single.c

OpeNGL超级宝典源代码. OpeNGL超级宝典源代码.

// Scissor.c
// OpenGL SuperBible, 3rd Edition
// Richard S. Wright Jr.
// [e-mail]

#include "../../Common/OpenGLSB.h"	// System and OpenGL Stuff
#include <math.h>
	
///////////////////////////////////////////////////////////
// Called to draw scene
void RenderScene(void)
	{
        static GLdouble dRadius = 0.1;
        static GLdouble dAngle = 0.0;
        
        // Clear blue window
        glClearColor(0.0f, 0.0f, 1.0f, 0.0f);
        
        if(dAngle == 0.0)
            glClear(GL_COLOR_BUFFER_BIT);
                
        glBegin(GL_POINTS);
            glVertex2d(dRadius * cos(dAngle), dRadius * sin(dAngle));
        glEnd();
        
        dRadius *= 1.01;
        dAngle += 0.1;
        
        if(dAngle > 30.0)
            {
            dRadius = 0.1;
            dAngle = 0.0;
            }
        
        glFlush();
        }

///////////////////////////////////////////////////////////
// Trigger a repaint
void Timer(int value)
    {
    glutTimerFunc(50,Timer, 0);
    glutPostRedisplay();
    }


///////////////////////////////////////////////////////////
// Set viewport and projection
void ChangeSize(int w, int h)
	{
	// Prevent a divide by zero
	if(h == 0)
		h = 1;

	// Set Viewport to window dimensions
        glViewport(0, 0, w, h);


	// Set the perspective coordinate system
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();

	// Set 2D Coordinate system
	gluOrtho2D(-4.0, 4.0, -3.0, 3.0);

	// Modelview matrix reset
	glMatrixMode(GL_MODELVIEW);
	glLoadIdentity();
	}


///////////////////////////////////////////////////////////
// Program entry point
int main(int argc, char* argv[])
	{
	glutInit(&argc, argv);
	glutInitDisplayMode(GLUT_RGB);
	glutInitWindowSize(800,600);
	glutCreateWindow("OpenGL Single Buffered");
	glutReshapeFunc(ChangeSize);
	glutDisplayFunc(RenderScene);
        glutTimerFunc(50,Timer, 0);
        glutMainLoop();

	return 0;
	}