examples/example_sdl2_sdlrenderer2/main.cpp - third_party/imgui - Git at Google

 // Dear ImGui: standalone example application for SDL2 + SDL_Renderer
 // (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)

 // Learn about Dear ImGui:
 // - FAQ                  https://dearimgui.com/faq
 // - Getting Started      https://dearimgui.com/getting-started
 // - Documentation        https://dearimgui.com/docs (same as your local docs/ folder).
 // - Introduction, links and more at the top of imgui.cpp

 // Important to understand: SDL_Renderer is an _optional_ component of SDL2.
 // For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.

 #include "imgui.h"
 #include "imgui_impl_sdl2.h"
 #include "imgui_impl_sdlrenderer2.h"
 #include <stdio.h>
 #include <SDL.h>

 #if !SDL_VERSION_ATLEAST(2,0,17)
 #error This backend requires SDL 2.0.17+ because of SDL_RenderGeometry() function
 #endif

 // Main code
 int main(int, char**)
 {
     // Setup SDL
     if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
     {
         printf("Error: %s\n", SDL_GetError());
         return -1;
     }

     // From 2.0.18: Enable native IME.
 #ifdef SDL_HINT_IME_SHOW_UI
     SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
 #endif

     // Create window with SDL_Renderer graphics context
     SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
     SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+SDL_Renderer example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
     if (window == nullptr)
     {
         printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
         return -1;
     }
     SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
     if (renderer == nullptr)
     {
         SDL_Log("Error creating SDL_Renderer!");
         return -1;
     }
     //SDL_RendererInfo info;
     //SDL_GetRendererInfo(renderer, &info);
     //SDL_Log("Current SDL_Renderer: %s", info.name);

     // Setup Dear ImGui context
     IMGUI_CHECKVERSION();
     ImGui::CreateContext();
     ImGuiIO& io = ImGui::GetIO(); (void)io;
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard;     // Enable Keyboard Controls
     io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad;      // Enable Gamepad Controls

     // Setup Dear ImGui style
     ImGui::StyleColorsDark();
     //ImGui::StyleColorsLight();

     // Setup Platform/Renderer backends
     ImGui_ImplSDL2_InitForSDLRenderer(window, renderer);
     ImGui_ImplSDLRenderer2_Init(renderer);

     // Load Fonts
     // - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
     // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
     // - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
     // - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
     // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
     // - Read 'docs/FONTS.md' for more instructions and details.
     // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
     //io.Fonts->AddFontDefault();
     //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
     //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
     //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
     //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
     //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
     //IM_ASSERT(font != nullptr);

     // Our state
     bool show_demo_window = true;
     bool show_another_window = false;
     ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);

     // Main loop
     bool done = false;
     while (!done)
     {
         // Poll and handle events (inputs, window resize, etc.)
         // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
         // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
         // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
         // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
         SDL_Event event;
         while (SDL_PollEvent(&event))
         {
             ImGui_ImplSDL2_ProcessEvent(&event);
             if (event.type == SDL_QUIT)
                 done = true;
             if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
                 done = true;
         }
         if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
         {
             SDL_Delay(10);
             continue;
         }

         // Start the Dear ImGui frame
         ImGui_ImplSDLRenderer2_NewFrame();
         ImGui_ImplSDL2_NewFrame();
         ImGui::NewFrame();

         // 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
         if (show_demo_window)
             ImGui::ShowDemoWindow(&show_demo_window);

         // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
         {
             static float f = 0.0f;
             static int counter = 0;

             ImGui::Begin("Hello, world!");                          // Create a window called "Hello, world!" and append into it.

