODELVIEW);
 133    glLoadIdentity();
 134    glTranslatef(0.0f, 0.0f, -15.0f);
 135 }
 136
 137
 138 static void
 139 CleanUp(void)
 140 {
 141    glDeleteShader_func(fragShader);
 142    glDeleteShader_func(vertShader);
 143    glDeleteProgram_func(program);
 144    glutDestroyWindow(win);
 145 }
 146
 147
 148 static void
 149 Key(unsigned char key, int x, int y)
 150 {
 151   (void) x;
 152   (void) y;
 153
 154    switch(key) {
 155    case ' ':
 156    case 'a':
 157       anim = !anim;
 158       if (anim)
 159          glutIdleFunc(Idle);
 160       else
 161          glutIdleFunc(NULL);
 162       break;
 163    case 'x':
 164       lightPos[0] -= 1.0f;
 165       break;
 166    case 'X':
 167       lightPos[0] += 1.0f;
 168       break;
 169    case 'w':
 170       wire = !wire;
 171       if (wire)
 172          glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
 173       else
 174          glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
 175       break;
 176    case 'o':
 177       if (CurList == SphereList)
 178          CurList = RectList;
 179       else
 180          CurList = SphereList;
 181       break;
 182    case 'p':
 183       pixelLight = !pixelLight;
 184       if (pixelLight)
 185          printf("Per-pixel lighting\n");
 186       else
 187          printf("Conventional lighting\n");
 188       break;
 189    case 27:
 190       CleanUp();
 191       exit(0);
 192       break;
 193    }
 194    glutPostRedisplay();
 195 }
 196
 197
 198 static void
 199 SpecialKey(int key, int x, int y)
 200 {
 201    const GLfloat step = 3.0f;
 202
 203   (void) x;
 204   (void) y;
 205
 206    switch(key) {
 207    case GLUT_KEY_UP:
 208       xRot -= step;
 209       break;
 210    case GLUT_KEY_DOWN:
 211       xRot += step;
 212       break;
 213    case GLUT_KEY_LEFT:
 214       yRot -= step;
 215       break;
 216    case GLUT_KEY_RIGHT:
 217       yRot += step;
 218       break;
 219    }
 220    glutPostRedisplay();
 221 }
 222
 223
 224 static void
 225 TestFunctions(void)
 226 {
 227    printf("Error 0x%x at line %d\n", glGetError(), __LINE__);
 228
 229    assert(glIsProgram_func(program));
 230    assert(glIsShader_func(fragShader));
 231    assert(glIsShader_func(vertShader));
 232
 233    /* attached shaders */
 234    {
 235       GLuint shaders[20];
 236       GLsizei count;
 237       int i;
 238       glGetAttachedShaders_func(program, 20, &count, shaders);
 239       for (i = 0; i < count; i++) {
 240          printf("Attached: %u\n", shaders[i]);
 241          assert(shaders[i] == fragShader ||
 242                 shaders[i] == vertShader);
 243       }
 244    }
 245
 246    {
 247       GLchar log[1000];
 248       GLsizei len;
 249       glGetShaderInfoLog_func(vertShader, 1000, &len, log);
 250       printf("Vert Shader Info Log: %s\n", log);
 251       glGetShaderInfoLog_func(fragShader, 1000, &len, log);
 252       printf("Frag Shader Info Log: %s\n", log);
 253       glGetProgramInfoLog_func(program, 1000, &len, log);
 254       printf("Program Info Log: %s\n", log);
 255    }
 256
 257    /* active uniforms */
 258    {
 259       GLint n, max, i;
 260       glGetProgramiv_func(program, GL_ACTIVE_UNIFORMS, &n);
 261       glGetProgramiv_func(program, GL_ACTIVE_UNIFORM_MAX_LENGTH, &max);
 262       printf("Num uniforms: %d  Max name length: %d\n", n, max);
 263       for (i = 0; i < n; i++) {
 264          GLint size, len;
 265          GLenum type;
 266          char name[100];
 267          glGetActiveUniform_func(program, i, 100, &len, &size, &type, name);
 268          printf("  %d: %s nameLen=%d size=%d type=0x%x\n",
 269                 i, name, len, size, type);
 270       }
 271    }
 272 }
 273
 274
 275 #if TEXTURE
 276 static void
 277 MakeTexture(void)
 278 {
 279 #define SZ0 64
 280 #define SZ1 32
 281    GLubyte image0[SZ0][SZ0][SZ0][4];
 282    GLubyte image1[SZ1][SZ1][SZ1][4];
 283    GLuint i, j, k;
 284
