progs/tests/scissor-viewport.c

   1 /*
   2  * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
   3  * Copyright (c) 2009 VMware, Inc.
   4  *
   5  * Permission to use, copy, modify, distribute, and sell this software and
   6  * its documentation for any purpose is hereby granted without fee, provided
   7  * that (i) the above copyright notices and this permission notice appear in
   8  * all copies of the software and related documentation, and (ii) the name of
   9  * Silicon Graphics may not be used in any advertising or
  10  * publicity relating to the software without the specific, prior written
  11  * permission of Silicon Graphics.
  12  *
  13  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
  14  * ANY KIND,
  15  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  16  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  17  *
  18  * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
  19  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  20  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  21  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  22  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  23  * OF THIS SOFTWARE.
  24  */
  25
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <stdlib.h>
  29 #include <GL/glut.h>
  30
  31 struct program
  32 {
  33    unsigned width;
  34    unsigned height;
  35    int i;
  36 };
  37
  38 struct program prog;
  39
  40 static void init(void)
  41 {
  42    fprintf(stderr, "GL_RENDERER   = %s\n", (char *) glGetString(GL_RENDERER));
  43    fprintf(stderr, "GL_VERSION    = %s\n", (char *) glGetString(GL_VERSION));
  44    fprintf(stderr, "GL_VENDOR     = %s\n", (char *) glGetString(GL_VENDOR));
  45    fflush(stderr);
  46
  47    prog.i = 0;
  48 }
  49
  50 static void reshape(int width, int height)
  51 {
  52    glViewport(0, 0, 100, 100);
  53
  54    prog.width = width;
  55    prog.height = height;
  56
  57    glMatrixMode(GL_PROJECTION);
  58    glLoadIdentity();
  59    glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  60    glMatrixMode(GL_MODELVIEW);
  61 }
  62
  63 static void key(unsigned char key, int x, int y)
  64 {
  65
  66    switch (key) {
  67    case 27:
  68       exit(1);
  69    default:
  70       glutPostRedisplay();
  71       return;
  72    }
  73 }
  74
  75 static void drawQuad(void)
  76 {
  77    glBegin(GL_QUADS);
  78    glVertex2d(-1.0, -1.0);
  79    glVertex2d( 1.0, -1.0);
  80    glVertex2d( 1.0,  1.0);
  81    glVertex2d(-1.0,  1.0);
  82    glEnd();
  83 }
  84
  85 static void draw(void)
  86 {
  87    int i;
  88
  89    glClearColor(0.0, 0.0, 1.0, 0.0);
  90    glClear(GL_COLOR_BUFFER_BIT);
  91
  92    i = prog.i++;
  93    if (prog.i >= 3)
  94       prog.i = 0;
  95
  96    glEnable(GL_SCISSOR_TEST);
  97
  98    {
  99       glColor4d(1.0, 0.0, 0.0, 1.0);
 100
 101       glScissor(i, i, 10 - 2*i, 10 - 2*i);
 102       drawQuad();
 103    }
 104
 105    glDisable(GL_SCISSOR_TEST);
 106
 107    /* glutSwapBuffers(); */
 108    glFlush();
 109 }
 110
 111 int main(int argc, char **argv)
 112 {
 113    GLenum type;
 114
 115    glutInit(&argc, argv);
 116
 117    prog.width = 200;
 118    prog.height = 200;
 119
 120    glutInitWindowPosition(100, 0);
 121    glutInitWindowSize(prog.width, prog.height);
 122
 123    /* type = GLUT_RGB | GLUT_DOUBLE; */
 124    type = GLUT_RGB | GLUT_SINGLE;
 125    glutInitDisplayMode(type);
 126
 127    if (glutCreateWindow(*argv) == GL_FALSE) {
 128       exit(1);
 129    }
 130
 131    init();
 132
 133    glutReshapeFunc(reshape);
 134    glutKeyboardFunc(key);
 135    glutDisplayFunc(draw);
 136    glutMainLoop();
 137    return 0;
 138 }