1// Dear ImGui: standalone example application for SDL2 + SDL_Renderer
2// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan/Metal graphics context creation, etc.)
3
4// Learn about Dear ImGui:
5// - FAQ https://dearimgui.com/faq
6// - Getting Started https://dearimgui.com/getting-started
7// - Documentation https://dearimgui.com/docs (same as your local docs/ folder).
8// - Introduction, links and more at the top of imgui.cpp
9
10// Important to understand: SDL_Renderer is an _optional_ component of SDL2.
11// For a multi-platform app consider using e.g. SDL+DirectX on Windows and SDL+OpenGL on Linux/OSX.
12
13#include "imgui.h"
14#include "imgui_impl_sdl2.h"
15#include "imgui_impl_sdlrenderer2.h"
16#include <stdio.h>
17#include <SDL.h>
18
19#if !SDL_VERSION_ATLEAST(2,0,17)
20#error This backend requires SDL 2.0.17+ because of SDL_RenderGeometry() function
21#endif
22
23// Main code
24int main(int, char**)
25{
26 // Setup SDL
27 if (SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER | SDL_INIT_GAMECONTROLLER) != 0)
28 {
29 printf(format: "Error: %s\n", SDL_GetError());
30 return -1;
31 }
32
33 // From 2.0.18: Enable native IME.
34#ifdef SDL_HINT_IME_SHOW_UI
35 SDL_SetHint(SDL_HINT_IME_SHOW_UI, value: "1");
36#endif
37
38 // Create window with SDL_Renderer graphics context
39 SDL_WindowFlags window_flags = (SDL_WindowFlags)(SDL_WINDOW_RESIZABLE | SDL_WINDOW_ALLOW_HIGHDPI);
40 SDL_Window* window = SDL_CreateWindow(title: "Dear ImGui SDL2+SDL_Renderer example", SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED, w: 1280, h: 720, flags: window_flags);
41 if (window == nullptr)
42 {
43 printf(format: "Error: SDL_CreateWindow(): %s\n", SDL_GetError());
44 return -1;
45 }
46 SDL_Renderer* renderer = SDL_CreateRenderer(window, index: -1, flags: SDL_RENDERER_PRESENTVSYNC | SDL_RENDERER_ACCELERATED);
47 if (renderer == nullptr)
48 {
49 SDL_Log(fmt: "Error creating SDL_Renderer!");
50 return -1;
51 }
52 //SDL_RendererInfo info;
53 //SDL_GetRendererInfo(renderer, &info);
54 //SDL_Log("Current SDL_Renderer: %s", info.name);
55
56 // Setup Dear ImGui context
57 IMGUI_CHECKVERSION();
58 ImGui::CreateContext();
59 ImGuiIO& io = ImGui::GetIO(); (void)io;
60 io.ConfigFlags |= ImGuiConfigFlags_NavEnableKeyboard; // Enable Keyboard Controls
61 io.ConfigFlags |= ImGuiConfigFlags_NavEnableGamepad; // Enable Gamepad Controls
62 io.ConfigFlags |= ImGuiConfigFlags_DockingEnable; // Enable Docking
63
64 // Setup Dear ImGui style
65 ImGui::StyleColorsDark();
66 //ImGui::StyleColorsLight();
67
68 // Setup Platform/Renderer backends
69 ImGui_ImplSDL2_InitForSDLRenderer(window, renderer);
70 ImGui_ImplSDLRenderer2_Init(renderer);
71
72 // Load Fonts
73 // - 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.
74 // - AddFontFromFileTTF() will return the ImFont* so you can store it if you need to select the font among multiple.
75 // - 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).
76 // - 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.
77 // - Use '#define IMGUI_ENABLE_FREETYPE' in your imconfig file to use Freetype for higher quality font rendering.
78 // - Read 'docs/FONTS.md' for more instructions and details.
79 // - Remember that in C/C++ if you want to include a backslash \ in a string literal you need to write a double backslash \\ !
80 //io.Fonts->AddFontDefault();
81 //io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\segoeui.ttf", 18.0f);
82 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/DroidSans.ttf", 16.0f);
83 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Roboto-Medium.ttf", 16.0f);
84 //io.Fonts->AddFontFromFileTTF("../../misc/fonts/Cousine-Regular.ttf", 15.0f);
85 //ImFont* font = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 18.0f, nullptr, io.Fonts->GetGlyphRangesJapanese());
86 //IM_ASSERT(font != nullptr);
87
88 // Our state
89 bool show_demo_window = true;
90 bool show_another_window = false;
91 ImVec4 clear_color = ImVec4(0.45f, 0.55f, 0.60f, 1.00f);
92
93 // Main loop
94 bool done = false;
95 while (!done)
96 {
97 // Poll and handle events (inputs, window resize, etc.)
