progs/glsl/texdemo1.c

   1 /**
   2  * Test texturing with GL shading language.
   3  *
   4  * Copyright (C) 2007  Brian Paul   All Rights Reserved.
   5  *
   6  * Permission is hereby granted, free of charge, to any person obtaining a
   7  * copy of this software and associated documentation files (the "Software"),
   8  * to deal in the Software without restriction, including without limitation
   9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  10  * and/or sell copies of the Software, and to permit persons to whom the
  11  * Software is furnished to do so, subject to the following conditions:
  12  *
  13  * The above copyright notice and this permission notice shall be included
  14  * in all copies or substantial portions of the Software.
  15  *
  16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  17  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  19  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  20  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  21  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22  */
  23
  24
  25
  26 #include <assert.h>
  27 #include <math.h>
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <string.h>
  31 #include <GL/glew.h>
  32 #include "GL/glut.h"
  33 #include "readtex.h"
  34 #include "shaderutil.h"
  35
  36 static const char *Demo = "texdemo1";
  37
  38 static const char *ReflectVertFile = "reflect.vert";
  39 static const char *CubeFragFile = "cubemap.frag";
  40
  41 static const char *SimpleVertFile = "simple.vert";
  42 static const char *SimpleTexFragFile = "shadowtex.frag";
  43
  44 static const char *GroundImage = "../images/tile.rgb";
  45
  46 static GLuint Program1, Program2;
  47
  48 static GLfloat TexXrot = 0, TexYrot = 0;
  49 static GLfloat Xrot = 20.0, Yrot = 20.0, Zrot = 0.0;
  50 static GLfloat EyeDist = 10;
  51 static GLboolean Anim = GL_TRUE;
  52 static int win = 0;
  53
  54
  55 static struct uniform_info ReflectUniforms[] = {
  56    { "cubeTex",  1, GL_SAMPLER_CUBE, { 0, 0, 0, 0 }, -1 },
  57    { "lightPos", 1, GL_FLOAT_VEC3, { 10, 10, 20, 0 }, -1 },
  58    END_OF_UNIFORMS
  59 };
  60
  61 static struct uniform_info SimpleUniforms[] = {
  62    { "tex2d",    1, GL_SAMPLER_2D, { 1, 0, 0, 0 }, -1 },
  63    { "lightPos", 1, GL_FLOAT_VEC3, { 10, 10, 20, 0 }, -1 },
  64    END_OF_UNIFORMS
  65 };
  66
  67
  68 static void
  69 DrawGround(GLfloat size)
  70 {
  71    glPushMatrix();
  72    glRotatef(90, 1, 0, 0);
  73    glNormal3f(0, 0, 1);
  74    glBegin(GL_POLYGON);
  75    glTexCoord2f(-2, -2);  glVertex2f(-size, -size);
  76    glTexCoord2f( 2, -2);  glVertex2f( size, -size);
  77    glTexCoord2f( 2,  2);  glVertex2f( size,  size);
  78    glTexCoord2f(-2,  2);  glVertex2f(-size,  size);
  79    glEnd();
  80    glPopMatrix();
  81 }
  82
  83
  84 static void
  85 draw(void)
  86 {
  87    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  88
  89    glEnable(GL_TEXTURE_2D);
  90
  91    glPushMatrix(); /* modelview matrix */
  92       glTranslatef(0.0, 0.0, -EyeDist);
  93       glRotatef(Xrot, 1, 0, 0);
  94       glRotatef(Yrot, 0, 1, 0);
  95       glRotatef(Zrot, 0, 0, 1);
  96
  97       /* sphere w/ reflection map */
  98       glPushMatrix();
  99          glTranslatef(0, 1, 0);
 100          glUseProgram(Program1);
 101
 102          /* setup texture matrix */
