progs/tests/scissor.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    unsigned quads;
  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
  48 static void reshape(int width, int height)
  49 {
  50
  51    glViewport(0, 0, (GLint)width, (GLint)height);
  52
  53    prog.width = width;
  54    prog.height = height;
  55
  56    glMatrixMode(GL_PROJECTION);
  57    glLoadIdentity();
  58    glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  59    glMatrixMode(GL_MODELVIEW);
  60 }
  61
  62 static void key(unsigned char key, int x, int y)
  63 {
  64
  65    switch (key) {
  66    case 27:
  67       exit(1);
  68    default:
  69       prog.quads = !prog.quads;
  70       glutPostRedisplay();
  71       return;
  72    }
  73 }
  74
  75 static void drawQuad(void)
  76 {
  77
  78    if (prog.quads) {
  79       glBegin(GL_QUADS);
  80       glVertex2d(-1.0, -1.0);
  81       glVertex2d( 1.0, -1.0);
  82       glVertex2d( 1.0,  1.0);
  83       glVertex2d(-1.0,  1.0);
  84       glEnd();
  85    } else {
  86       glClear(GL_COLOR_BUFFER_BIT);
  87    }
  88 }
  89
  90 static void draw(void)
  91 {
  92    glClearColor(0.0, 0.0, 1.0, 0.0);
  93    glClear(GL_COLOR_BUFFER_BIT);
  94
  95    printf("drawing with %s\n", prog.quads ? "quads" : "clears");
  96
  97    glEnable(GL_SCISSOR_TEST);
  98
  99    {
 100       glClearColor(1.0, 0.0, 0.0, 1.0);
 101       glColor4d(1.0, 0.0, 0.0, 1.0);
 102
 103       glScissor(1, 1, 10, 10);
 104       drawQuad();
 105       glScissor(1, prog.height -  11, 10, 10);
 106       drawQuad();
 107       glScissor(prog.width - 11, prog.height -  11, 10, 10);
 108       drawQuad();
 109    }
 110
 111    {
 112       glClearColor(0.0, 1.0, 0.0, 1.0);
 113       glColor4d(0.0, 1.0, 0.0, 1.0);
 114
 115       glScissor(12, 1, 10, 10);
 116       drawQuad();
 117       glScissor(12, prog.height -  11, 10, 10);
 118       drawQuad();
 119       glScissor(prog.width - 22, prog.height -  11, 10, 10);
 120       drawQuad();
 121    }
 122
 123    {
 124       glClearColor(1.0, 1.0, 0.0, 1.0);
 125       glColor4d(1.0, 1.0, 0.0, 1.0);
 126
 127       glScissor(1, 12, 10, 10);
 128       drawQuad();
 129       glScissor(1, prog.height -  22, 10, 10);
 130       drawQuad();
 131       glScissor(prog.width - 11, prog.height -  22, 10, 10);
 132       drawQuad();
 133    }
 134
 135    glDisable(GL_SCISSOR_TEST);
 136
 137    /* glutSwapBuffers(); */
 138    glFlush();
 139 }
 140
 141 int main(int argc, char **argv)
 142 {
 143    GLenum type;
 144
 145    glutInit(&argc, argv);
 146
 147    prog.width = 200;
 148    prog.height = 200;
 149
 150    glutInitWindowPosition(100, 0);
 151    glutInitWindowSize(prog.width, prog.height);
 152
 153    /* type = GLUT_RGB | GLUT_DOUBLE; */
 154    type = GLUT_RGB | GLUT_SINGLE;
 155    glutInitDisplayMode(type);
 156
 157    if (glutCreateWindow(*argv) == GL_FALSE) {
 158       exit(1);
 159    }
 160
 161    init();
 162
 163    glutReshapeFunc(reshape);
 164    glutKeyboardFunc(key);
 165    glutDisplayFunc(draw);
 166    glutMainLoop();
 167    return 0;
 168 }