 285    /* level 0: two-tone gray checkboard */
 286    for (i = 0; i < SZ0; i++) {
 287       for (j = 0; j < SZ0; j++) {
 288          for (k = 0; k < SZ0; k++) {
 289             if ((i/8 + j/8 + k/8) & 1) {
 290                image0[i][j][k][0] =
 291                image0[i][j][k][1] =
 292                image0[i][j][k][2] = 200;
 293             }
 294             else {
 295                image0[i][j][k][0] =
 296                image0[i][j][k][1] =
 297                image0[i][j][k][2] = 100;
 298             }
 299             image0[i][j][k][3] = 255;
 300          }
 301       }
 302    }
 303
 304    /* level 1: two-tone green checkboard */
 305    for (i = 0; i < SZ1; i++) {
 306       for (j = 0; j < SZ1; j++) {
 307          for (k = 0; k < SZ1; k++) {
 308             if ((i/8 + j/8 + k/8) & 1) {
 309                image1[i][j][k][0] = 0;
 310                image1[i][j][k][1] = 250;
 311                image1[i][j][k][2] = 0;
 312             }
 313             else {
 314                image1[i][j][k][0] = 0;
 315                image1[i][j][k][1] = 200;
 316                image1[i][j][k][2] = 0;
 317             }
 318             image1[i][j][k][3] = 255;
 319          }
 320       }
 321    }
 322
 323    glActiveTexture(GL_TEXTURE2); /* unit 2 */
 324    glBindTexture(GL_TEXTURE_2D, 42);
 325    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, SZ0, SZ0, 0,
 326                 GL_RGBA, GL_UNSIGNED_BYTE, image0);
 327    glTexImage2D(GL_TEXTURE_2D, 1, GL_RGBA, SZ1, SZ1, 0,
 328                 GL_RGBA, GL_UNSIGNED_BYTE, image1);
 329    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAX_LEVEL, 1);
 330    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 331    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 332
 333    glActiveTexture(GL_TEXTURE4); /* unit 4 */
 334    glBindTexture(GL_TEXTURE_3D, 43);
 335    glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA, SZ0, SZ0, SZ0, 0,
 336                 GL_RGBA, GL_UNSIGNED_BYTE, image0);
 337    glTexImage3D(GL_TEXTURE_3D, 1, GL_RGBA, SZ1, SZ1, SZ1, 0,
 338                 GL_RGBA, GL_UNSIGNED_BYTE, image1);
 339    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAX_LEVEL, 1);
 340    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 341    glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 342 }
 343 #endif
 344
 345
 346 static void
 347 MakeSphere(void)
 348 {
 349    GLUquadricObj *obj = gluNewQuadric();
 350    SphereList = glGenLists(1);
 351    gluQuadricTexture(obj, GL_TRUE);
 352    glNewList(SphereList, GL_COMPILE);
 353    gluSphere(obj, 2.0f, 10, 5);
 354    glEndList();
 355 }
 356
 357 static void
 358 VertAttrib(GLint index, float x, float y)
 359 {
 360 #if 1
 361    glVertexAttrib2f_func(index, x, y);
 362 #else
 363    glTexCoord2f(x, y);
 364 #endif
 365 }
 366
 367 static void
 368 MakeRect(void)
 369 {
 370    RectList = glGenLists(1);
 371    glNewList(RectList, GL_COMPILE);
 372    glNormal3f(0, 0, 1);
 373    glBegin(GL_POLYGON);
 374    VertAttrib(CoordAttrib, 0, 0);   glVertex2f(-2, -2);
 375    VertAttrib(CoordAttrib, 1, 0);   glVertex2f( 2, -2);
 376    VertAttrib(CoordAttrib, 1, 1);   glVertex2f( 2,  2);
 377    VertAttrib(CoordAttrib, 0, 1);   glVertex2f(-2,  2);
 378    glEnd();    /* XXX omit this and crash! */
 379    glEndList();
 380 }
 381
 382
 383
 384 static void
 385 LoadAndCompileShader(GLuint shader, const char *text)
 386 {
 387    GLint stat;
 388
 389    glShaderSource_func(shader, 1, (const GLchar **) &text, NULL);
 390
 391    glCompileShader_func(shader);
 392
 393    glGetShaderiv_func(shader, GL_COMPILE_STATUS, &stat);
 394    if (!stat) {
 395       GLchar log[1000];
 396       GLsizei len;
 397       glGetShaderInfoLog_func(shader, 1000, &len, log);
 398       fprintf(stderr, "fslight: problem compiling shader:\n%s\n", log);
 399       exit(1);
 400    }
 401 }
 402
 403
 404 /**
 405  * Read a shader from a file.
