basic imgui integration (now with SDL)

.gitmodules

@@ -4,3 +4,6 @@
 [submodule "third_party/PerlinNoise"]
 	path = third_party/PerlinNoise
 	url = https://github.com/Reputeless/PerlinNoise.git
+[submodule "third_party/imgui_sdl"]
+	path = third_party/imgui_sdl
+	url = https://github.com/mortie/imgui_sdl

CMakeLists.txt

@@ -1,6 +1,8 @@
 cmake_minimum_required(VERSION 3.0)
 project(swan)
 
+find_package(SDL2 REQUIRED)
+
 option(USE_CLANG_TIDY "Use clang-tidy for additional checks" ON)
 if(USE_CLANG_TIDY)
 	set(CMAKE_CXX_CLANG_TIDY
@@ -9,6 +11,7 @@ if(USE_CLANG_TIDY)
 		--checks=-*,bugprone-*,cert-*,performance-*,clang-analyzer-*,-cert-dcl16-c,-cert-err58-cpp,-clang-analyzer-optin.cplusplus.VirtualCall)
 endif()
 
+
 add_compile_options(-std=c++2a -Wall -Wextra -Wpedantic -Wno-unused-parameter)
 if(CMAKE_BUILD_TYPE STREQUAL Sanitize OR CMAKE_BUILD_TYPE STREQUAL "")
 	message(STATUS "Build mode: Sanitize")
@@ -39,7 +42,8 @@ set(libraries imgui SDL2 SDL2_image dl z)
 add_compile_options(-Wno-c99-extensions)
 
 include_directories(
-	${PROJECT_SOURCE_DIR}/third_party)
+	${PROJECT_SOURCE_DIR}/third_party
+	${SDL2_INCLUDE_DIRS})
 set(CMAKE_INSTALL_RPATH "${CMAKE_INSTALL_PREFIX}/lib;${CMAKE_INSTALL_PREFIX}/lib64;${CMAKE_INSTALL_PREFIX}/swan/libswan;${CMAKE_INSTALL_PREFIX}/swan/third_party")
 
 add_subdirectory(libswan)

libswan/include/swan/Win.h

@@ -10,7 +10,9 @@ namespace Swan {
 
 class Win {
 public:
-	Win(SDL_Window *window, SDL_Renderer *renderer): window_(window), renderer_(renderer) {
+	Win(SDL_Window *window, SDL_Renderer *renderer, float scale):
+			window_(window), renderer_(renderer), scale_(scale) {
+
 		if (SDL_GetRendererInfo(renderer_, &rinfo_) < 0) {
 			panic << "GetRenedrerInfo failed: " << SDL_GetError();
 			abort();
@@ -19,7 +21,7 @@ public:
 		// For HiDPI, we must set the renderer's logical size.
 		int w, h;
 		SDL_GetWindowSize(window_, &w, &h);
-		SDL_RenderSetLogicalSize(renderer_, w, h);
+		SDL_RenderSetLogicalSize(renderer_, w / scale_, h / scale_);
 
 		info << "Using renderer: " << rinfo_.name;
 	}
@@ -27,18 +29,18 @@ public:
 	Vec2 getSize() {
 		int w, h;
 		SDL_GetWindowSize(window_, &w, &h);
-		return Vec2(((float)w / scale_) / TILE_SIZE, ((float)h / scale_) / TILE_SIZE);
+		return Vec2(((float)w / (scale_ * zoom_)) / TILE_SIZE, ((float)h / (scale_ * zoom_)) / TILE_SIZE);
 	}
 
 	void onResize(int w, int h) {
-		SDL_RenderSetLogicalSize(renderer_, w, h);
+		SDL_RenderSetLogicalSize(renderer_, w / scale_, h / scale_);
 	}
 
