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imgui/examples/example_sdl_sdlrenderer/main.cpp
Clownacy c6cab1f352 Backends: SDL: Added SDL_Renderer* parameter to ImGui_ImplSDL2_InitForSDLRenderer(). Use SDL_GetRendererOutputSize() instead of SDL_GL_GetDrawableSize() when bound to a SDL_Renderer. (#4927)
This is (kind of) an OpenGL-only function, which should be avoided when SDL2 isn't using OpenGL.
The only alternative that is recommended is SDL_GetRendererOutputSize, which limits this fix to the SDL_Renderer backend. Still, I think it's better than nothing.
I say that SDL_GL_GetDrawableSize is "kind of" OpenGL-only because it does technically work even when SDL2 isn't using OpenGL.
It's just that it becomes a shim to SDL_GetWindowSize, which is not suitable for high-DPI usage because it reflects the size of the window in screen coordinates, not actual pixels, so it really should be avoided when not using OpenGL.
2022-02-04 16:51:29 +01:00

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7.7 KiB
C++

// 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.)
// If you are new to Dear ImGui, read documentation from the docs/ folder + read the top of imgui.cpp.
// Read online: https://github.com/ocornut/imgui/tree/master/docs
// Important to understand: SDL_Renderer is an _optional_ component of SDL. We do not recommend you use SDL_Renderer
// because it provide a rather limited API to the end-user. We provide this backend for the sake of completeness.
// 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_sdl.h"
#include "imgui_impl_sdlrenderer.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
// (Some versions of SDL before <2.0.10 appears to have performance/stalling issues on a minority of Windows systems,
// depending on whether SDL_INIT_GAMECONTROLLER is enabled or disabled.. updating to latest version of SDL is recommended!)
if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
{
printf("Error: %s\n", SDL_GetError());
return -1;
}
// Setup window
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);
// Setup SDL_Renderer instance
SDL_Renderer* renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
if (renderer == NULL)
{
SDL_Log("Error creating SDL_Renderer!");
return false;
}
//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::StyleColorsClassic();
// Setup Platform/Renderer backends
ImGui_ImplSDL2_InitForSDLRenderer(window, renderer);
ImGui_ImplSDLRenderer_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 NULL. 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.
// - 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("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
//io.Fonts->AddFontFromFileTTF("../../misc/fonts/ProggyTiny.ttf", 10.0f);
//ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, NULL, io.Fonts->GetGlyphRangesJapanese());
//IM_ASSERT(font != NULL);
// 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.
// - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application.
// 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;
}
// Start the Dear ImGui frame
ImGui_ImplSDLRenderer_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 created 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 / ImGui::GetIO().Framerate, ImGui::GetIO().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_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_ImplSDLRenderer_RenderDrawData(ImGui::GetDrawData());
SDL_RenderPresent(renderer);
}
// Cleanup
ImGui_ImplSDLRenderer_Shutdown();
ImGui_ImplSDL2_Shutdown();
ImGui::DestroyContext();
SDL_DestroyRenderer(renderer);
SDL_DestroyWindow(window);
SDL_Quit();
return 0;
}