progs/fp/fp-tri.c

   1
   2 #include <stdio.h>
   3 #include <string.h>
   4 #include <stdlib.h>
   5
   6 #ifndef WIN32
   7 #include <unistd.h>
   8 #include <signal.h>
   9 #endif
  10
  11 #include <GL/glew.h>
  12 #include <GL/glut.h>
  13
  14 #include "readtex.c"
  15
  16
  17 #define TEXTURE_FILE "../images/bw.rgb"
  18
  19 unsigned show_fps = 0;
  20 unsigned int frame_cnt = 0;
  21 void alarmhandler(int);
  22 static const char *filename = NULL;
  23
  24 static void usage(char *name)
  25 {
  26    fprintf(stderr, "usage: %s [ options ] shader_filename\n", name);
  27 #ifndef WIN32
  28    fprintf(stderr, "\n" );
  29    fprintf(stderr, "options:\n");
  30    fprintf(stderr, "    -fps  show frames per second\n");
  31 #endif
  32 }
  33
  34 #ifndef WIN32
  35 void alarmhandler (int sig)
  36 {
  37    if (sig == SIGALRM) {
  38       printf("%d frames in 5.0 seconds = %.3f FPS\n", frame_cnt,
  39              frame_cnt / 5.0);
  40
  41       frame_cnt = 0;
  42    }
  43    signal(SIGALRM, alarmhandler);
  44    alarm(5);
  45 }
  46 #endif
  47
  48 static void args(int argc, char *argv[])
  49 {
  50    GLint i;
  51
  52    for (i = 1; i < argc; i++) {
  53       if (strcmp(argv[i], "-fps") == 0) {
  54          show_fps = 1;
  55       }
  56       else if (i == argc - 1) {
  57          filename = argv[i];
  58       }
  59       else {
  60          usage(argv[0]);
  61          exit(1);
  62       }
  63    }
  64
  65    if (!filename) {
  66       usage(argv[0]);
  67       exit(1);
  68    }
  69 }
  70
  71 static void Init( void )
  72 {
  73    GLuint Texture;
  74    GLint errno;
  75    GLuint prognum;
  76    char buf[50000];
  77    GLuint sz;
  78    FILE *f;
  79
  80    if ((f = fopen(filename, "r")) == NULL) {
  81       fprintf(stderr, "Couldn't open %s\n", filename);
  82       exit(1);
  83    }
  84
  85    sz = fread(buf, 1, sizeof(buf), f);
  86    if (!feof(f)) {
  87       fprintf(stderr, "file too long\n");
  88       exit(1);
  89    }
  90    fprintf(stderr, "%.*s\n", sz, buf);
  91
  92    if (!GLEW_ARB_fragment_program) {
  93       printf("Error: GL_ARB_fragment_program not supported!\n");
  94       exit(1);
  95    }
  96    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
  97
  98    /* Setup the fragment program */
  99    glGenProgramsARB(1, &prognum);
 100    glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, prognum);
 101    glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB,
 102                       sz, (const GLubyte *)buf);
 103
 104    errno = glGetError();
 105    printf("glGetError = 0x%x\n", errno);
 106    if (errno != GL_NO_ERROR) {
 107       GLint errorpos;
 108
 109       glGetIntegerv(GL_PROGRAM_ERROR_POSITION_ARB, &errorpos);
 110       printf("errorpos: %d\n", errorpos);
 111       printf("glError(GL_PROGRAM_ERROR_STRING_ARB) = %s\n",
 112              (char *) glGetString(GL_PROGRAM_ERROR_STRING_ARB));
 113    }
 114    glEnable(GL_FRAGMENT_PROGRAM_ARB);
 115
 116
 117    /* Load texture */
 118    glGenTextures(1, &Texture);
 119    glBindTexture(GL_TEXTURE_2D, Texture);
 120    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
 121    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
 122    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 123    if (!LoadRGBMipmaps(TEXTURE_FILE, GL_RGB)) {
 124       printf("Error: couldn't load texture image file %s\n", TEXTURE_FILE);
 125       exit(1);
 126    }
 127
 128
 129    glGenTextures(1, &Texture);
 130    glActiveTextureARB(GL_TEXTURE0_ARB + 1);
 131    glBindTexture(GL_TEXTURE_2D, Texture);
 132    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
 133    glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
 134    glPixelStorei(GL_UNPACK_ALIGNMENT, 1);
 135
 136    {
 137       GLubyte data[32][32];
