function WebGLIndexedBufferRenderer( gl, extensions, info ) {
let mode;
function setMode( value ) {
mode = value;
}
let type, bytesPerElement;
function setIndex( value ) {
type = value.type;
bytesPerElement = value.bytesPerElement;
}
function render( start, count ) {
gl.drawElements( mode, count, type, start * bytesPerElement );
info.update( count, mode, 1 );
}
function renderInstances( start, count, primcount ) {
if ( primcount === 0 ) return;
gl.drawElementsInstanced( mode, count, type, start * bytesPerElement, primcount );
info.update( count, mode, primcount );
}
function renderMultiDraw( starts, counts, drawCount ) {
if ( drawCount === 0 ) return;
const extension = extensions.get( 'WEBGL_multi_draw' );
extension.multiDrawElementsWEBGL( mode, counts, 0, type, starts, 0, drawCount );
let elementCount = 0;
for ( let i = 0; i < drawCount; i ++ ) {
elementCount += counts[ i ];
}
info.update( elementCount, mode, 1 );
}
function renderMultiDrawInstances( starts, counts, drawCount, primcount ) {
if ( drawCount === 0 ) return;
const extension = extensions.get( 'WEBGL_multi_draw' );
if ( extension === null ) {
for ( let i = 0; i < starts.length; i ++ ) {
renderInstances( starts[ i ] / bytesPerElement, counts[ i ], primcount[ i ] );
}
} else {
extension.multiDrawElementsInstancedWEBGL( mode, counts, 0, type, starts, 0, primcount, 0, drawCount );
let elementCount = 0;
for ( let i = 0; i < drawCount; i ++ ) {
elementCount += counts[ i ] * primcount[ i ];
}
info.update( elementCount, mode, 1 );
}
}
//
this.setMode = setMode;
this.setIndex = setIndex;
this.render = render;
this.renderInstances = renderInstances;
this.renderMultiDraw = renderMultiDraw;
this.renderMultiDrawInstances = renderMultiDrawInstances;
}
export { WebGLIndexedBufferRenderer };