progs/egl/opengles1/drawtex.c

   1 /*
   2  * Copyright (C) 2008  Tunsgten Graphics,Inc.   All Rights Reserved.
   3  */
   4
   5 /*
   6  * Test GL_OES_draw_texture
   7  * Brian Paul
   8  * August 2008
   9  */
  10
  11 #define GL_GLEXT_PROTOTYPES
  12
  13 #include <math.h>
  14 #include <stdlib.h>
  15 #include <stdio.h>
  16 #include <string.h>
  17 #include <GLES/gl.h>
  18 #include <GLES/glext.h>
  19
  20 #include "eglut.h"
  21
  22
  23 static GLfloat view_posx = 10.0, view_posy = 20.0;
  24 static GLfloat width = 200, height = 200;
  25 static GLboolean animate = GL_FALSE;
  26 static int win;
  27
  28
  29 static void
  30 draw(void)
  31 {
  32    glClear(GL_COLOR_BUFFER_BIT);
  33
  34    glDrawTexfOES(view_posx, view_posy, 0.0, width, height);
  35 }
  36
  37
  38 /* new window size or exposure */
  39 static void
  40 reshape(int width, int height)
  41 {
  42    GLfloat ar = (GLfloat) width / (GLfloat) height;
  43
  44    glViewport(0, 0, (GLint) width, (GLint) height);
  45
  46    glMatrixMode(GL_PROJECTION);
  47    glLoadIdentity();
  48
  49 #ifdef GL_VERSION_ES_CM_1_0
  50    glFrustumf(-ar, ar, -1, 1, 5.0, 60.0);
  51 #else
  52    glFrustum(-ar, ar, -1, 1, 5.0, 60.0);
  53 #endif
  54
  55    glMatrixMode(GL_MODELVIEW);
  56    glLoadIdentity();
  57    glTranslatef(0.0, 0.0, -15.0);
  58 }
  59
  60
  61 static float
  62 dist(GLuint i, GLuint j, float x, float y)
  63 {
  64    return sqrt((i-x) * (i-x) + (j-y) * (j-y));
  65 }
  66
  67 static void
  68 make_smile_texture(void)
  69 {
  70 #define SZ 128
  71    GLenum Filter = GL_LINEAR;
  72    GLubyte image[SZ][SZ][4];
  73    GLuint i, j;
  74    GLint cropRect[4];
  75
  76    for (i = 0; i < SZ; i++) {
  77       for (j = 0; j < SZ; j++) {
  78          GLfloat d_mouth = dist(i, j, SZ/2, SZ/2);
  79          GLfloat d_rt_eye = dist(i, j, SZ*3/4, SZ*3/4);
  80          GLfloat d_lt_eye = dist(i, j, SZ*3/4, SZ*1/4);
  81          if (d_rt_eye < SZ / 8 || d_lt_eye < SZ / 8) {
  82             image[i][j][0] = 20;
  83             image[i][j][1] = 50;
  84             image[i][j][2] = 255;
  85             image[i][j][3] = 255;
  86          }
  87          else if (i < SZ/2 && d_mouth < SZ/3) {
  88             image[i][j][0] = 255;
  89             image[i][j][1] = 20;
  90             image[i][j][2] = 20;
  91             image[i][j][3] = 255;
  92          }
  93          else {
  94             image[i][j][0] = 200;
  95             image[i][j][1] = 200;
  96             image[i][j][2] = 200;
  97             image[i][j][3] = 255;
  98          }
  99       }
 100    }
 101
 102    glActiveTexture(GL_TEXTURE0); /* unit 0 */
 103    glBindTexture(GL_TEXTURE_2D, 42);
 104    glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, SZ, SZ, 0,
 105                 GL_RGBA, GL_UNSIGNED_BYTE, image);
 106    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, Filter);
 107    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, Filter);
 108    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_REPEAT);
 109    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_REPEAT);
 110
 111    cropRect[0] = 0;
 112    cropRect[1] = 0;
 113    cropRect[2] = SZ;
 114    cropRect[3] = SZ;
 115    glTexParameteriv(GL_TEXTURE_2D, GL_TEXTURE_CROP_RECT_OES, cropRect);
 116 #undef SZ
 117 }
 118
 119
 120
 121 static void
 122 init(void)
 123 {
 124    const char *ext = (char *) glGetString(GL_EXTENSIONS);
 125
 126    if (!strstr(ext, "GL_OES_draw_texture")) {
 127       fprintf(stderr, "Sorry, this program requires GL_OES_draw_texture");
 128       exit(1);
 129    }
 130
 131    glClearColor(0.4, 0.4, 0.4, 0.0);
 132
 133    make_smile_texture();
 134    glEnable(GL_TEXTURE_2D);
 135 }
 136
 137
 138 static void
 139 idle(void)
 140 {
 141    if (animate) {
 142       view_posx += 1.0;
 143       view_posy += 2.0;
 144       eglutPostRedisplay();
 145    }
 146 }
 147
 148 static void
 149 key(unsigned char key)
 150 {
 151    switch (key) {
 152    case ' ':
 153       animate = !animate;
 154       break;
 155    case 'w':
 156       width -= 1.0f;
 157       break;
 158    case 'W':
 159       width += 1.0f;
 160       break;
 161    case 'h':
 162       height -= 1.0f;
 163       break;
 164    case 'H':
 165       height += 1.0f;
 166       break;
 167    case 27:
 168       eglutDestroyWindow(win);
 169       exit(0);
 170       break;
 171    default:
 172       break;
 173    }
 174 }
 175
 176 static void
 177 special_key(int key)
 178 {
 179    switch (key) {
 180    case EGLUT_KEY_LEFT:
 181       view_posx -= 1.0;
 182       break;
 183    case EGLUT_KEY_RIGHT:
 184       view_posx += 1.0;
 185       break;
 186    case EGLUT_KEY_UP:
 187       view_posy += 1.0;
 188       break;
 189    case EGLUT_KEY_DOWN:
 190       view_posy -= 1.0;
 191       break;
 192    default:
 193       break;
 194    }
 195 }
 196
 197 int
 198 main(int argc, char *argv[])
 199 {
 200    eglutInitWindowSize(400, 300);
 201    eglutInitAPIMask(EGLUT_OPENGL_ES1_BIT);
 202    eglutInit(argc, argv);
 203
 204    win = eglutCreateWindow("drawtex");
 205
 206    eglutIdleFunc(idle);
 207    eglutReshapeFunc(reshape);
 208    eglutDisplayFunc(draw);
 209    eglutKeyboardFunc(key);
 210    eglutSpecialFunc(special_key);
 211
 212    init();
 213
 214    eglutMainLoop();
 215
 216    return 0;
 217 }