Revert most render pass API changes. The APIs need more work and iteration before they’re better to use than the old setCanvas APIs.

love.graphics.captureScreenshot has not been reverted.

--HG--
branch : minor

src/modules/graphics/opengl/wrap_Canvas.cpp

@@ -52,10 +52,61 @@ int w_Canvas_getMSAA(lua_State *L)
 	return 1;
 }
 
+int w_Canvas_renderTo(lua_State *L)
+{
+	Canvas *canvas = luax_checkcanvas(L, 1);
+	luaL_checktype(L, 2, LUA_TFUNCTION);
+
+	auto graphics = Module::getInstance<Graphics>(Module::M_GRAPHICS);
+
+	if (graphics)
+	{
+		// Save the current Canvas so we can restore it when we're done.
+		std::vector<Canvas *> oldcanvases = graphics->getCanvas();
+
+		for (Canvas *c : oldcanvases)
+			c->retain();
+
+		luax_catchexcept(L, [&](){ graphics->setCanvas(canvas); });
+
+		lua_settop(L, 2); // make sure the function is on top of the stack
+		int status = lua_pcall(L, 0, 0, 0);
+
+		graphics->setCanvas(oldcanvases);
+
+		for (Canvas *c : oldcanvases)
+			c->release();
+
+		if (status != 0)
+			return lua_error(L);
+	}
+	
+	return 0;
+}
+
+int w_Canvas_newImageData(lua_State *L)
+{
+	Canvas *canvas = luax_checkcanvas(L, 1);
+	love::image::Image *image = luax_getmodule<love::image::Image>(L, love::image::Image::type);
+	int x = (int) luaL_optnumber(L, 2, 0);
+	int y = (int) luaL_optnumber(L, 3, 0);
+	int w = (int) luaL_optnumber(L, 4, canvas->getWidth());
+	int h = (int) luaL_optnumber(L, 5, canvas->getHeight());
+
+	love::image::ImageData *img = nullptr;
+	luax_catchexcept(L, [&](){ img = canvas->newImageData(image, x, y, w, h); });
+
+	luax_pushtype(L, img);
+	img->release();
+	return 1;
+}
+
 static const luaL_Reg w_Canvas_functions[] =
 {
 	{ "getFormat", w_Canvas_getFormat },
 	{ "getMSAA", w_Canvas_getMSAA },
+	{ "renderTo", w_Canvas_renderTo },
+	{ "newImageData", w_Canvas_newImageData },
 	{ 0, 0 }
 };