98 // You can read the io.WantCaptureMouse, io.WantCaptureKeyboard flags to tell if dear imgui wants to use your inputs.
99 // - When io.WantCaptureMouse is true, do not dispatch mouse input data to your main application, or clear/overwrite your copy of the mouse data.
100 // - When io.WantCaptureKeyboard is true, do not dispatch keyboard input data to your main application, or clear/overwrite your copy of the keyboard data.
101 // Generally you may always pass all inputs to dear imgui, and hide them from your application based on those two flags.
102 SDL_Event event;
103 while (SDL_PollEvent(event: &event))
104 {
105 ImGui_ImplSDL2_ProcessEvent(event: &event);
106 if (event.type == SDL_QUIT)
107 done = true;
108 if (event.type == SDL_WINDOWEVENT && event.window.event == SDL_WINDOWEVENT_CLOSE && event.window.windowID == SDL_GetWindowID(window))
109 done = true;
110 }
111 if (SDL_GetWindowFlags(window) & SDL_WINDOW_MINIMIZED)
112 {
113 SDL_Delay(ms: 10);
114 continue;
115 }
116
117 // Start the Dear ImGui frame
118 ImGui_ImplSDLRenderer2_NewFrame();
119 ImGui_ImplSDL2_NewFrame();
120 ImGui::NewFrame();
121
122 // 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!).
123 if (show_demo_window)
124 ImGui::ShowDemoWindow(p_open: &show_demo_window);
125
126 // 2. Show a simple window that we create ourselves. We use a Begin/End pair to create a named window.
127 {
128 static float f = 0.0f;
129 static int counter = 0;
130
131 ImGui::Begin(name: "Hello, world!"); // Create a window called "Hello, world!" and append into it.
132
133 ImGui::Text(fmt: "This is some useful text."); // Display some text (you can use a format strings too)
134 ImGui::Checkbox(label: "Demo Window", v: &show_demo_window); // Edit bools storing our window open/close state
135 ImGui::Checkbox(label: "Another Window", v: &show_another_window);
136
137 ImGui::SliderFloat(label: "float", v: &f, v_min: 0.0f, v_max: 1.0f); // Edit 1 float using a slider from 0.0f to 1.0f
138 ImGui::ColorEdit3(label: "clear color", col: (float*)&clear_color); // Edit 3 floats representing a color
139
140 if (ImGui::Button(label: "Button")) // Buttons return true when clicked (most widgets return true when edited/activated)
141 counter++;
142 ImGui::SameLine();
143 ImGui::Text(fmt: "counter = %d", counter);
144
145 ImGui::Text(fmt: "Application average %.3f ms/frame (%.1f FPS)", 1000.0f / io.Framerate, io.Framerate);
146 ImGui::End();
147 }
148
149 // 3. Show another simple window.
150 if (show_another_window)
151 {
152 ImGui::Begin(name: "Another Window", p_open: &show_another_window); // Pass a pointer to our bool variable (the window will have a closing button that will clear the bool when clicked)
153 ImGui::Text(fmt: "Hello from another window!");
154 if (ImGui::Button(label: "Close Me"))
155 show_another_window = false;
156 ImGui::End();
157 }
158
159 // Rendering
160 ImGui::Render();
161 SDL_RenderSetScale(renderer, scaleX: io.DisplayFramebufferScale.x, scaleY: io.DisplayFramebufferScale.y);
162 SDL_SetRenderDrawColor(renderer, r: (Uint8)(clear_color.x * 255), g: (Uint8)(clear_color.y * 255), b: (Uint8)(clear_color.z * 255), a: (Uint8)(clear_color.w * 255));
163 SDL_RenderClear(renderer);
164 ImGui_ImplSDLRenderer2_RenderDrawData(draw_data: ImGui::GetDrawData(), renderer);
165 SDL_RenderPresent(renderer);
166 }
167
168 // Cleanup
169 ImGui_ImplSDLRenderer2_Shutdown();
170 ImGui_ImplSDL2_Shutdown();
171 ImGui::DestroyContext();
172
173 SDL_DestroyRenderer(renderer);
174 SDL_DestroyWindow(window);
175 SDL_Quit();
176
177 return 0;
178}
179

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source code of imgui/examples/example_sdl2_sdlrenderer2/main.cpp