Object Occlusion Culling

leenkx/Sources/iron/culling/ContributionCull.hx

@@ -0,0 +1,62 @@
+package iron.culling;
+
+class ContributionCull {
+
+	public static var minPixelRadius: Float = 2.0;
+	public static var enabled: Bool = false;
+
+	public static function passes(
+		centerX: Float, centerY: Float, centerZ: Float,
+		radius: Float,
+		camX: Float, camY: Float, camZ: Float,
+		focalLengthPx: Float
+	): Bool {
+		if (!enabled || minPixelRadius <= 0.0 || focalLengthPx <= 0.0) return true;
+
+		var dx = centerX - camX;
+		var dy = centerY - camY;
+		var dz = centerZ - camZ;
+		var dist = Math.sqrt(dx * dx + dy * dy + dz * dz);
+
+		if (dist <= radius) return true; 
+
+		var projectedRadiusPx = focalLengthPx * radius / dist;
+		return projectedRadiusPx >= minPixelRadius;
+	}
+
+	public static function passesNode(
+		node: BVHNode,
+		camX: Float, camY: Float, camZ: Float,
+		focalLengthPx: Float
+	): Bool {
+		if (!enabled || minPixelRadius <= 0.0 || focalLengthPx <= 0.0) return true;
+
+		var cx = (node.minX + node.maxX) * 0.5;
+		var cy = (node.minY + node.maxY) * 0.5;
+		var cz = (node.minZ + node.maxZ) * 0.5;
+		var ex = (node.maxX - node.minX) * 0.5;
+		var ey = (node.maxY - node.minY) * 0.5;
+		var ez = (node.maxZ - node.minZ) * 0.5;
+		var radius = Math.sqrt(ex * ex + ey * ey + ez * ez);
+
+		if (camX >= node.minX && camX <= node.maxX &&
+			camY >= node.minY && camY <= node.maxY &&
+			camZ >= node.minZ && camZ <= node.maxZ) {
+			return true;
+		}
+
+		var dx = cx - camX;
+		var dy = cy - camY;
+		var dz = cz - camZ;
+		var dist = Math.sqrt(dx * dx + dy * dy + dz * dz);
+
+		if (dist <= radius) return true;
+
+		var projectedRadiusPx = focalLengthPx * radius / dist;
+		return projectedRadiusPx >= minPixelRadius;
+	}
+
+	public static function computeFocalLengthPx(fov: Float, screenHeight: Int): Float {
+		return screenHeight / (2.0 * Math.tan(fov * 0.5));
+	}
+}