index-elements

Vocabulary

gpu.render

Class description

Objects of this tuple class can be passed as the indexes slot of a render-set to instruct render to assemble primitives from the active vertex-array by using an array of indexes in CPU or GPU memory.

•	The ptr slot contains a byte-array, alien, or buffer-ptr value referencing the beginning of the index array.
•	The count slot contains an integer value specifying the number of indexes to supply from the array.
•	The index-type slot contains an index-type value specifying whether the array consists of ubyte-indexes, ushort-indexes, or uint-indexes.

See also

index-range, multi-index-elements, multi-index-range

Definition

USING: math ;

IN: gpu.render

TUPLE: index-elements
    { ptr read-only } { count integer read-only initial: 0 }
    { index-type index-type read-only initial: ubyte-indexes } ;

Methods

USING: accessors gpu.buffers gpu.render gpu.render.private
kernel opengl.gl ;

M: index-elements render-vertex-indexes
    [ gl-primitive-mode ]
    [ [ count>> ] [ index-type>> gl-index-type ] [ ptr>> ] tri ]
    bi* index-buffer [ glDrawElements ] with-gpu-data-ptr ;


USING: accessors gpu.buffers gpu.render gpu.render.private
kernel opengl.gl ;

M: index-elements render-vertex-indexes-instanced
    [ gl-primitive-mode ]
    [ [ count>> ] [ index-type>> gl-index-type ] [ ptr>> ] tri ]
    [ ] tri* swap index-buffer
    [ swap glDrawElementsInstanced ] with-gpu-data-ptr ;