diff options
-rw-r--r-- | progs/trivial/quad-clip-nearplane.c | 43 |
1 files changed, 28 insertions, 15 deletions
diff --git a/progs/trivial/quad-clip-nearplane.c b/progs/trivial/quad-clip-nearplane.c index 7e12e58a19..be9b9c619a 100644 --- a/progs/trivial/quad-clip-nearplane.c +++ b/progs/trivial/quad-clip-nearplane.c @@ -33,6 +33,7 @@ GLenum doubleBuffer; +float Z = -6; static void Init(void) { @@ -40,30 +41,36 @@ static void Init(void) fprintf(stderr, "GL_VERSION = %s\n", (char *) glGetString(GL_VERSION)); fprintf(stderr, "GL_VENDOR = %s\n", (char *) glGetString(GL_VENDOR)); - glClearColor(0.0, 0.0, 1.0, 0.0); + fprintf(stderr, "Press z/Z to translate quad\n"); + + glClearColor(0.0, 0.0, 1.0, 0.0); } static void Reshape(int width, int height) { - glViewport(0, 0, (GLint)width, (GLint)height); glMatrixMode(GL_PROJECTION); glLoadIdentity(); - glOrtho(-1.0, 1.0, -1.0, 1.0, -0.5, 1000.0); + glFrustum(-1.0, 1.0, -1.0, 1.0, 5, 100.0); glMatrixMode(GL_MODELVIEW); } static void Key(unsigned char key, int x, int y) { - switch (key) { - case 27: - exit(1); - default: - return; + case 'z': + Z += 0.5; + break; + case 'Z': + Z -= 0.5; + break; + case 27: + exit(1); + default: + return; } - + printf("Z = %f\n", Z); glutPostRedisplay(); } @@ -71,17 +78,22 @@ static void Draw(void) { glClear(GL_COLOR_BUFFER_BIT); + glPushMatrix(); + glTranslatef(0, -0.5, Z); + glBegin(GL_QUADS); glColor3f(1,0,0); - glVertex3f( 0.9, -0.9, 30.0); + glVertex3f( -0.8, 0, -4.0); glColor3f(1,1,0); - glVertex3f( 0.9, 0.9, 30.0); + glVertex3f( 0.8, 0, -4.0); glColor3f(1,0,1); - glVertex3f(-1.9, 0.9, 30.0); + glVertex3f( 0.8, 0, 4.0); glColor3f(0,1,1); - glVertex3f(-1.9, -0.9, -30.0); + glVertex3f( -0.8, 0, 4.0); glEnd(); + glPopMatrix(); + glFlush(); if (doubleBuffer) { @@ -118,7 +130,8 @@ int main(int argc, char **argv) exit(1); } - glutInitWindowPosition(0, 0); glutInitWindowSize( 250, 250); + glutInitWindowPosition(0, 0); + glutInitWindowSize( 250, 250); type = GLUT_RGB; type |= (doubleBuffer) ? GLUT_DOUBLE : GLUT_SINGLE; @@ -134,5 +147,5 @@ int main(int argc, char **argv) glutKeyboardFunc(Key); glutDisplayFunc(Draw); glutMainLoop(); - return 0; + return 0; } |