#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <GL/glut.h>
GLenum doubleBuffer;
GLint thing1, thing2;
static void Init(void)
{
glClearColor(0.0, 0.0, 0.0, 0.0);
glClearAccum(0.0, 0.0, 0.0, 0.0);
thing1 = glGenLists(1);
glNewList(thing1, GL_COMPILE);
glColor3f(1.0, 0.0, 0.0);
glRectf(-1.0, -1.0, 1.0, 0.0);
glEndList();
thing2 = glGenLists(1);
glNewList(thing2, GL_COMPILE);
glColor3f(0.0, 1.0, 0.0);
glRectf(0.0, -1.0, 1.0, 1.0);
glEndList();
}
static void Reshape(int width, int height)
{
glViewport(0, 0, (GLint)width, (GLint)height);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
static void Key(unsigned char key, int x, int y)
{
(void) x;
(void) y;
switch (key) {
case 27:
exit(1);
case '1':
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
break;
case '2':
glPolygonMode(GL_FRONT_AND_BACK, GL_LINE);
break;
default:
return;
}
glutPostRedisplay();
}
static void Draw(void)
{
glPushMatrix();
glScalef(0.8, 0.8, 1.0);
glClear(GL_COLOR_BUFFER_BIT);
glCallList(thing1);
glAccum(GL_LOAD, 0.5);
glClear(GL_COLOR_BUFFER_BIT);
glCallList(thing2);
glAccum(GL_ACCUM, 0.5);
glAccum(GL_RETURN, 1.0);
glPopMatrix();
glFlush();
if (doubleBuffer) {
glutSwapBuffers();
}
}
static GLenum Args(int argc, char **argv)
{
GLint i;
doubleBuffer = GL_FALSE;
for (i = 1; i < argc; i++) {
if (strcmp(argv[i], "-sb") == 0) {
doubleBuffer = GL_FALSE;
} else if (strcmp(argv[i], "-db") == 0) {
doubleBuffer = GL_TRUE;
} else {
printf("%s (Bad option).\n", argv[i]);
return GL_FALSE;
}
}
return GL_TRUE;
}
int main(int argc, char **argv)
{
GLenum type;
glutInit(&argc, argv);
if (Args(argc, argv) == GL_FALSE) {
exit(1);
}
glutInitWindowPosition(0, 0);
glutInitWindowSize( 300, 300);
type = GLUT_RGB | GLUT_ACCUM;
type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE;
glutInitDisplayMode(type);
if (glutCreateWindow("Accum Test") == GL_FALSE) {
exit(1);
}
Init();
glutReshapeFunc(Reshape);
glutKeyboardFunc(Key);
glutDisplayFunc(Draw);
glutMainLoop();
return 0;
}