Example/Test.c

   1 /*
   2  * Test program for glpng
   3  * by Ben Wyatt ben@wyatt100.freeserve.co.uk
   4  * Featuring a shameless plug for my stunt course program
   5  * Available from the same site as glpng
   6  * http://www.wyatt100.freeserve.co.uk/download.htm
   7  */
   8
   9 #include <GL/glpng.h>
  10 #include <GL/glut.h>
  11 #include <stdlib.h>
  12
  13 int angle = 0;
  14
  15 /***** GLUT callback functions *****/
  16
  17 void KeyPress(unsigned char key, int x, int y) {
  18         switch (key) {
  19                 case 27: /*ESC*/ glutDestroyWindow(glutGetWindow()); exit(0); break;
  20         }
  21 }
  22
  23 void Update(void) {
  24         angle = (angle+1)%360;
  25         glutPostRedisplay();
  26 }
  27
  28 void Display(void) {
  29         const float w = 2, h = 2;
  30
  31         glClear(GL_COLOR_BUFFER_BIT);
  32
  33         glLoadIdentity();
  34         glTranslatef(0, 0, -10);
  35         glRotatef(angle, 0, 1, 0);
  36
  37         glBegin(GL_QUADS);
  38                 // Front
  39                 glTexCoord2f(1, 1); glVertex3f( w, -h, 0);
  40                 glTexCoord2f(1, 0); glVertex3f( w,  h, 0);
  41                 glTexCoord2f(0, 0); glVertex3f(-w,  h, 0);
  42                 glTexCoord2f(0, 1); glVertex3f(-w, -h, 0);
  43
  44                 // Back
  45                 glTexCoord2f(1, 1); glVertex3f(-w, -h, 0);
  46                 glTexCoord2f(1, 0); glVertex3f(-w,  h, 0);
  47                 glTexCoord2f(0, 0); glVertex3f( w,  h, 0);
  48                 glTexCoord2f(0, 1); glVertex3f( w, -h, 0);
  49         glEnd();
  50
  51         glutSwapBuffers();
  52 }
  53
  54 void Reshape(int w, int h) {
  55         glViewport(0, 0, w, h);
  56
  57         glMatrixMode(GL_PROJECTION);
  58         glLoadIdentity();
  59         gluPerspective(30, (float) w/h, 1, 100);
  60
  61         glMatrixMode(GL_MODELVIEW);
  62         Display();
  63 }
  64
  65 /***** Main function *****/
  66
  67 void main() {
  68         pngInfo info;
  69         GLuint  texture;
  70
  71         glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB);
  72         glutInitWindowSize(300, 300);
  73         glutCreateWindow("glpng test");
  74
  75         #if 0 // Using pngLoad and setting texture parameters manually.
  76                 glGenTextures(1, &texture);
  77                 glBindTexture(GL_TEXTURE_2D, texture);
  78
  79                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST);
  80                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST);
  81                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_S, GL_CLAMP);
  82                 glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_WRAP_T, GL_CLAMP);
  83
  84                 if (!pngLoad("Stunt.png", PNG_NOMIPMAP, PNG_SOLID, &info)) {
  85                         puts("Can't load file");
  86                         exit(1);
  87                 }
  88         #else // Using pngLoadAndBind to set texture parameters automatically.
  89                 texture = pngBind("Stunt.png", PNG_NOMIPMAP, PNG_ALPHA, &info, GL_CLAMP, GL_NEAREST, GL_NEAREST);
  90
  91                 if (texture == 0) {
  92                         puts("Can't load file");
  93                         exit(1);
  94                 }
  95         #endif
  96
  97         printf("Size=%i,%i Depth=%i Alpha=%i\n", info.Width, info.Height, info.Depth, info.Alpha);
  98
  99         glEnable(GL_TEXTURE_2D);
 100         glBindTexture(GL_TEXTURE_2D, texture);
 101         glEnable(GL_CULL_FACE);
 102         glColor3f(1, 1, 1);
 103
 104         glutKeyboardFunc(KeyPress);
 105         glutIdleFunc(Update);
 106         glutDisplayFunc(Display);
 107         glutReshapeFunc(Reshape);
 108
 109         glutMainLoop();
 110 }