--- /dev/null
+/**
+ * Test flat shading and clipping.
+ *
+ * Brian Paul
+ * 30 August 2007
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+#include <GL/glut.h>
+
+static int Win;
+static GLfloat Scale = 2.0, Zrot = 50;
+static GLenum Mode = GL_LINE_LOOP;
+static GLboolean Smooth = 0;
+static GLenum PolygonMode = GL_FILL;
+
+
+static void
+Draw(void)
+{
+ glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
+
+ if (Smooth)
+ glShadeModel(GL_SMOOTH);
+ else
+ glShadeModel(GL_FLAT);
+
+ glPushMatrix();
+ glScalef(Scale, Scale, 1);
+ glRotatef(Zrot, 0, 0, 1);
+
+ glPolygonMode(GL_FRONT_AND_BACK, PolygonMode);
+
+ glBegin(Mode);
+ glColor3f(1, 0, 0);
+ glVertex2f(-1, -1);
+ glColor3f(0, 1, 0);
+ glVertex2f( 2, -1);
+ glColor3f(0, 0, 1);
+ glVertex2f( 0, 1);
+ glEnd();
+
+ glPushMatrix();
+ glScalef(0.9, 0.9, 1);
+ glBegin(Mode);
+ glColor3f(1, 0, 0);
+ glVertex2f( 0, 1);
+
+ glColor3f(0, 0, 1);
+ glVertex2f( 2, -1);
+
+ glColor3f(0, 1, 0);
+ glVertex2f(-1, -1);
+
+ glEnd();
+ glPopMatrix();
+
+ glPopMatrix();
+
+ glutSwapBuffers();
+}
+
+
+static void
+Reshape(int width, int height)
+{
+ glViewport(0, 0, width, height);
+ glMatrixMode(GL_PROJECTION);
+ glLoadIdentity();
+ glFrustum(-1.0, 1.0, -1.0, 1.0, 5.0, 25.0);
+ glMatrixMode(GL_MODELVIEW);
+ glLoadIdentity();
+ glTranslatef(0.0, 0.0, -15.0);
+}
+
+
+static void
+Key(unsigned char key, int x, int y)
+{
+ (void) x;
+ (void) y;
+ switch (key) {
+ case 'p':
+ if (Mode == GL_TRIANGLES)
+ Mode = GL_LINE_LOOP;
+ else
+ Mode = GL_TRIANGLES;
+ break;
+ case 'f':
+ if (PolygonMode == GL_POINT)
+ PolygonMode = GL_LINE;
+ else if (PolygonMode == GL_LINE)
+ PolygonMode = GL_FILL;
+ else
+ PolygonMode = GL_POINT;
+ printf("PolygonMode = 0x%x\n", PolygonMode);
+ break;
+ case 'r':
+ Zrot -= 5.0;
+ break;
+ case 'R':
+ Zrot += 5.0;
+ break;
+ case 'z':
+ Scale *= 1.1;
+ break;
+ case 'Z':
+ Scale /= 1.1;
+ break;
+ case 's':
+ Smooth = !Smooth;
+ break;
+ case 27:
+ glutDestroyWindow(Win);
+ exit(0);
+ break;
+ }
+ glutPostRedisplay();
+}
+
+
+static void
+Init(void)
+{
+ printf("Usage:\n");
+ printf(" z/Z: change triangle size\n");
+ printf(" r/R: rotate\n");
+ printf(" p: toggle line/fill mode\n");
+}
+
+
+int
+main(int argc, char *argv[])
+{
+ glutInit(&argc, argv);
+ glutInitWindowPosition(0, 0);
+ glutInitWindowSize(400, 400);
+ glutInitDisplayMode(GLUT_RGB | GLUT_DOUBLE | GLUT_DEPTH);
+ Win = glutCreateWindow(argv[0]);
+ glutReshapeFunc(Reshape);
+ glutKeyboardFunc(Key);
+ glutDisplayFunc(Draw);
+ Init();
+ glutMainLoop();
+ return 0;
+}