package iron.culling;

class OccluderProxy {

	public var positions: kha.arrays.Float32Array;
	public var indices: kha.arrays.Uint32Array;
	public var triangleCount: Int;
	public var meshUid: Int;

	var worldPositions: kha.arrays.Float32Array;
	var mvp: iron.math.Mat4;

	public function new() {
		indices = new kha.arrays.Uint32Array(0);
		triangleCount = 0;
	}

	public function setData(pos: kha.arrays.Float32Array, idx: kha.arrays.Uint32Array, uid: Int) {
		#if js
		if (!Std.isOfType(pos, js.lib.DataView)) {
			var srcF: Array<Float> = cast pos;
			var dstF = new kha.arrays.Float32Array(srcF.length);
			for (i in 0...srcF.length) dstF[i] = srcF[i];
			pos = dstF;
		}
		if (!Std.isOfType(idx, js.lib.DataView)) {
			var srcI: Array<Int> = cast idx;
			var dstI = new kha.arrays.Uint32Array(srcI.length);
			for (i in 0...srcI.length) dstI[i] = srcI[i];
			idx = dstI;
		}
		#end
		positions = pos;
		indices = idx;
		triangleCount = Std.int(idx.length / 3);
		meshUid = uid;
	}

	public function rasterize(
		rasterizer: SoftwareOcclusionRasterizer,
		world: iron.math.Mat4,
		vp: iron.math.Mat4,
		screenW: Int, screenH: Int
	) {
		if (positions == null || indices == null || triangleCount == 0) return;

		var vertCount = Std.int(positions.length / 3);

		var clipSize = vertCount * 4;
		if (worldPositions == null || worldPositions.length < clipSize) {
			worldPositions = new kha.arrays.Float32Array(clipSize);
		}

		if (mvp == null) mvp = iron.math.Mat4.identity();
		mvp.multmats(vp, world);

		for (i in 0...vertCount) {
			var x = positions[i * 3];
			var y = positions[i * 3 + 1];
			var z = positions[i * 3 + 2];
			var off = i * 4;
			worldPositions[off]     = mvp._00 * x + mvp._10 * y + mvp._20 * z + mvp._30;
			worldPositions[off + 1] = mvp._01 * x + mvp._11 * y + mvp._21 * z + mvp._31;
			worldPositions[off + 2] = mvp._02 * x + mvp._12 * y + mvp._22 * z + mvp._32;
			worldPositions[off + 3] = mvp._03 * x + mvp._13 * y + mvp._23 * z + mvp._33;
		}

		rasterizer.rasterizeProxyTransformed(worldPositions, indices, screenW, screenH);
	}

}