Drawing graphics with 3D enhancement tips (v)----polygon elements use and more

1. Note that polygons in polygon elements can only be planar and must be convex, and the edges of the polygons cannot be bent

2. Segmentation and boundaries, which can be artificially set for boundary and non-boundary edges

Gledgeflag (TRUE)//Next all points are boundary edge beginnings

Gledgeflag (FALSE)//Next all points are non-boundary edge start

3. Manipulating depth buffers

Glutinitdispalymode (glut_depth);//Open Depth buffer

Glenable (gl_depth_test);//enable depth test, even if not enabled, the depth value is still written to the depth buffer, but not tested

Gldepthmask (gl_false/gl_true);//gl_false: No further write depth value, but written to allow deep testing
4. Render Area Clipping

You can render only within the specified cropping area

Glenable (gl_scissor_test);

Glscissor (X,y,width,height);

Drawing graphics with 3D enhancement tips (v)----polygon elements use and more