progs/tests/zbitmap.c

   1 /*
   2  * Test Z values of glBitmap.
   3  * Brian Paul
   4  * 19 Feb 2010
   5  */
   6
   7
   8 #include <assert.h>
   9 #include <stdio.h>
  10 #include <stdlib.h>
  11 #include <string.h>
  12 #include <math.h>
  13 #include <GL/glew.h>
  14 #include <GL/glut.h>
  15
  16
  17 static GLint Win = 0;
  18
  19
  20 static void
  21 PrintString(const char *s)
  22 {
  23    while (*s) {
  24       glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
  25       s++;
  26    }
  27 }
  28
  29
  30 static void
  31 Display(void)
  32 {
  33    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
  34
  35    glMatrixMode(GL_PROJECTION);
  36    glLoadIdentity();
  37    glOrtho(-3.0, 3.0, -3.0, 3.0, -2.0, 2.0);
  38
  39    glMatrixMode(GL_MODELVIEW);
  40    glLoadIdentity();
  41
  42    glColor3f(1, 1, 1);
  43    glRasterPos2f(-2.0, 2.6);
  44    PrintString("Z = -1.0");
  45    glRasterPos2f(-0.5, 2.6);
  46    PrintString("Z = 0.0");
  47    glRasterPos2f(1.0, 2.6);
  48    PrintString("Z = 1.0");
  49
  50    glColor3f(0, 0.4, 0.6);
  51    glBegin(GL_QUADS);
  52    glVertex3f(-2.0, -2.5, -1);
  53    glVertex3f(-1.0, -2.5, -1);
  54    glVertex3f(-1.0, 2.5, -1);
  55    glVertex3f(-2.0, 2.5, -1);
  56
  57    glVertex3f(-0.5, -2.5, 0);
  58    glVertex3f(0.5, -2.5, 0);
  59    glVertex3f(0.5, 2.5, 0);
  60    glVertex3f(-0.5, 2.5, 0);
  61
  62    glVertex3f(1.0, -2.5, 1);
  63    glVertex3f(2.0, -2.5, 1);
  64    glVertex3f(2.0, 2.5, 1);
  65    glVertex3f(1.0, 2.5, 1);
  66    glEnd();
  67
  68    glColor3f(1, 1, 1);
  69
  70    glRasterPos3f(-2.0, -1, -1.0);
  71    PrintString("This is a bitmap string drawn at z = -1.0");
  72
  73    glRasterPos3f(-2.0, 0, 0.0);
  74    PrintString("This is a bitmap string drawn at z = 0.0");
  75
  76    glRasterPos3f(-2.0, 1, 1.0);
  77    PrintString("This is a bitmap string drawn at z = 1.0");
  78
  79    glRasterPos3f(-1.5, -2.8, 0.0);
  80    PrintString("GL_DEPTH_FUNC = GL_LEQUAL");
  81
  82    glutSwapBuffers();
  83 }
  84
  85
  86 static void
  87 Reshape(int width, int height)
  88 {
  89    glViewport(0, 0, width, height);
  90 }
  91
  92
  93 static void
  94 Key(unsigned char key, int x, int y)
  95 {
  96    if (key == 27) {
  97       glutDestroyWindow(Win);
  98       exit(0);
  99    }
 100    glutPostRedisplay();
 101 }
 102
 103
 104 static void
 105 Init(void)
 106 {
 107    glClearColor(0.25, 0.25, 0.25, 0.0);
 108    glDepthFunc(GL_LEQUAL);
 109    glEnable(GL_DEPTH_TEST);
 110 }
 111
 112
 113 int
 114 main(int argc, char *argv[])
 115 {
 116    glutInitWindowSize(400, 400);
 117    glutInit(&argc, argv);
 118    glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
 119    Win = glutCreateWindow(argv[0]);
 120    glewInit();
 121    glutReshapeFunc(Reshape);
 122    glutKeyboardFunc(Key);
 123    glutDisplayFunc(Display);
 124    Init();
 125    glutMainLoop();
 126    return 0;
 127 }