 103          glActiveTexture(GL_TEXTURE0);
 104          glMatrixMode(GL_TEXTURE);
 105          glLoadIdentity();
 106          glRotatef(-TexYrot, 0, 1, 0);
 107          glRotatef(-TexXrot, 1, 0, 0);
 108
 109          glEnable(GL_TEXTURE_GEN_S);
 110          glEnable(GL_TEXTURE_GEN_T);
 111          glEnable(GL_TEXTURE_GEN_R);
 112          glutSolidSphere(2.0, 20, 20);
 113
 114          glLoadIdentity(); /* texture matrix */
 115          glMatrixMode(GL_MODELVIEW);
 116       glPopMatrix();
 117
 118       /* ground */
 119       glUseProgram(Program2);
 120       glTranslatef(0, -1.0, 0);
 121       DrawGround(5);
 122
 123    glPopMatrix();
 124
 125    glutSwapBuffers();
 126 }
 127
 128
 129 static void
 130 idle(void)
 131 {
 132    GLfloat t = 0.05 * glutGet(GLUT_ELAPSED_TIME);
 133    TexYrot = t;
 134    glutPostRedisplay();
 135 }
 136
 137
 138 static void
 139 key(unsigned char k, int x, int y)
 140 {
 141    (void) x;
 142    (void) y;
 143    switch (k) {
 144    case ' ':
 145    case 'a':
 146       Anim = !Anim;
 147       if (Anim)
 148          glutIdleFunc(idle);
 149       else
 150          glutIdleFunc(NULL);
 151       break;
 152    case 'z':
 153       EyeDist -= 0.5;
 154       if (EyeDist < 6.0)
 155          EyeDist = 6.0;
 156       break;
 157    case 'Z':
 158       EyeDist += 0.5;
 159       if (EyeDist > 90.0)
 160          EyeDist = 90;
 161       break;
 162    case 27:
 163       glutDestroyWindow(win);
 164       exit(0);
 165    }
 166    glutPostRedisplay();
 167 }
 168
 169
 170 static void
 171 specialkey(int key, int x, int y)
 172 {
 173    GLfloat step = 2.0;
 174    (void) x;
 175    (void) y;
 176    switch (key) {
 177    case GLUT_KEY_UP:
 178       Xrot += step;
 179       break;
 180    case GLUT_KEY_DOWN:
 181       Xrot -= step;
 182       break;
 183    case GLUT_KEY_LEFT:
 184       Yrot -= step;
 185       break;
 186    case GLUT_KEY_RIGHT:
 187       Yrot += step;
 188       break;
 189    }
 190    glutPostRedisplay();
 191 }
 192
 193
 194 /* new window size or exposure */
 195 static void
 196 Reshape(int width, int height)
 197 {
 198    GLfloat ar = (float) width / (float) height;
 199    glViewport(0, 0, (GLint)width, (GLint)height);
 200    glMatrixMode(GL_PROJECTION);
 201    glLoadIdentity();
 202    glFrustum(-2.0*ar, 2.0*ar, -2.0, 2.0, 4.0, 100.0);
 203    glMatrixMode(GL_MODELVIEW);
 204    glLoadIdentity();
 205 }
 206
 207
 208 static void
 209 InitCheckers(void)
 210 {
 211 #define CUBE_TEX_SIZE 64
 212    GLubyte image[CUBE_TEX_SIZE][CUBE_TEX_SIZE][3];
 213    static const GLubyte colors[6][3] = {
 214       { 255,   0,   0 },        /* face 0 - red */
 215       {   0, 255, 255 },        /* face 1 - cyan */
 216       {   0, 255,   0 },        /* face 2 - green */
 217       { 255,   0, 255 },        /* face 3 - purple */
 218       {   0,   0, 255 },        /* face 4 - blue */
 219       { 255, 255,   0 }         /* face 5 - yellow */
 220    };
 221    static const GLenum targets[6] = {
 222       GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB,
 223       GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB,
 224       GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB,
 225       GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB,
