Button is being drawn, if a little jenky; needs SDL2_ttf

I tweaked the Image::Create() implementation, to act as a render target.

src/application.cpp

@@ -57,6 +57,13 @@ void Application::Init(int argc, char* argv[]) {
 	//set the hook for the renderer
 	BaseScene::SetRenderer(renderer);
 
+	//setting up SDL2_ttf
+	if (TTF_Init()) {
+		std::ostringstream msg;
+		msg << "Failed to initialize SDL2_ttf: " << SDL_GetError();
+		throw(std::runtime_error(msg.str()));
+	}
+
 	//setup lua
 	lua = luaL_newstate();
 	if (!lua) {
@@ -118,6 +125,7 @@ void Application::Proc() {
 
 void Application::Quit() {
 	lua_close(lua);
+	TTF_Quit();
 
 	//clean up after the program
 	BaseScene::SetRenderer(nullptr);

src/application.hpp

@@ -26,6 +26,7 @@
 
 #include "lua.hpp"
 #include "SDL2/SDL.h"
+#include "SDL2/SDL_ttf.h"
 
 //TODO: do something with these
 constexpr int screenWidth = 800;

src/common/button.cpp

@@ -0,0 +1,106 @@
+/* Copyright: (c) Kayne Ruse 2013-2015
+ * 
+ * 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 "button.hpp"
+
+#include <stdexcept>
+
+void Button::DrawTo(SDL_Renderer* renderer) {
+	image.DrawTo(renderer, 0, 0);
+}
+
+void Button::SetBackgroundTexture(SDL_Renderer* renderer, SDL_Texture* texture) {
+	//copy the given texture
+	image.Free();
+
+	//a blank texture can simply free the image
+	if (!texture) {
+		return;
+	}
+
+	//get the w & h, & create
+	int w = 0, h = 0;
+	SDL_QueryTexture(texture, nullptr, nullptr, &w, &h);
+	image.Create(renderer, w, h);
+
+	//copy
+	SDL_SetRenderTarget(renderer, image.GetTexture());
+	SDL_RenderCopy(renderer, texture, nullptr, nullptr);
+	SDL_SetRenderTarget(renderer, nullptr);
+}
+
+void Button::SetText(SDL_Renderer* renderer, TTF_Font* font, std::string s, SDL_Color color) {
+	//make the surface (from SDL_ttf)
+	SDL_Surface* surf = TTF_RenderText_Solid(font, s.c_str(), color);
+	if (!surf) {
+		throw(std::runtime_error("Failed to create a TTF surface"));
+	}
+
+	//convert to texture
+	SDL_Texture* text = SDL_CreateTextureFromSurface(renderer, surf);
+	SDL_FreeSurface(surf);
+	if (!text) {
+		throw(std::runtime_error("Failed to create a TTF texture"));
+	}
+	int w, h;
+	SDL_QueryTexture(text, nullptr, nullptr, &w, &h);
+
+	//draw the text to the background
+	SDL_Rect src = {0, 0, w, h};
+	SDL_Rect dst = {
+		(image.GetClipW() - w) / 2,
+		(image.GetClipH() - h) / 2,
+		w, h};
+	SDL_SetRenderTarget(renderer, image.GetTexture());
+	SDL_RenderCopy(renderer, text, &src, &dst);
+	SDL_SetRenderTarget(renderer, nullptr);
+
+	//free the texture
+	SDL_DestroyTexture(text);
+}
+
+void Button::SetX(int x) {
+	posX = x;
+}
+
+void Button::SetY(int y) {
+	posY = y;
+}
+
+void Button::MouseMotion(SDL_MouseMotionEvent const&) {
+	//TODO: empty
+}
+
+void Button::MouseButtonDown(SDL_MouseButtonEvent const&) {
+	//TODO: empty
+}
+
+void Button::MouseButtonUp(SDL_MouseButtonEvent const&) {
+	//TODO: empty
+}
+
+void Button::SetOnPress(fptr arg) {
+	onPress = arg;
+}
+
+void Button::SetOnRelease(fptr arg) {
+	onRelease = arg;
+}