 406  */
 407 static void
 408 ReadShader(GLuint shader, const char *filename)
 409 {
 410    const int max = 100*1000;
 411    int n;
 412    char *buffer = (char*) malloc(max);
 413    FILE *f = fopen(filename, "r");
 414    if (!f) {
 415       fprintf(stderr, "fslight: Unable to open shader file %s\n", filename);
 416       exit(1);
 417    }
 418
 419    n = fread(buffer, 1, max, f);
 420    printf("fslight: read %d bytes from shader file %s\n", n, filename);
 421    if (n > 0) {
 422       buffer[n] = 0;
 423       LoadAndCompileShader(shader, buffer);
 424    }
 425
 426    fclose(f);
 427    free(buffer);
 428 }
 429
 430
 431 static void
 432 CheckLink(GLuint prog)
 433 {
 434    GLint stat;
 435    glGetProgramiv_func(prog, GL_LINK_STATUS, &stat);
 436    if (!stat) {
 437       GLchar log[1000];
 438       GLsizei len;
 439       glGetProgramInfoLog_func(prog, 1000, &len, log);
 440       fprintf(stderr, "Linker error:\n%s\n", log);
 441    }
 442 }
 443
 444
 445 static void
 446 Init(void)
 447 {
 448    static const char *fragShaderText =
 449       "uniform vec4 diffuse;\n"
 450       "uniform vec4 specular;\n"
 451       "varying vec3 normal;\n"
 452       "void main() {\n"
 453       "   // Compute dot product of light direction and normal vector\n"
 454       "   float dotProd = max(dot(gl_LightSource[0].position.xyz, \n"
 455       "                           normalize(normal)), 0.0);\n"
 456       "   // Compute diffuse and specular contributions\n"
 457       "   gl_FragColor = diffuse * dotProd + specular * pow(dotProd, 20.0);\n"
 458       "}\n";
 459    static const char *vertShaderText =
 460       "varying vec3 normal;\n"
 461       "void main() {\n"
 462       "   gl_Position = gl_ModelViewProjectionMatrix * gl_Vertex;\n"
 463       "   normal = gl_NormalMatrix * gl_Normal;\n"
 464       "}\n";
 465    const char *version;
 466
 467    version = (const char *) glGetString(GL_VERSION);
 468    if (version[0] != '2' || version[1] != '.') {
 469       printf("This program requires OpenGL 2.x, found %s\n", version);
 470       exit(1);
 471    }
 472
 473    GetExtensionFuncs();
 474
 475    fragShader = glCreateShader_func(GL_FRAGMENT_SHADER);
 476    if (FragProgFile)
 477       ReadShader(fragShader, FragProgFile);
 478    else
 479       LoadAndCompileShader(fragShader, fragShaderText);
 480
 481
 482    vertShader = glCreateShader_func(GL_VERTEX_SHADER);
 483    if (VertProgFile)
 484       ReadShader(vertShader, VertProgFile);
 485    else
 486       LoadAndCompileShader(vertShader, vertShaderText);
 487
 488    program = glCreateProgram_func();
 489    glAttachShader_func(program, fragShader);
 490    glAttachShader_func(program, vertShader);
 491    glLinkProgram_func(program);
 492    CheckLink(program);
 493    glUseProgram_func(program);
 494
 495    uDiffuse = glGetUniformLocation_func(program, "diffuse");
 496    uSpecular = glGetUniformLocation_func(program, "specular");
 497    uTexture = glGetUniformLocation_func(program, "texture");
 498    printf("DiffusePos %d  SpecularPos %d  TexturePos %d\n",
 499           uDiffuse, uSpecular, uTexture);
 500
 501    glUniform4fv_func(uDiffuse, 1, diffuse);
