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