From cb8153ab83ebb422886ee4d11339e5cb1afb8aaa Mon Sep 17 00:00:00 2001
From: Dmitry Marakasov <amdmi3@amdmi3.ru>
Date: Wed, 18 Dec 2013 06:12:32 +0400
Subject: [PATCH] Add rendertarget demo

---
 CMakeLists.txt       |   1 +
 demo/rendertarget.cc | 119 +++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 120 insertions(+)
 create mode 100644 demo/rendertarget.cc

diff --git a/CMakeLists.txt b/CMakeLists.txt
index e03220f..edfc797 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -39,6 +39,7 @@ IF(CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR)
 	SET(DEMOS
 		sprites
 		lines
+		rendertarget
 	)
 
 	FOREACH(DEMO ${DEMOS})
diff --git a/demo/rendertarget.cc b/demo/rendertarget.cc
new file mode 100644
index 0000000..7147722
--- /dev/null
+++ b/demo/rendertarget.cc
@@ -0,0 +1,119 @@
+/*
+  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 <iostream>
+
+#include <SDL2/SDL.h>
+
+#include <SDL2pp/SDL2pp.hh>
+
+using namespace SDL2pp;
+
+#define RGBA(r, g, b, a) r, g, b, a
+unsigned char pixels[4 * 4 * 4] = {
+	RGBA(0xff, 0x00, 0x00, 0xff), RGBA(0xff, 0x80, 0x00, 0xff), RGBA(0xff, 0xff, 0x00, 0xff), RGBA(0x80, 0xff, 0x00, 0xff),
+	RGBA(0xff, 0x00, 0x80, 0xff), RGBA(0xff, 0xff, 0xff, 0xff), RGBA(0x00, 0x00, 0x00, 0x00), RGBA(0x00, 0xff, 0x00, 0xff),
+	RGBA(0xff, 0x00, 0xff, 0xff), RGBA(0x00, 0x00, 0x00, 0x00), RGBA(0x00, 0x00, 0x00, 0xff), RGBA(0x00, 0xff, 0x80, 0xff),
+	RGBA(0x80, 0x00, 0xff, 0xff), RGBA(0x00, 0x00, 0xff, 0xff), RGBA(0x00, 0x80, 0xff, 0xff), RGBA(0x00, 0xff, 0xff, 0xff),
+};
+
+int Run() {
+	SDL sdl(SDL_INIT_VIDEO);
+	Window window("libSDL2pp demo: sprites", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 640, 480, SDL_WINDOW_RESIZABLE);
+	Renderer render(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_TARGETTEXTURE);
+	render.SetDrawBlendMode(SDL_BLENDMODE_BLEND);
+
+	// Necessary checks according to SDL docs
+	SDL_RendererInfo ri;
+	render.GetInfo(&ri);
+
+	if (!(ri.flags & SDL_RENDERER_TARGETTEXTURE)) {
+		std::cerr << "Sorry, your renderer doesn't support texture targets" << std::endl;
+		return 1;
+	}
+
+	// Sprite data
+	Texture sprite(render, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_STATIC, 4, 4);
+
+	sprite.Update(Rect::Null(), pixels, 4 * 4);
+	sprite.SetBlendMode(SDL_BLENDMODE_BLEND);
+
+	// Two render target textures
+	Texture target1(render, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, 512, 512);
+	target1.SetBlendMode(SDL_BLENDMODE_BLEND);
+
+	Texture target2(render, SDL_PIXELFORMAT_ARGB8888, SDL_TEXTUREACCESS_TARGET, 512, 512);
+	target2.SetBlendMode(SDL_BLENDMODE_BLEND);
+
+	while (1) {
+		// Process input
+		SDL_Event event;
+		while (SDL_PollEvent(&event))
+			if (event.type == SDL_QUIT || (event.type == SDL_KEYDOWN && (event.key.keysym.sym == SDLK_ESCAPE || event.key.keysym.sym == SDLK_q)))
+				return 0;
+
+		// Note we fill with transparent color, not black
+		render.SetDrawColor(0, 0, 0, 0);
+
+		// Fill base texture with sprite texture
+		render.SetTarget(target1);
+		render.Clear();
+		render.Copy(sprite);
+
+		// Repeat several cycles of flip-flop tiling
+		for (int i = 0; i < 4; i++) {
+			render.SetTarget(target2);
+			render.Clear();
+			render.Copy(target1, Rect::Null(), Rect(0, 0, 256, 256), SDL_GetTicks() / 10000.0 * 360.0);
+			render.Copy(target1, Rect::Null(), Rect(256, 0, 256, 256), SDL_GetTicks() / 10000.0 * 360.0);
+			render.Copy(target1, Rect::Null(), Rect(0, 256, 256, 256), SDL_GetTicks() / 10000.0 * 360.0);
+			render.Copy(target1, Rect::Null(), Rect(256, 256, 256, 256), SDL_GetTicks() / 10000.0 * 360.0);
+
+			// Swap textures to copy recursively
+			target1.Swap(target2);
+		}
+
+		// Draw result to screen
+		render.SetTarget();
+		render.Clear();
+
+		render.Copy(target1, Rect::Null(), Rect(80, 0, 480, 480), SDL_GetTicks() / 10000.0 * 360.0);
+
+		render.Present();
+
+		// Frame limiter
+		SDL_Delay(1);
+	}
+
+	return 0;
+}
+
+int main() {
+	try {
+		return Run();
+	} catch (Exception& e) {
+		std::cerr << "Error: " << e.what() << " (" << e.GetSDLError() << ")" << std::endl;
+	} catch (std::exception& e) {
+		std::cerr << "Error: " << e.what() << std::endl;
+	}
+
+	return -1;
+}