 	SDL_Rect createDestRect(Vec2 pos, Vec2 pixsize) {
 		return SDL_Rect{
-			(int)((pos.x - cam_.x) * TILE_SIZE * scale_),
-			(int)((pos.y - cam_.y) * TILE_SIZE * scale_),
-			(int)(pixsize.x * scale_), (int)(pixsize.y * scale_),
+			(int)((pos.x - cam_.x) * TILE_SIZE * zoom_),
+			(int)((pos.y - cam_.y) * TILE_SIZE * zoom_),
+			(int)(pixsize.x * zoom_), (int)(pixsize.y * zoom_),
 		};
 	}
 
@@ -74,10 +76,11 @@ public:
 			warn << "RenderDrawRect failed: " << SDL_GetError();
 	}
 
-	float scale_ = 2;
 	Vec2 cam_;
+	float zoom_ = 1;
 	SDL_Window *window_;
 	SDL_Renderer *renderer_;
+	float scale_;
 	SDL_RendererInfo rinfo_;
 };
 

libswan/src/Game.cc

@@ -39,8 +39,8 @@ void Game::createWorld(const std::string &worldgen, std::vector<std::unique_ptr<
 TilePos Game::getMouseTile() {
 	auto mousePos = getMousePos();
 	return TilePos(
-		(int)floor(win_.cam_.x + mousePos.x / (Swan::TILE_SIZE * win_.scale_)),
-		(int)floor(win_.cam_.y + mousePos.y / (Swan::TILE_SIZE * win_.scale_)));
+		(int)floor(win_.cam_.x + mousePos.x / (Swan::TILE_SIZE * win_.zoom_)),
+		(int)floor(win_.cam_.y + mousePos.y / (Swan::TILE_SIZE * win_.zoom_)));
 }
 
 void Game::draw() {

src/main.cc

@@ -8,6 +8,8 @@
 #include <SDL2/SDL.h>
 #include <SDL2/SDL_image.h>
 #include <string.h>
+#include <imgui.h>
+#include <imgui_sdl/imgui_sdl.h>
 
 #include <swan/swan.h>
 
@@ -23,8 +25,24 @@ using namespace Swan;
 #define sdlassert(expr, str) errassert(expr, str, SDL_GetError);
 #define imgassert(expr, str) errassert(expr, str, IMG_GetError);
 
-template<typename T>
-using DeleteFunc = void (*)(T *);
+// ImGUI and SDL have different numbers for mouse buttons
+int sdlButtonToImGuiButton(uint8_t button) {
+	switch (button) {
+	case SDL_BUTTON_LEFT:
+		return 0;
+	case SDL_BUTTON_RIGHT:
+		return 1;
+	case SDL_BUTTON_MIDDLE:
+		return 2;
+	case SDL_BUTTON_X1:
+		return 3;
+	case SDL_BUTTON_X2:
+		return 4;
+	default:
+		warn << "Unknown mouse button: " << button;
+		return 4; // Let's call that X2?
+	}
+}
 
 int main(int argc, char **argv) {
 	uint32_t winflags = SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI;
@@ -54,6 +72,7 @@ int main(int argc, char **argv) {
 	imgassert(IMG_Init(imgflags) == imgflags, "Could not initialize SDL_Image");
 	auto sdl_image = makeDeferred([] { IMG_Quit(); });
 
+	// Create the window
 	auto window = makeRaiiPtr(
 		SDL_CreateWindow(
 			"Project: SWAN",
@@ -73,8 +92,20 @@ int main(int argc, char **argv) {
 		SDL_DestroyRenderer);
 	sdlassert(renderer, "Could not create renderer");
 
-	Win win(window.get(), renderer.get());
+	Win win(window.get(), renderer.get(), 2);
+
+	// Init ImGUI and ImGUI_SDL
+	IMGUI_CHECKVERSION();
+    ImGui::CreateContext();
+	auto imgui = makeDeferred([] { ImGui::DestroyContext(); });
+	ImGuiSDL::Initialize(renderer.get(), 640, 480);
+	auto imgui_sdl = makeDeferred([] { ImGuiSDL::Deinitialize(); });
 