src/common/button.hpp

@@ -0,0 +1,61 @@
+/* Copyright: (c) Kayne Ruse 2013-2015
+ * 
+ * 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.
+*/
+#pragma once
+
+#include "image.hpp"
+
+#include "SDL2/SDL_ttf.h"
+
+#include <string>
+
+class Button {
+public:
+	//types
+	typedef int (*fptr)();
+
+	//methods
+	Button() = default;
+	~Button() = default;
+
+	void DrawTo(SDL_Renderer*);
+
+	//setup
+	void SetBackgroundTexture(SDL_Renderer*, SDL_Texture*);
+	void SetText(SDL_Renderer*, TTF_Font*, std::string, SDL_Color);
+	void SetX(int x);
+	void SetY(int y);
+
+	//capture input
+	void MouseMotion(SDL_MouseMotionEvent const&);
+	void MouseButtonDown(SDL_MouseButtonEvent const&);
+	void MouseButtonUp(SDL_MouseButtonEvent const&);
+
+	//responses
+	void SetOnPress(fptr);
+	void SetOnRelease(fptr);
+
+protected:
+	Image image;
+	int posX = 0, posY = 0;
+	fptr onPress = nullptr;
+	fptr onRelease = nullptr;
+};

src/common/image.cpp

@@ -101,7 +101,7 @@ SDL_Texture* Image::Create(SDL_Renderer* renderer, Uint16 w, Uint16 h) {
 	//make the texture
 	texture = SDL_CreateTexture(renderer,
 		SDL_PIXELFORMAT_RGBA8888,
-		SDL_TEXTUREACCESS_STATIC,
+		SDL_TEXTUREACCESS_TARGET,
 		w, h);
 
 	if (!texture) {

src/example_scene.cpp

@@ -23,6 +23,7 @@
 
 #include <iomanip>
 #include <iostream>
+#include <sstream>
 
 ExampleScene::ExampleScene(lua_State* L) {
 	lua = L;
@@ -46,6 +47,16 @@ ExampleScene::ExampleScene(lua_State* L) {
 	camera.x = -3000;
 	camera.y = -1500;
 	camera.scale = 0.25;
+
+	//DEBUG: testing buttons
+	font = TTF_OpenFont("/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf", 12);
+	if (!font) {
+		std::ostringstream msg;
+		msg << "Failed to load a font: " << SDL_GetError();
+		throw(std::runtime_error(msg.str()));
+	}
+	button.SetBackgroundTexture(GetRenderer(), tileSheet.GetTexture());
+	button.SetText(GetRenderer(), font, "BUTTON TEXT", {255, 255, 255, 255});
 }
 
 ExampleScene::~ExampleScene() {
@@ -73,6 +84,9 @@ void ExampleScene::RenderFrame(SDL_Renderer* renderer) {
 		//NOTE: Graphical scaling is done internally
 		tileSheet.DrawRegionTo(renderer, &(*it), camera.x, camera.y, camera.scale, camera.scale);
 	}
+
+	//DEBUG: testing UI
+	button.DrawTo(renderer);
 }
 
 //-------------------------

src/example_scene.hpp

@@ -22,10 +22,12 @@
 #pragma once
 
 #include "base_scene.hpp"
+#include "button.hpp"
 #include "region_pager_lua.hpp"
 #include "tile_sheet.hpp"
 
 #include "lua.hpp"
+#include "SDL2/SDL_ttf.h"
 
 class ExampleScene : public BaseScene {
 public:
@@ -60,4 +62,7 @@ private:
 
 	int selection = 1;
 	int layer = 0;
+
+	TTF_Font* font = nullptr;
+	Button button;
 };

src/makefile

@@ -7,7 +7,7 @@ LIBS+=libcommon.a libmap.a
 ifeq ($(OS),Windows_NT)
 	LIBS+=-lmingw32
 endif
-LIBS+=-lSDL2main -lSDL2 -lSDL2_image -llua
+LIBS+=-lSDL2main -lSDL2 -lSDL2_image -lSDL2_ttf -llua
 ifeq ($(shell uname), Linux)
 	#I don't know what this does, but Ubuntu needs it (dynamic linking for lua)
 	LIBS+=-ldl