diff options
| -rw-r--r-- | progs/trivial/tri-point-line-clipped.c | 35 |
1 files changed, 30 insertions, 5 deletions
diff --git a/progs/trivial/tri-point-line-clipped.c b/progs/trivial/tri-point-line-clipped.c index eef926c24c7..f8c1015f5f4 100644 --- a/progs/trivial/tri-point-line-clipped.c +++ b/progs/trivial/tri-point-line-clipped.c @@ -1,5 +1,10 @@ /** - * Test frustum clipping w/ glPolygonMode LINE/POINT. + * Test frustum/user clipping w/ glPolygonMode LINE/POINT. + * + * The bottom/left and bottom/right verts are outside the frustum and clipped. + * The top vertex is clipped by a user clipping plane. + * + * A filled gray reference triangle is shown underneath the points/lines. */ #include <stdio.h> @@ -11,7 +16,7 @@ static int win; static void -Tri(void) +ColorTri(void) { glBegin(GL_TRIANGLES); glColor3f(1, 0, 0); glVertex3f(-1.5, -0.8, 0.0); @@ -22,18 +27,38 @@ Tri(void) static void +GrayTri(void) +{ + glColor3f(0.3, 0.3, 0.3); + glBegin(GL_TRIANGLES); + glVertex3f(-1.5, -0.8, 0.0); + glVertex3f( 1.5, -0.8, 0.0); + glVertex3f( 0.0, 0.9, 0.0); + glEnd(); +} + + +static void Draw(void) { + static const GLdouble plane[4] = { 0, -1.0, 0, 0.5 }; + + glClear(GL_COLOR_BUFFER_BIT); + glPointSize(13.0); glLineWidth(5.0); - glClear(GL_COLOR_BUFFER_BIT); + glClipPlane(GL_CLIP_PLANE0, plane); + glEnable(GL_CLIP_PLANE0); + + glPolygonMode(GL_FRONT_AND_BACK, GL_FILL); + GrayTri(); glPolygonMode(GL_FRONT_AND_BACK, GL_LINE); - Tri(); + ColorTri(); glPolygonMode(GL_FRONT_AND_BACK, GL_POINT); - Tri(); + ColorTri(); glutSwapBuffers(); } |