             ImGui::Text("This is some useful text.");               // Display some text (you can use a format strings too)
             ImGui::Checkbox("Demo Window", &show_demo_window);      // Edit bools storing our window open/close state
             ImGui::Checkbox("Another Window", &show_another_window);

             ImGui::SliderFloat("float", &f, 0.0f, 1.0f);            // Edit 1 float using a slider from 0.0f to 1.0f
             ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color

             if (ImGui::Button("Button"))                            // Buttons return true when clicked (most widgets return true when edited/activated)
                 counter++;
             ImGui::SameLine();
             ImGui::Text("counter = %d", counter);

             ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
             ImGui::End();
         }

         // 3. Show another simple window.
         if (show_another_window)
         {
             ImGui::Begin("Another Window", &show_another_window);   // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
             ImGui::Text("Hello from another window!");
             if (ImGui::Button("Close Me"))
                 show_another_window = false;
             ImGui::End();
         }

         // Rendering
         ImGui::Render();
         SDL_RenderSetScale(renderer, io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y);
         SDL_SetRenderDrawColor(renderer, (Uint8)(clear_color.x * 255), (Uint8)(clear_color.y * 255), (Uint8)(clear_color.z * 255), (Uint8)(clear_color.w * 255));
         SDL_RenderClear(renderer);
         ImGui_ImplSDLRenderer2_RenderDrawData(ImGui::GetDrawData(), renderer);
         SDL_RenderPresent(renderer);
     }

     // Cleanup
     ImGui_ImplSDLRenderer2_Shutdown();
     ImGui_ImplSDL2_Shutdown();
     ImGui::DestroyContext();

     SDL_DestroyRenderer(renderer);
     SDL_DestroyWindow(window);
     SDL_Quit();

     return 0;
 }
	// Dear ImGui: standalone example application for SDL2 + SDL_Renderer
	// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)

	// Learn about Dear ImGui:
	// - FAQ https://dearimgui.com/faq
	// - Getting Started https://dearimgui.com/getting-started
	// - Documentation https://dearimgui.com/docs (same as your local docs/ folder).
	// - Introduction, links and more at the top of imgui.cpp

	// Important to understand: SDL_Renderer is an _optional_ component of SDL2.
	// For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.

	#include "imgui.h"
	#include "imgui_impl_sdl2.h"
	#include "imgui_impl_sdlrenderer2.h"
	#include <stdio.h>
	#include <SDL.h>

	#if !SDL_VERSION_ATLEAST(2,0,17)
	#error This backend requires SDL 2.0.17+ because of SDL_RenderGeometry() function
	#endif

	// Main code
	int main(int, char**)
	{
	// Setup SDL
	if (SDL_Init(SDL_INIT_VIDEO \| SDL_INIT_TIMER \| SDL_INIT_GAMECONTROLLER) != 0)
	{
	printf("Error: %s\n", SDL_GetError());
	return -1;
	}

	// From 2.0.18: Enable native IME.
	#ifdef SDL_HINT_IME_SHOW_UI
	SDL_SetHint(SDL_HINT_IME_SHOW_UI, "1");
	#endif

	// Create window with SDL_Renderer graphics context
	SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_RESIZABLE \| SDL_WINDOW_ALLOW_HIGHDPI);
	SDL_Window* window = SDL_CreateWindow("Dear ImGui SDL2+SDL_Renderer example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, 1280, 720, window_flags);
	if (window == nullptr)
	{
	printf("Error: SDL_CreateWindow(): %s\n", SDL_GetError());
	return -1;
	}
	SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC \| SDL_RENDERER_ACCELERATED);
	if (renderer == nullptr)
	{
	SDL_Log("Error creating SDL_Renderer!");
	return -1;
	}
	//SDL_RendererInfo info;
	//SDL_GetRendererInfo(renderer, &info);
	//SDL_Log("Current SDL_Renderer: %s", info.name);

	// Setup Dear ImGui context
	IMGUI_CHECKVERSION();
	ImGui::CreateContext();
	ImGuiIO& io = ImGui::GetIO(); (void)io;
	io.ConfigFlags \|= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls
	io.ConfigFlags \|= ImGuiConfigFlags_NavEnableGamepad; // Enable Gamepad Controls

	// Setup Dear ImGui style
	ImGui::StyleColorsDark();
	//ImGui::StyleColorsLight();

