test flat shading w/ clipping

progs/trivial/Makefile

@@ -13,6 +13,7 @@ LIBS = $(APP_LIB_DEPS)
 SOURCES = \
 	clear.c \
 	clear-scissor.c \
+	flat-clip.c \
 	fs-tri.c \
 	line-clip.c \
 	line-cull.c \

progs/trivial/flat-clip.c

@@ -0,0 +1,149 @@
+/**
+ * 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;
+}