1 files changed, 110 insertions, 0 deletions
diff --git a/mwe/resource-manager/map_layer.cpp b/mwe/resource-manager/map_layer.cpp
new file mode 100644
index 0000000..6339707
--- /dev/null
+++ b/mwe/resource-manager/map_layer.cpp
@@ -0,0 +1,110 @@
+
+
+#include "map_layer.h"
+#include "TextureMap.h"
+#include <tmxlite/Layer.hpp>
+#include <tmxlite/TileLayer.hpp>
+
+MapLayer::MapLayer() {}
+
+MapLayer::~MapLayer() { m_subsets.clear(); }
+
+bool MapLayer::create(const tmx::Map & map, std::uint32_t layerIndex,
+					  const std::vector<TextureMap *> & textures) {
+	const auto & layers = map.getLayers();
+	assert(layers[layerIndex]->getType() == tmx::Layer::Type::Tile);
+
+	const auto & layer = layers[layerIndex]->getLayerAs<tmx::TileLayer>();
+	const auto mapSize = map.getTileCount();
+	const auto mapTileSize = map.getTileSize();
+	const auto & tileSets = map.getTilesets();
+
+	const auto tintColour = layer.getTintColour();
+	const SDL_Colour vertColour
+		= {tintColour.r, tintColour.g, tintColour.b, tintColour.a};
+
+	for (auto i = 0u; i < tileSets.size(); ++i) {
+		//check tile ID to see if it falls within the current tile set
+		const auto & ts = tileSets[i];
+		const auto & tileIDs = layer.getTiles();
+
+		const auto texSize = textures[i]->getSize();
+		const auto tileCountX = texSize.x / mapTileSize.x;
+		const auto tileCountY = texSize.y / mapTileSize.y;
+
+		const float uNorm = static_cast<float>(mapTileSize.x) / texSize.x;
+		const float vNorm = static_cast<float>(mapTileSize.y) / texSize.y;
+
+		std::vector<SDL_Vertex> verts;
+		for (auto y = 0u; y < mapSize.y; ++y) {
+			for (auto x = 0u; x < mapSize.x; ++x) {
+				const auto idx = y * mapSize.x + x;
+				if (idx < tileIDs.size() && tileIDs[idx].ID >= ts.getFirstGID()
+					&& tileIDs[idx].ID
+						   < (ts.getFirstGID() + ts.getTileCount())) {
+					//tex coords
+					auto idIndex = (tileIDs[idx].ID - ts.getFirstGID());
+					float u = static_cast<float>(idIndex % tileCountX);
+					float v = static_cast<float>(idIndex / tileCountY);
+					u *= mapTileSize
+							 .x; //TODO we should be using the tile set size, as this may be different from the map's grid size
+					v *= mapTileSize.y;
+
+					//normalise the UV
+					u /= textures[i]->getSize().x;
+					v /= textures[i]->getSize().y;
+
+					//vert pos
+					const float tilePosX
+						= static_cast<float>(x) * mapTileSize.x;
+					const float tilePosY
+						= (static_cast<float>(y) * mapTileSize.y);
+
+					//push back to vert array
+					SDL_Vertex vert
+						= {{tilePosX, tilePosY}, vertColour, {u, v}};
+					verts.emplace_back(vert);
+					vert = {{tilePosX + mapTileSize.x, tilePosY},
+							vertColour,
+							{u + uNorm, v}};
+					verts.emplace_back(vert);
+					vert = {{tilePosX, tilePosY + mapTileSize.y},
+							vertColour,
+							{u, v + vNorm}};
+					verts.emplace_back(vert);
+
+					vert = {{tilePosX, tilePosY + mapTileSize.y},
+							vertColour,
+							{u, v + vNorm}};
+					verts.emplace_back(vert);
+					vert = {{tilePosX + mapTileSize.x, tilePosY},
+							vertColour,
+							{u + uNorm, v}};
+					verts.emplace_back(vert);
+					vert
+						= {{tilePosX + mapTileSize.x, tilePosY + mapTileSize.y},
+						   vertColour,
+						   {u + uNorm, v + vNorm}};
+					verts.emplace_back(vert);
+				}
+			}
+		}
+
+		if (!verts.empty()) {
+			m_subsets.emplace_back();
+			m_subsets.back().texture = *textures[i];
+			m_subsets.back().vertexData.swap(verts);
+		}
+	}
+
+	return true;
+}
+
+void MapLayer::draw(SDL_Renderer * renderer) const {
+	assert(renderer);
+	for (const auto & s : m_subsets) {
+		SDL_RenderGeometry(renderer, s.texture, s.vertexData.data(),
+						   static_cast<std::int32_t>(s.vertexData.size()),
+						   nullptr, 0);
+	}
+}