 138       int width = 32;
 139       int height = 32;
 140       int i;
 141       int j;
 142
 143       for (i = 0; i < 32; i++)
 144          for (j = 0; j < 32; j++)
 145          {
 146             /**
 147              ** +-----------+
 148              ** |     W     |
 149              ** |  +-----+  |
 150              ** |  |     |  |
 151              ** |  |  B  |  |
 152              ** |  |     |  |
 153              ** |  +-----+  |
 154              ** |           |
 155              ** +-----------+
 156              **/
 157             int i2 = i - height / 2;
 158             int j2 = j - width / 2;
 159             int h8 = height / 8;
 160             int w8 = width / 8;
 161             if ( -h8 <= i2 && i2 <= h8 && -w8 <= j2 && j2 <= w8 ) {
 162                data[i][j] = 0x00;
 163             } else if ( -2 * h8 <= i2 && i2 <= 2 * h8 && -2 * w8 <= j2 && j2 <= 2 * w8 ) {
 164                data[i][j] = 0x55;
 165             } else if ( -3 * h8 <= i2 && i2 <= 3 * h8 && -3 * w8 <= j2 && j2 <= 3 * w8 ) {
 166                data[i][j] = 0xaa;
 167             } else {
 168                data[i][j] = 0xff;
 169             }
 170          }
 171
 172       glTexImage2D( GL_TEXTURE_2D, 0,
 173                     GL_ALPHA8,
 174                     32, 32, 0,
 175                     GL_ALPHA, GL_UNSIGNED_BYTE, data );
 176    }
 177
 178
 179    {
 180       const float Ambient[4] = { 0.0, 1.0, 0.0, 0.0 };
 181       const float Diffuse[4] = { 1.0, 0.0, 0.0, 0.0 };
 182       const float Specular[4] = { 0.0, 0.0, 1.0, 0.0 };
 183       const float Emission[4] = { 0.0, 0.0, 0.0, 1.0 };
 184       glMaterialfv(GL_FRONT_AND_BACK, GL_AMBIENT, Ambient);
 185       glMaterialfv(GL_FRONT_AND_BACK, GL_DIFFUSE, Diffuse);
 186       glMaterialfv(GL_FRONT_AND_BACK, GL_SPECULAR, Specular);
 187       glMaterialfv(GL_FRONT_AND_BACK, GL_EMISSION, Emission);
 188    }
 189
 190    glClearColor(.1, .3, .5, 0);
 191    fclose(f);
 192 }
 193
 194 static void Reshape(int width, int height)
 195 {
 196
 197     glViewport(0, 0, (GLint)width, (GLint)height);
 198
 199     glMatrixMode(GL_PROJECTION);
 200     glLoadIdentity();
 201     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
 202     glMatrixMode(GL_MODELVIEW);
 203 }
 204
 205 static void Key(unsigned char key, int x, int y)
 206 {
 207
 208     switch (key) {
 209       case 27:
 210         exit(1);
 211       default:
 212         break;
 213     }
 214
 215     glutPostRedisplay();
 216 }
 217
 218 static void Display(void)
 219 {
 220    glClear(GL_COLOR_BUFFER_BIT);
 221
 222    glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 0, 1.0, 1.0, 0.0, 0.0);
 223    glProgramLocalParameter4fARB(GL_FRAGMENT_PROGRAM_ARB, 1, 0.0, 0.0, 1.0, 1.0);
 224    glBegin(GL_TRIANGLES);
 225
 226    glColor3f(0,0,1);
 227    glTexCoord3f(1,1,0);
 228    glVertex3f( 0.9, -0.9, -30.0);
 229
 230    glColor3f(1,0,0);
 231    glTexCoord3f(1,-1,0);
 232    glVertex3f( 0.9,  0.9, -30.0);
 233
 234    glColor3f(0,1,0);
 235    glTexCoord3f(-1,0,0);
 236    glVertex3f(-0.9,  0.0, -30.0);
 237    glEnd();
 238
 239    glFlush();
 240    if (show_fps) {
 241       ++frame_cnt;
 242       glutPostRedisplay();
 243    }
 244 }
 245
 246
 247 int main(int argc, char **argv)
 248 {
 249    glutInit(&argc, argv);
 250    glutInitWindowPosition(0, 0);
 251    glutInitWindowSize(250, 250);
 252    glutInitDisplayMode(GLUT_RGB | GLUT_SINGLE | GLUT_DEPTH);
 253    args(argc, argv);
 254    glutCreateWindow(filename);
 255    glewInit();
 256    glutReshapeFunc(Reshape);
 257    glutKeyboardFunc(Key);
 258    glutDisplayFunc(Display);
 259    Init();
 260 #ifndef WIN32
 261    if (show_fps) {
 262       signal(SIGALRM, alarmhandler);
 263       alarm(5);
 264    }
 265 #endif
 266    glutMainLoop();
 267    return 0;
 268 }