	// Setup Platform/Renderer backends
	ImGui_ImplSDL2_InitForSDLRenderer(window, renderer);
	ImGui_ImplSDLRenderer2_Init(renderer);

	// Load Fonts
	// - If no fonts are loaded, dear imgui will use the default font. You can also load multiple fonts and use ImGui::PushFont()/PopFont() to select them.
	// - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
	// - If the file cannot be loaded, the function will return a nullptr. Please handle those errors in your application (e.g. use an assertion, or display an error and quit).
	// - The fonts will be rasterized at a given size (w/ oversampling) and stored into a texture when calling ImFontAtlas::Build()/GetTexDataAsXXXX(), which ImGui_ImplXXXX_NewFrame below will call.
	// - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
	// - Read 'docs/FONTS.md' for more instructions and details.
	// - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
	//io.Fonts->AddFontDefault();
	//io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
	//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
	//ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
	//IM_ASSERT(font != nullptr);

	// Our state
	bool show_demo_window = true;
	bool show_another_window = false;
	ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);

	// Main loop
	bool done = false;
	while (!done)
	{
	// Poll and handle events (inputs, window resize, etc.)
	// You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
	// - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
	// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
	// Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
	SDL_Event event;
	while (SDL_PollEvent(&event))
	{
	ImGui_ImplSDL2_ProcessEvent(&event);
	if (event.type == SDL_QUIT)
	done = true;
	if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
	done = true;
	}
	if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
	{
	SDL_Delay(10);
	continue;
	}

	// Start the Dear ImGui frame
	ImGui_ImplSDLRenderer2_NewFrame();
	ImGui_ImplSDL2_NewFrame();
	ImGui::NewFrame();

	// 1. Show the big demo window (Most of the sample code is in ImGui::ShowDemoWindow()! You can browse its code to learn more about Dear ImGui!).
	if (show_demo_window)
	ImGui::ShowDemoWindow(&show_demo_window);

	// 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
	{
	static float f = 0.0f;
	static int counter = 0;

	ImGui::Begin("Hello, world!"); // Create a window called "Hello, world!" and append into it.

	ImGui::Text("This is some useful text."); // Display some text (you can use a format strings too)
	ImGui::Checkbox("Demo Window", &show_demo_window); // Edit bools storing our window open/close state
	ImGui::Checkbox("Another Window", &show_another_window);

	ImGui::SliderFloat("float", &f, 0.0f, 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f
	ImGui::ColorEdit3("clear color", (float*)&clear_color); // Edit 3 floats representing a color

	if (ImGui::Button("Button")) // Buttons return true when clicked (most widgets return true when edited/activated)
	counter++;
	ImGui::SameLine();
	ImGui::Text("counter = %d", counter);

	ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
	ImGui::End();
	}

	// 3. Show another simple window.
	if (show_another_window)
	{
	ImGui::Begin("Another Window", &show_another_window); // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
	ImGui::Text("Hello from another window!");
	if (ImGui::Button("Close Me"))
	show_another_window = false;
	ImGui::End();
	}

	// Rendering
	ImGui::Render();
	SDL_RenderSetScale(renderer, io.DisplayFramebufferScale.x, io.DisplayFramebufferScale.y);
	SDL_SetRenderDrawColor(renderer, (Uint8)(clear_color.x * 255), (Uint8)(clear_color.y * 255), (Uint8)(clear_color.z * 255), (Uint8)(clear_color.w * 255));
	SDL_RenderClear(renderer);
	ImGui_ImplSDLRenderer2_RenderDrawData(ImGui::GetDrawData(), renderer);
	SDL_RenderPresent(renderer);
	}

	// Cleanup
	ImGui_ImplSDLRenderer2_Shutdown();
	ImGui_ImplSDL2_Shutdown();
	ImGui::DestroyContext();

	SDL_DestroyRenderer(renderer);
	SDL_DestroyWindow(window);
	SDL_Quit();

	return 0;
	}