progs/fp/tri-lg2.c

   1 /*
   2  * Copyright (c) 1991, 1992, 1993 Silicon Graphics, Inc.
   3  *
   4  * Permission to use, copy, modify, distribute, and sell this software and
   5  * its documentation for any purpose is hereby granted without fee, provided
   6  * that (i) the above copyright notices and this permission notice appear in
   7  * all copies of the software and related documentation, and (ii) the name of
   8  * Silicon Graphics may not be used in any advertising or
   9  * publicity relating to the software without the specific, prior written
  10  * permission of Silicon Graphics.
  11  *
  12  * THE SOFTWARE IS PROVIDED "AS-IS" AND WITHOUT WARRANTY OF
  13  * ANY KIND,
  14  * EXPRESS, IMPLIED OR OTHERWISE, INCLUDING WITHOUT LIMITATION, ANY
  15  * WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
  16  *
  17  * IN NO EVENT SHALL SILICON GRAPHICS BE LIABLE FOR
  18  * ANY SPECIAL, INCIDENTAL, INDIRECT OR CONSEQUENTIAL DAMAGES OF ANY KIND,
  19  * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
  20  * WHETHER OR NOT ADVISED OF THE POSSIBILITY OF DAMAGE, AND ON ANY THEORY OF
  21  * LIABILITY, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
  22  * OF THIS SOFTWARE.
  23  */
  24
  25 #include <stdio.h>
  26 #include <string.h>
  27 #include <stdlib.h>
  28 #define GL_GLEXT_PROTOTYPES
  29 #include <GL/glut.h>
  30
  31
  32 #define CI_OFFSET_1 16
  33 #define CI_OFFSET_2 32
  34
  35
  36 GLenum doubleBuffer;
  37
  38 static void Init( void )
  39 {
  40    static const char *modulate2D =
  41       "!!ARBfp1.0\n"
  42       "TEMP R0;\n"
  43       "MUL R0, fragment.color, {4.0}.x; \n"
  44       "LG2 result.color, R0.x; \n"
  45       "END"
  46       ;
  47    GLuint modulateProg;
  48
  49    if (!glutExtensionSupported("GL_ARB_fragment_program")) {
  50       printf("Error: GL_ARB_fragment_program not supported!\n");
  51       exit(1);
  52    }
  53    printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
  54
  55    /* Setup the fragment program */
  56    glGenProgramsARB(1, &modulateProg);
  57    glBindProgramARB(GL_FRAGMENT_PROGRAM_ARB, modulateProg);
  58    glProgramStringARB(GL_FRAGMENT_PROGRAM_ARB, GL_PROGRAM_FORMAT_ASCII_ARB,
  59                         strlen(modulate2D), (const GLubyte *)modulate2D);
  60
  61    printf("glGetError = 0x%x\n", (int) glGetError());
  62    printf("glError(GL_PROGRAM_ERROR_STRING_ARB) = %s\n",
  63           (char *) glGetString(GL_PROGRAM_ERROR_STRING_ARB));
  64
  65    glEnable(GL_FRAGMENT_PROGRAM_ARB);
  66
  67    glClearColor(.3, .3, .3, 0);
  68 }
  69
  70 static void Reshape(int width, int height)
  71 {
  72
  73     glViewport(0, 0, (GLint)width, (GLint)height);
  74
  75     glMatrixMode(GL_PROJECTION);
  76     glLoadIdentity();
  77     glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0);
  78     glMatrixMode(GL_MODELVIEW);
  79 }
  80
  81 static void Key(unsigned char key, int x, int y)
  82 {
  83
  84     switch (key) {
  85       case 27:
  86         exit(1);
  87       default:
  88         return;
  89     }
  90
  91     glutPostRedisplay();
  92 }
  93
  94 static void Draw(void)
  95 {
  96    glClear(GL_COLOR_BUFFER_BIT);
  97
  98    glBegin(GL_TRIANGLES);
  99    glColor3f(0,0,1);
 100    glVertex3f( 0.9, -0.9, -30.0);
 101    glColor3f(1,0,0);
 102    glVertex3f( 0.9,  0.9, -30.0);
 103    glColor3f(0,1,0);
 104    glVertex3f(-0.9,  0.0, -30.0);
 105    glEnd();
 106
 107    glFlush();
 108
 109    if (doubleBuffer) {
 110       glutSwapBuffers();
 111    }
 112 }
 113
 114 static GLenum Args(int argc, char **argv)
 115 {
 116     GLint i;
 117
 118     doubleBuffer = GL_FALSE;
 119
 120     for (i = 1; i < argc; i++) {
 121         if (strcmp(argv[i], "-sb") == 0) {
 122             doubleBuffer = GL_FALSE;
 123         } else if (strcmp(argv[i], "-db") == 0) {
 124             doubleBuffer = GL_TRUE;
 125         } else {
 126             fprintf(stderr, "%s (Bad option).\n", argv[i]);
 127             return GL_FALSE;
 128         }
 129     }
 130     return GL_TRUE;
 131 }
 132
 133 int main(int argc, char **argv)
 134 {
 135     GLenum type;
 136
 137     glutInit(&argc, argv);
 138
 139     if (Args(argc, argv) == GL_FALSE) {
 140         exit(1);
 141     }
 142
 143     glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250);
 144
 145     type = GLUT_RGB;
 146     type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
 147     glutInitDisplayMode(type);
 148
 149     if (glutCreateWindow("First Tri") == GL_FALSE) {
 150         exit(1);
 151     }
 152
 153     Init();
 154
 155     glutReshapeFunc(Reshape);
 156     glutKeyboardFunc(Key);
 157     glutDisplayFunc(Draw);
 158     glutMainLoop();
 159         return 0;
 160 }