Implement texture locking

CMakeLists.txt

@@ -52,6 +52,7 @@ SET(LIBRARY_SOURCES
 	SDL2pp/Renderer.cc
 	SDL2pp/SDL.cc
 	SDL2pp/Texture.cc
+	SDL2pp/TextureLock.cc
 	SDL2pp/Window.cc
 )
 

SDL2pp/Texture.cc

@@ -94,4 +94,8 @@ void Texture::SetColorMod(Uint8 r, Uint8 g, Uint8 b) {
 		throw Exception("SDL_SetTextureColorMod failed");
 }
 
+Texture::LockHandle Texture::Lock(const Rect& rect) {
+	return LockHandle(this, rect);
+}
+
 }

SDL2pp/Texture.hh

@@ -41,6 +41,30 @@ class Texture {
 private:
 	SDL_Texture* texture_;
 
+public:
+	class LockHandle {
+		friend class Texture;
+	private:
+		Texture* texture_;
+		void* pixels_;
+		int pitch_;
+
+	private:
+		LockHandle(Texture* texture, const Rect& rect);
+
+	public:
+		~LockHandle();
+
+		LockHandle(LockHandle&& other) noexcept;
+		LockHandle& operator=(LockHandle&& other) noexcept;
+
+		LockHandle(const LockHandle& other) = delete;
+		LockHandle& operator=(const LockHandle& other) = delete;
+
+		void* GetPixels() const;
+		int GetPitch() const;
+	};
+
 public:
 	Texture(Renderer& renderer, Uint32 format, int access, int w, int h);
 #ifdef SDL2PP_WITH_IMAGE
@@ -61,6 +85,8 @@ public:
 	void SetBlendMode(SDL_BlendMode blendMode);
 	void SetAlphaMod(Uint8 alpha = 255);
 	void SetColorMod(Uint8 r = 255, Uint8 g = 255, Uint8 b = 255);
+
+	LockHandle Lock(const Rect& rect);
 };
 
 }

SDL2pp/TextureLock.cc

@@ -0,0 +1,63 @@
+/*
+  libSDL2pp - C++ wrapper for libSDL2
+  Copyright (C) 2013 Dmitry Marakasov <amdmi3@amdmi3.ru>
+
+  This software is provided 'as-is', without any express or implied
+  warranty.  In no event will the authors be held liable for any damages
+  arising from the use of this software.
+
+  Permission is granted to anyone to use this software for any purpose,
+  including commercial applications, and to alter it and redistribute it
+  freely, subject to the following restrictions:
+
+  1. The origin of this software must not be misrepresented; you must not
+     claim that you wrote the original software. If you use this software
+     in a product, an acknowledgment in the product documentation would be
+     appreciated but is not required.
+  2. Altered source versions must be plainly marked as such, and must not be
+     misrepresented as being the original software.
+  3. This notice may not be removed or altered from any source distribution.
+*/
+
+#include <SDL2/SDL_render.h>
+
+#include <SDL2pp/Exception.hh>
+#include <SDL2pp/Rect.hh>
+
+#include <SDL2pp/Texture.hh>
+
+namespace SDL2pp {
+
+Texture::LockHandle::LockHandle(Texture* texture, const Rect& rect) : texture_(texture) {
+	if (SDL_LockTexture(texture_->Get(), rect.Get(), &pixels_, &pitch_) != 0)
+		throw Exception("SDL_LockTexture failed");
+}
+
+Texture::LockHandle::LockHandle(Texture::LockHandle&& other) noexcept : texture_(other.texture_), pixels_(other.pixels_), pitch_(other.pitch_) {
+	other.texture_ = nullptr;
+}
+
+Texture::LockHandle& Texture::LockHandle::operator=(Texture::LockHandle&& other) noexcept {
+	texture_ = other.texture_;
+	pixels_ = other.pixels_;
+	pitch_ = other.pitch_;
+
+	other.texture_ = nullptr;
+
+	return *this;
+}
+
+Texture::LockHandle::~LockHandle() {
+	if (texture_ != nullptr)
+		SDL_UnlockTexture(texture_->Get());
+}
+
+void* Texture::LockHandle::GetPixels() const {
+	return pixels_;
+}
+
+int Texture::LockHandle::GetPitch() const {
+	return pitch_;
+}
+
+}