--- /dev/null
+/* $Id: antialias.c,v 1.1 2002/11/08 18:30:26 brianp Exp $ */
+
+/*
+ * Test multisampling and polygon smoothing.
+ *
+ * Brian Paul
+ * 4 November 2002
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/glut.h>
+
+
+static GLfloat Zrot = 0;
+static GLboolean Anim = GL_TRUE;
+static GLboolean HaveMultisample = GL_TRUE;
+
+
+static void
+PrintString(const char *s)
+{
+ while (*s) {
+ glutBitmapCharacter(GLUT_BITMAP_8_BY_13, (int) *s);
+ s++;
+ }
+}
+
+
+static void
+Polygon( GLint verts, GLfloat radius, GLfloat z )
+{
+ int i;
+ for (i = 0; i < verts; i++) {
+ float a = (i * 2.0 * 3.14159) / verts;
+ float x = radius * cos(a);
+ float y = radius * sin(a);
+ glVertex3f(x, y, z);
+ }
+}
+
+
+static void
+DrawObject( void )
+{
+ glLineWidth(3.0);
+ glColor3f(1, 1, 1);
+ glBegin(GL_LINE_LOOP);
+ Polygon(12, 1.2, 0);
+ glEnd();
+
+ glLineWidth(1.0);
+ glColor3f(1, 1, 1);
+ glBegin(GL_LINE_LOOP);
+ Polygon(12, 1.1, 0);
+ glEnd();
+
+ glColor3f(1, 0, 0);
+ glBegin(GL_POLYGON);
+ Polygon(12, 0.4, 0.3);
+ glEnd();
+
+ glColor3f(0, 1, 0);
+ glBegin(GL_POLYGON);
+ Polygon(12, 0.6, 0.2);
+ glEnd();
+
+ glColor3f(0, 0, 1);
+ glBegin(GL_POLYGON);
+ Polygon(12, 0.8, 0.1);
+ glEnd();
+
+ glColor3f(1, 1, 1);
+ glBegin(GL_POLYGON);
+ Polygon(12, 1.0, 0);
+ glEnd();
+}
+
+
+static void
+Display( void )
+{
+ glClear( GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT );
+
+ glColor3f(1, 1, 1);
+ if (HaveMultisample) {
+ glRasterPos2f(-3.1, -1.6);
+ PrintString("MULTISAMPLE");
+ }
+ glRasterPos2f(-0.8, -1.6);
+ PrintString("No antialiasing");
+ glRasterPos2f(1.6, -1.6);
+ PrintString("GL_POLYGON_SMOOTH");
+
+ /* multisample */
+ if (HaveMultisample) {
+ glEnable(GL_DEPTH_TEST);
+ glEnable(GL_MULTISAMPLE_ARB);
+ glPushMatrix();
+ glTranslatef(-2.5, 0, 0);
+ glPushMatrix();
+ glRotatef(Zrot, 0, 0, 1);
+ DrawObject();
+ glPopMatrix();
+ glPopMatrix();
+ glDisable(GL_MULTISAMPLE_ARB);
+ glDisable(GL_DEPTH_TEST);
+ }
+
+ /* non-aa */
+ glEnable(GL_DEPTH_TEST);
+ glPushMatrix();
+ glTranslatef(0, 0, 0);
+ glPushMatrix();
+ glRotatef(Zrot, 0, 0, 1);
+ DrawObject();
+ glPopMatrix();
+ glPopMatrix();
+ glDisable(GL_DEPTH_TEST);
+
+ /* polygon smooth */
+ glEnable(GL_POLYGON_SMOOTH);
+ glEnable(GL_LINE_SMOOTH);
+ glEnable(GL_BLEND);
+ glPushMatrix();
+ glTranslatef(2.5, 0, 0);
+ glPushMatrix();
+ glRotatef(Zrot, 0, 0, 1);
+ DrawObject();
+ glPopMatrix();
+ glPopMatrix();
+ glDisable(GL_LINE_SMOOTH);
+ glDisable(GL_POLYGON_SMOOTH);
+ glDisable(GL_BLEND);
+
+ glutSwapBuffers();
+}
+
+
+static void
+Reshape( int width, int height )
+{
+ GLfloat ar = (float) width / (float) height;
+ glViewport( 0, 0, width, height );
+ glMatrixMode( GL_PROJECTION );
+ glLoadIdentity();
+ glOrtho(-2.0*ar, 2.0*ar, -2.0, 2.0, -1.0, 1.0);
+ glMatrixMode( GL_MODELVIEW );
+ glLoadIdentity();
+}
+
+
+static void
+Idle( void )
+{
+ Zrot = 0.01 * glutGet(GLUT_ELAPSED_TIME);
+ glutPostRedisplay();
+}
+
+
+static void
+Key( unsigned char key, int x, int y )
+{
+ const GLfloat step = 1.0;
+ (void) x;
+ (void) y;
+ switch (key) {
+ case 'a':
+ Anim = !Anim;
+ if (Anim)
+ glutIdleFunc(Idle);
+ else
+ glutIdleFunc(NULL);
+ break;
+ case 'z':
+ Zrot = (int) (Zrot - step);
+ break;
+ case 'Z':
+ Zrot = (int) (Zrot + step);
+ break;
+ case 27:
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+Init( void )
+{
+ /* GLUT imposes the four samples/pixel requirement */
+ int s;
+ glGetIntegerv(GL_SAMPLES_ARB, &s);
+ if (!glutExtensionSupported("GL_ARB_multisample") || s < 1) {
+ printf("Warning: multisample antialiasing not supported.\n");
+ HaveMultisample = GL_FALSE;
+ }
+ printf("GL_RENDERER = %s\n", (char *) glGetString(GL_RENDERER));
+ printf("GL_SAMPLES_ARB = %d\n", s);
+
+ glBlendFunc(GL_SRC_ALPHA, GL_ONE);
+ glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+ glBlendFunc(GL_SRC_ALPHA_SATURATE, GL_ONE);
+}
+
+
+int
+main( int argc, char *argv[] )
+{
+ glutInit( &argc, argv );
+ glutInitWindowPosition( 0, 0 );
+ glutInitWindowSize( 600, 300 );
+ glutInitDisplayMode( GLUT_RGB | GLUT_ALPHA | GLUT_DOUBLE |
+ GLUT_DEPTH | GLUT_MULTISAMPLE );
+ glutCreateWindow(argv[0]);
+ glutReshapeFunc( Reshape );
+ glutKeyboardFunc( Key );
+ glutDisplayFunc( Display );
+ if (Anim)
+ glutIdleFunc( Idle );
+ Init();
+ glutMainLoop();
+ return 0;
+}