Designing Games with Game Maker - YoYo Games

}
ttt = background_get_texture(back);
d3d_primitive_begin_texture(pr_trianglefan,ttt);
d3d_vertex_texture(0,480,0,0,0);
d3d_vertex_texture(640,480,0,1,0);
d3d_vertex_texture(640,480,1000,1,1);
d3d_vertex_texture(0,480,1000,0,1);
d3d_primitive_end();
A triangle has a front and a back side. The front side is defined to be the side where the
vertices are defined in counter-clockwise order. Normally both sides are drawn. But if you
make a closed shape this is a waste because the back side of the triangle can never be seen.
In this case you can switch on backface culling. This saves about half the amount of drawing
time but it leaves you with the task of defining your polygons in the right way. The following
function exists:
d3d_set_culling(cull) Indicates to start backface culling (true) or stop
backface culling (false).
Drawing basic shapes
A number of functions exist for drawing basic shapes, like blocks and walls. Note that these
shapes also work correctly with backface culling on.
d3d_draw_block(x1,y1,z1,x2,y2,z2,texid,hrepeat,vrepeat)
Draws a block in the current color with the indicated opposite corners using
the indicated texture. Use -1 to not use a texture. hrepeat indicates how
often the texture must be repeated along the horizontal edge of each face.
vrepeat does the same for the vertical edge.
d3d_draw_cylinder(x1,y1,z1,x2,y2,z2,texid,hrepeat,vrepeat,c
losed,steps) Draws a vertical cylinder in the current color in the indicated
bounding box using the indicated texture. Use -1 to not use a texture.
hrepeat indicates how often the texture must be repeated along the
horizontal edge of each face. vrepeat does the same for the vertical edge.
closed indicates whether to close the top and bottom of the cylinder. steps
indicates how many rotational steps must be taken. A typical value is 24.