+	// ImGuiIO is to glue SDL and ImGUI together
+	ImGuiIO& imgui_io = ImGui::GetIO();
+	imgui_io.BackendPlatformName = "imgui_sdl + Project: SWAN";
+
+	// Create a world
 	Game game(win);
 	std::vector<std::unique_ptr<Mod>> mods;
 	mods.push_back(game.loadMod("core.mod"));
@@ -100,8 +131,11 @@ int main(int argc, char **argv) {
 				break;
 
 			case SDL_WINDOWEVENT:
-				if (evt.window.event == SDL_WINDOWEVENT_RESIZED)
+				if (evt.window.event == SDL_WINDOWEVENT_RESIZED) {
+					imgui_io.DisplaySize.x = (float)evt.window.data1;
+					imgui_io.DisplaySize.y = (float)evt.window.data2;
 					win.onResize(evt.window.data1, evt.window.data2);
+				}
 				break;
 
 			case SDL_KEYDOWN:
@@ -113,14 +147,18 @@ int main(int argc, char **argv) {
 				break;
 
 			case SDL_MOUSEMOTION:
+				imgui_io.MousePos.x = (float)evt.motion.x;
+				imgui_io.MousePos.y = (float)evt.motion.y;
 				game.onMouseMove(evt.motion.x, evt.motion.y);
 				break;
 
 			case SDL_MOUSEBUTTONDOWN:
+				imgui_io.MouseDown[sdlButtonToImGuiButton(evt.button.button)] = true;
 				game.onMouseDown(evt.button.x, evt.button.y, evt.button.button);
 				break;
 
 			case SDL_MOUSEBUTTONUP:
+				imgui_io.MouseDown[sdlButtonToImGuiButton(evt.button.button)] = false;
 				game.onMouseUp(evt.button.x, evt.button.y, evt.button.button);
 				break;
 			}
@@ -184,12 +222,21 @@ int main(int argc, char **argv) {
 
 		SDL_RenderClear(renderer.get());
 
+		// ImGUI
+		imgui_io.DeltaTime = dt;
+		ImGui::NewFrame();
+		ImGui::ShowDemoWindow();
+
 		RTClock draw_clock;
 		game.draw();
 		pcounter.countGameDraw(draw_clock.duration());
 
 		pcounter.countFrameTime(total_frame_clock.duration());
 
+		// Render ImGUI
+		ImGui::Render();
+		ImGuiSDL::Render(ImGui::GetDrawData());
+
 		RTClock present_clock;
 		SDL_RenderPresent(renderer.get());
 		pcounter.countRenderPresent(present_clock.duration());

third_party/CMakeLists.txt

@@ -2,7 +2,12 @@ add_library(imgui SHARED
 	${PROJECT_SOURCE_DIR}/third_party/imgui/imgui_demo.cpp
 	${PROJECT_SOURCE_DIR}/third_party/imgui/imgui_draw.cpp
 	${PROJECT_SOURCE_DIR}/third_party/imgui/imgui_widgets.cpp
-	${PROJECT_SOURCE_DIR}/third_party/imgui/imgui.cpp)
+	${PROJECT_SOURCE_DIR}/third_party/imgui/imgui.cpp
+	${PROJECT_SOURCE_DIR}/third_party/imgui_sdl/imgui_sdl.cpp)
 set_target_properties(imgui PROPERTIES CXX_CLANG_TIDY "")
+target_include_directories(imgui PUBLIC
+	${PROJECT_SOURCE_DIR}/third_party/imgui
+	${PROJECT_SOURCE_DIR}/third_party/imgui/examples
+	${SDL2_INCLUDE_DIRS})
 
 install(TARGETS imgui DESTINATION swan/third_party)

third_party/imgui_sdl

@@ -0,0 +1 @@
+Subproject commit b9ba533ba28bd875c75b04888bdde2ab4e464122