 226       GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB,
 227       GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB
 228    };
 229
 230    GLint i, j, f;
 231
 232    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 233
 234    /* make colored checkerboard cube faces */
 235    for (f = 0; f < 6; f++) {
 236       for (i = 0; i < CUBE_TEX_SIZE; i++) {
 237          for (j = 0; j < CUBE_TEX_SIZE; j++) {
 238             if ((i/4 + j/4) & 1) {
 239                image[i][j][0] = colors[f][0];
 240                image[i][j][1] = colors[f][1];
 241                image[i][j][2] = colors[f][2];
 242             }
 243             else {
 244                image[i][j][0] = 255;
 245                image[i][j][1] = 255;
 246                image[i][j][2] = 255;
 247             }
 248          }
 249       }
 250
 251       glTexImage2D(targets[f], 0, GL_RGB, CUBE_TEX_SIZE, CUBE_TEX_SIZE, 0,
 252                    GL_RGB, GL_UNSIGNED_BYTE, image);
 253    }
 254 }
 255
 256
 257 static void
 258 LoadFace(GLenum target, const char *filename,
 259          GLboolean flipTB, GLboolean flipLR)
 260 {
 261    GLint w, h;
 262    GLenum format;
 263    GLubyte *img = LoadRGBImage(filename, &w, &h, &format);
 264    if (!img) {
 265       printf("Error: couldn't load texture image %s\n", filename);
 266       exit(1);
 267    }
 268    assert(format == GL_RGB);
 269
 270    /* <sigh> the way the texture cube mapping works, we have to flip
 271     * images to make things look right.
 272     */
 273    if (flipTB) {
 274       const int stride = 3 * w;
 275       GLubyte temp[3*1024];
 276       int i;
 277       for (i = 0; i < h / 2; i++) {
 278          memcpy(temp, img + i * stride, stride);
 279          memcpy(img + i * stride, img + (h - i - 1) * stride, stride);
 280          memcpy(img + (h - i - 1) * stride, temp, stride);
 281       }
 282    }
 283    if (flipLR) {
 284       const int stride = 3 * w;
 285       GLubyte temp[3];
 286       GLubyte *row;
 287       int i, j;
 288       for (i = 0; i < h; i++) {
 289          row = img + i * stride;
 290          for (j = 0; j < w / 2; j++) {
 291             int k = w - j - 1;
 292             temp[0] = row[j*3+0];
 293             temp[1] = row[j*3+1];
 294             temp[2] = row[j*3+2];
 295             row[j*3+0] = row[k*3+0];
 296             row[j*3+1] = row[k*3+1];
 297             row[j*3+2] = row[k*3+2];
 298             row[k*3+0] = temp[0];
 299             row[k*3+1] = temp[1];
 300             row[k*3+2] = temp[2];
 301          }
 302       }
 303    }
 304
 305    gluBuild2DMipmaps(target, GL_RGB, w, h, format, GL_UNSIGNED_BYTE, img);
 306    free(img);
 307 }
 308
 309
 310 static void
 311 LoadEnvmaps(void)
 312 {
 313    LoadFace(GL_TEXTURE_CUBE_MAP_POSITIVE_X_ARB, "right.rgb", GL_TRUE, GL_FALSE);
 314    LoadFace(GL_TEXTURE_CUBE_MAP_NEGATIVE_X_ARB, "left.rgb", GL_TRUE, GL_FALSE);
 315    LoadFace(GL_TEXTURE_CUBE_MAP_POSITIVE_Y_ARB, "top.rgb", GL_FALSE, GL_TRUE);
 316    LoadFace(GL_TEXTURE_CUBE_MAP_NEGATIVE_Y_ARB, "bottom.rgb", GL_FALSE, GL_TRUE);
 317    LoadFace(GL_TEXTURE_CUBE_MAP_POSITIVE_Z_ARB, "front.rgb", GL_TRUE, GL_FALSE);
 318    LoadFace(GL_TEXTURE_CUBE_MAP_NEGATIVE_Z_ARB, "back.rgb", GL_TRUE, GL_FALSE);
 319 }
 320
 321
 322 static void
 323 InitTextures(GLboolean useImageFiles)
 324 {
 325    GLenum filter;
