add Layer::loadPNG (aea90821) · Commits · github_fork / Clip

src/signaltk/core/layer.cc

+29 −2

Original line number	Diff line number	Diff line
		@@ -12,6 +12,8 @@

		namespace signaltk {

		Layer::Layer() : width(0), height(0), surface(nullptr), ctx(nullptr) {}

		Layer::Layer(
		uint32_t w,
		uint32_t h) :
		@@ -32,8 +34,33 @@ void Layer::clear(const Colour& c) {
		cairo_fill(ctx);
		}

		void Layer::writePNG(const char* path) {
		cairo_surface_write_to_png(surface, path);
		bool Layer::loadPNG(const char* path) {
		if (surface \|\| ctx) {
		return false;
		}

		surface = cairo_image_surface_create_from_png(path);
		if (cairo_surface_status(surface) != CAIRO_STATUS_SUCCESS) {
		return false;
		}

		ctx = cairo_create(surface);

		double extent[4];
		cairo_clip_extents(ctx, extent + 0, extent + 1, extent + 2, extent + 3);
		width = extent[2] - extent[0];
		height = extent[3] - extent[1];

		return true;
		}

		bool Layer::writePNG(const char* path) const {
		if (!surface \|\| !ctx) {
		return false;
		}

		auto rc = cairo_surface_write_to_png(surface, path);
		return rc == CAIRO_STATUS_SUCCESS;
		}

		} // namespace signaltk

+5 −3

Original line number	Diff line number	Diff line
		@@ -18,17 +18,19 @@
		namespace signaltk {

		struct Layer {
		Layer();
		Layer(uint32_t width, uint32_t height);
		~Layer();
		Layer(const Layer&) = delete;
		Layer& operator=(const Layer&) = delete;

		void writePNG(const char* path);
		bool loadPNG(const char* path);
		bool writePNG(const char* path) const;

		void clear(const Colour& c);

		const uint32_t width;
		const uint32_t height;
		uint32_t width;
		uint32_t height;
		cairo_surface_t* surface;
		cairo_t* ctx;
		};