* Add PatchManager - Allows you to patch terrain.png and items.png on the fly.

This can be used for modding, since you don't need to share copyrighted Mojang assets alongside your texture patches.

source/client/renderer/PatchManager.cpp

@@ -0,0 +1,136 @@
+#include "PatchManager.hpp"
+#include "AppPlatform.hpp"
+#include "client/common/Utils.hpp"
+#include "compat/GL.hpp"
+
+#define PM_SEPARATOR ('|')
+
+PatchManager* g_pPatchManager;
+PatchManager* GetPatchManager()
+{
+	if (!g_pPatchManager)
+		g_pPatchManager = new PatchManager;
+
+	return g_pPatchManager;
+}
+
+PatchManager::PatchManager()
+{
+	m_bGrassTinted = true;
+	m_nMetalSideYOffset = -1;
+}
+
+void PatchManager::LoadPatchData(const std::string& patchData)
+{
+	std::stringstream patchDataStream(patchData);
+	std::string currLine;
+
+	while (std::getline(patchDataStream, currLine))
+	{
+		if (currLine.empty()) continue;
+		if (currLine[0] == '#') continue;
+
+		std::string command;
+		std::stringstream lineStream(currLine);
+		// read command type
+		if (!std::getline(lineStream, command, PM_SEPARATOR))
+			continue;
+
+		if (command == "terrain" || command == "items")
+		{
+			bool bIsItems = command == "items";
+			std::string xStr, yStr, fileName;
+
+			if (!std::getline(lineStream, xStr, PM_SEPARATOR)) continue;
+			if (!std::getline(lineStream, yStr, PM_SEPARATOR)) continue;
+			if (!std::getline(lineStream, fileName, PM_SEPARATOR)) continue;
+
+			// turn the xStr and yStr into ints.
+			int x, y;
+			if (!sscanf(xStr.c_str(), "%d", &x)) continue;
+			if (!sscanf(yStr.c_str(), "%d", &y)) continue;
+
+			m_patchData.push_back(PatchData(bIsItems ? TYPE_ITEMS : TYPE_TERRAIN, x, y, fileName));
+
+			continue;
+		}
+
+		// features -- TODO un-hardcode this
+		if (command == "vegetation_tint")
+		{
+			ReadBool(lineStream, m_bGrassTinted);
+			continue;
+		}
+
+		// features -- TODO un-hardcode this
+		if (command == "metal_block_sides")
+		{
+			ReadInt(lineStream, m_nMetalSideYOffset);
+			continue;
+		}
+
+		LogMsg("Unknown command %s from patch data.", command.c_str());
+	}
+}
+
+void PatchManager::PatchTextures(AppPlatform* pAppPlatform, ePatchType patchType)
+{
+	// Use glTexSubImage2D to patch the terrain.png texture on the fly.
+	for (int i = 0; i < int(m_patchData.size()); i++)
+	{
+		PatchData& pd = m_patchData[i];
+		if (pd.m_type != patchType)
+			continue;
+
+		Texture texture = pAppPlatform->loadTexture("patches/" + pd.m_filename, true);
+		if (texture.m_width == 0)
+		{
+			LogMsg("Image %s has width 0, not found?! Skipping", pd.m_filename.c_str());
+			continue;
+		}
+
+		glTexSubImage2D(
+			GL_TEXTURE_2D,
+			0,
+			pd.m_destX,
+			pd.m_destY,
+			texture.m_width,
+			texture.m_height,
+			GL_RGBA,
+			GL_UNSIGNED_BYTE,
+			texture.m_pixels
+		);
+
+		SAFE_DELETE_ARRAY(texture.m_pixels);
+	}
+}
+
+bool PatchManager::IsGrassTinted()
+{
+	return m_bGrassTinted;
+}
+
+int PatchManager::GetMetalSideYOffset()
+{
+	return m_nMetalSideYOffset;
+}
+
+void PatchManager::ReadBool(std::istream& is, bool& b)
+{
+	std::string flag;
+	if (!std::getline(is, flag, PM_SEPARATOR))
+		return;
+
+	b = (flag == "true" || flag == "1" || flag == "TRUE");
+}
+
+void PatchManager::ReadInt(std::istream& is, int& i)
+{
+	std::string flag;
+	if (!std::getline(is, flag, PM_SEPARATOR))
+		return;
+
+	int x = -1;
+	if (sscanf(flag.c_str(), "%d", &x))
+		i = x;
+}