 326
 327    /*
 328     * Env map
 329     */
 330    glActiveTexture(GL_TEXTURE0);
 331    glBindTexture(GL_TEXTURE_CUBE_MAP, 1);
 332    if (useImageFiles) {
 333       LoadEnvmaps();
 334       filter = GL_LINEAR;
 335    }
 336    else {
 337       InitCheckers();
 338       filter = GL_NEAREST;
 339    }
 340    glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MIN_FILTER, filter);
 341    glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_MAG_FILTER, filter);
 342    glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
 343    glTexParameteri(GL_TEXTURE_CUBE_MAP_ARB, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
 344
 345    /*
 346     * Ground texture
 347     */
 348    {
 349       GLint imgWidth, imgHeight;
 350       GLenum imgFormat;
 351       GLubyte *image = NULL;
 352
 353       image = LoadRGBImage(GroundImage, &imgWidth, &imgHeight, &imgFormat);
 354       if (!image) {
 355          printf("Couldn't read %s\n", GroundImage);
 356          exit(0);
 357       }
 358
 359       glActiveTexture(GL_TEXTURE1);
 360       glBindTexture(GL_TEXTURE_2D, 2);
 361       gluBuild2DMipmaps(GL_TEXTURE_2D, 3, imgWidth, imgHeight,
 362                         imgFormat, GL_UNSIGNED_BYTE, image);
 363       free(image);
 364
 365       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 366       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 367       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 368       glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 369    }
 370 }
 371
 372
 373 static GLuint
 374 CreateProgram(const char *vertProgFile, const char *fragProgFile,
 375               struct uniform_info *uniforms)
 376 {
 377    GLuint fragShader, vertShader, program;
 378
 379    vertShader = CompileShaderFile(GL_VERTEX_SHADER, vertProgFile);
 380    fragShader = CompileShaderFile(GL_FRAGMENT_SHADER, fragProgFile);
 381    program = LinkShaders(vertShader, fragShader);
 382
 383    glUseProgram(program);
 384
 385    SetUniformValues(program, uniforms);
 386    PrintUniforms(uniforms);
 387
 388    return program;
 389 }
 390
 391
 392 static void
 393 InitPrograms(void)
 394 {
 395    Program1 = CreateProgram(ReflectVertFile, CubeFragFile, ReflectUniforms);
 396    Program2 = CreateProgram(SimpleVertFile, SimpleTexFragFile, SimpleUniforms);
 397 }
 398
 399
 400 static void
 401 Init(GLboolean useImageFiles)
 402 {
 403    if (!ShadersSupported()) {
 404       exit(1);
 405    }
 406    printf("GL_RENDERER = %s\n",(const char *) glGetString(GL_RENDERER));
 407
 408    InitTextures(useImageFiles);
 409    InitPrograms();
 410
 411    glEnable(GL_DEPTH_TEST);
 412
 413    glClearColor(.6, .6, .9, 0);
 414    glColor3f(1.0, 1.0, 1.0);
 415 }
 416
 417
 418 int
 419 main(int argc, char *argv[])
 420 {
 421    glutInit(&argc, argv);
 422    glutInitWindowSize(500, 400);
 423    glutInitDisplayMode(GLUT_RGB | GLUT_DEPTH | GLUT_DOUBLE);
 424    win = glutCreateWindow(Demo);
 425    glewInit();
 426    glutReshapeFunc(Reshape);
 427    glutKeyboardFunc(key);
 428    glutSpecialFunc(specialkey);
 429    glutDisplayFunc(draw);
 430    if (Anim)
 431       glutIdleFunc(idle);
 432    if (argc > 1 && strcmp(argv[1] , "-i") == 0)
 433       Init(1);
 434    else
 435       Init(0);
 436    glutMainLoop();
 437    return 0;
 438 }