Method WaverBlit

src/bitmap.cpp:706–740

}

void Bitmap::WaverBlit(int x, int y, double zoom_x, double zoom_y, Bitmap const& src, Rect const& src_rect, int depth, double phase, Opacity const& opacity, Bitmap::BlendMode blend_mode) {
	if (opacity.IsTransparent()) {
		return;
	}

	Transform xform = Transform::Scale(1.0 / zoom_x, 1.0 / zoom_y);

	pixman_image_set_transform(src.bitmap.get(), &xform.matrix);

	auto mask = CreateMask(opacity, src_rect, &xform);

	int height = static_cast<int>(std::floor(src_rect.height * zoom_y));
	int width  = static_cast<int>(std::floor(src_rect.width * zoom_x));
	const auto xoff = src_rect.x * zoom_x;
	const auto yoff = src_rect.y * zoom_y;
	const auto yclip = y < 0 ? -y : 0;
	const auto yend = std::min(height, this->height() - y);
	for (int i = yclip; i < yend; i++) {
		int dy = y + i;
		// RPG_RT starts the effect from the top of the screen even if the image is clipped. The result
		// is that moving images which cross the top of the screen can appear to go too fast or too slow
		// in RPT_RT. The (i - yclip) is RPG_RT compatible behavior. Just (i) would be more correct.
		const double sy = (i - yclip) * (2 * M_PI) / (32.0 * zoom_y);
		const int offset = 2 * zoom_x * depth * std::sin(phase + sy);

		pixman_image_composite32(src.GetOperator(mask.get(), blend_mode),
								 src.bitmap.get(), mask.get(), bitmap.get(),
								 xoff, yoff + i,
								 0, i,
								 x + offset, dy,
								 width, 1);
	}

	pixman_image_set_transform(src.bitmap.get(), nullptr);
}

static pixman_color_t PixmanColor(const Color &color) {
	pixman_color_t pcolor;