 502    glUniform4fv_func(uSpecular, 1, specular);
 503    /*   assert(glGetError() == 0);*/
 504 #if TEXTURE
 505    glUniform1i_func(uTexture, 2);  /* use texture unit 2 */
 506 #endif
 507    /*assert(glGetError() == 0);*/
 508
 509    if (CoordAttrib) {
 510       int i;
 511       glBindAttribLocation_func(program, CoordAttrib, "coord");
 512       i = glGetAttribLocation_func(program, "coord");
 513       assert(i >= 0);
 514       if (i != CoordAttrib) {
 515          printf("Hmmm, NVIDIA bug?\n");
 516          CoordAttrib = i;
 517       }
 518       else {
 519          printf("Mesa bind attrib: coord = %d\n", i);
 520       }
 521    }
 522
 523    /*assert(glGetError() == 0);*/
 524
 525    glClearColor(0.3f, 0.3f, 0.3f, 0.0f);
 526    glEnable(GL_DEPTH_TEST);
 527    glEnable(GL_LIGHT0);
 528    glEnable(GL_LIGHTING);
 529    glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, diffuse);
 530    glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, specular);
 531    glMaterialf(GL_FRONT_AND_BACK, GL_SHININESS, 20.0f);
 532
 533    MakeSphere();
 534    MakeRect();
 535
 536    CurList = SphereList;
 537
 538 #if TEXTURE
 539    MakeTexture();
 540 #endif
 541
 542    printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
 543    printf("Press p to toggle between per-pixel and per-vertex lighting\n");
 544
 545    /* test glGetShaderSource() */
 546    if (0) {
 547       GLsizei len = strlen(fragShaderText) + 1;
 548       GLsizei lenOut;
 549       GLchar *src =(GLchar *) malloc(len * sizeof(GLchar));
 550       glGetShaderSource_func(fragShader, 0, NULL, src);
 551       glGetShaderSource_func(fragShader, len, &lenOut, src);
 552       assert(len == lenOut + 1);
 553       assert(strcmp(src, fragShaderText) == 0);
 554       free(src);
 555    }
 556
 557    assert(glIsProgram_func(program));
 558    assert(glIsShader_func(fragShader));
 559    assert(glIsShader_func(vertShader));
 560
 561    glColor3f(1, 0, 0);
 562
 563    /* for testing state vars */
 564    {
 565       static GLfloat fc[4] = { 1, 1, 0, 0 };
 566       static GLfloat amb[4] = { 1, 0, 1, 0 };
 567       glFogfv(GL_FOG_COLOR, fc);
 568       glLightfv(GL_LIGHT1, GL_AMBIENT, amb);
 569    }
 570
 571 #if 0
 572    TestFunctions();
 573 #else
 574    (void) TestFunctions;
 575 #endif
 576 }
 577
 578
 579 static void
 580 ParseOptions(int argc, char *argv[])
 581 {
 582    int i;
 583    for (i = 1; i < argc; i++) {
 584       if (strcmp(argv[i], "-fs") == 0) {
 585          FragProgFile = argv[i+1];
 586       }
 587       else if (strcmp(argv[i], "-vs") == 0) {
 588          VertProgFile = argv[i+1];
 589       }
 590    }
 591 }
 592
 593
 594 int
 595 main(int argc, char *argv[])
 596 {
 597    glutInit(&argc, argv);
 598    glutInitWindowPosition( 0, 0);
 599    glutInitWindowSize(200, 200);
 600    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 601    win = glutCreateWindow(argv[0]);
 602    glutReshapeFunc(Reshape);
 603    glutKeyboardFunc(Key);
 604    glutSpecialFunc(SpecialKey);
 605    glutDisplayFunc(Redisplay);
 606    if (anim)
 607       glutIdleFunc(Idle);
 608    ParseOptions(argc, argv);
 609    Init();
 610    glutMainLoop();
 611    return 0;
 612 }
 613
 614