ANTIPNT.C

/* 
* (c) Copyright 1993, Silicon Graphics, Inc.
* 1993-1995 Microsoft Corporation
*
* ALL RIGHTS RESERVED
*
* Please refer to OpenGL/readme.txt for additional information
*
*/

/*
* antipoint.c
* The program draws antialiased points, in RGBA mode.
*/
#include "glos.h"

#include <GL/gl.h>
#include <GL/glu.h>
#include <GL/glaux.h>

void myinit(void);
void CALLBACK myReshape(GLsizei w, GLsizei h);
void CALLBACK display(void);

/* Initialize point anti-aliasing for RGBA mode, including alpha
* blending, hint, and point size. These points are 3.0 pixels big.
*/
void myinit(void)
{
glEnable (GL_POINT_SMOOTH);
glEnable (GL_BLEND);
glBlendFunc (GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
glHint (GL_POINT_SMOOTH_HINT, GL_DONT_CARE);
glPointSize (3.0);

glClearColor(0.0, 0.0, 0.0, 0.0);
}

/* display() draws several points.
*/
void CALLBACK display(void)
{
int i;

glClear (GL_COLOR_BUFFER_BIT);
glColor4f (1.0, 1.0, 1.0, 1.0);
glBegin (GL_POINTS);
for (i = 1; i < 10; i++) {
glVertex2f ((GLfloat) i * 10.0, (GLfloat) i * 10.0);
}
glEnd ();
glFlush();
}

void CALLBACK myReshape(GLsizei w, GLsizei h)
{
if (!h) return;
glViewport(0, 0, w, h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w < h)
glOrtho (0.0, 100.0,
0.0, 100.0*(GLfloat) h/(GLfloat) w, -1.0, 1.0);
else
glOrtho (0.0, 100.0*(GLfloat) w/(GLfloat) h,
0.0, 100.0, -1.0, 1.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity ();
}

/* Main Loop
* Open window with initial window size, title bar,
* RGBA display mode, and handle input events.
*/
int main(int argc, char** argv)
{
auxInitDisplayMode (AUX_SINGLE | AUX_RGB);
auxInitPosition (0, 0, 100, 100);
auxInitWindow ("Points");
myinit();
auxReshapeFunc (myReshape);
auxMainLoop(display);
return(0);
}