#ifdef _MSC_VER #pragma warning (disable: 4996) // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen #include <Windows.h> #include <Imm.h> #endif #define STB_IMAGE_IMPLEMENTATION #include "stb_image.h" // for .png loading #include "../../imgui.h" // glew & glfw #define GLEW_STATIC #include <GL/glew.h> #include <GLFW/glfw3.h> #ifdef _MSC_VER #define GLFW_EXPOSE_NATIVE_WIN32 #define GLFW_EXPOSE_NATIVE_WGL #include <GLFW/glfw3native.h> #endif static GLFWwindow* window; static GLuint fontTex; static bool mousePressed[2] = { false, false }; static ImVec2 mousePosScale(1.0f, 1.0f); // This is the main rendering function that you have to implement and provide to ImGui (via setting up 'RenderDrawListsFn' in the ImGuiIO structure) // If text or lines are blurry when integrating ImGui in your engine: // - in your Render function, try translating your projection matrix by (0.5f,0.5f) or (0.375f,0.375f) // - try adjusting ImGui::GetIO().PixelCenterOffset to 0.5f or 0.375f static void ImImpl_RenderDrawLists(ImDrawList** const cmd_lists, int cmd_lists_count) { if (cmd_lists_count == 0) return; // We are using the OpenGL fixed pipeline to make the example code simpler to read! // A probable faster way to render would be to collate all vertices from all cmd_lists into a single vertex buffer. // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers. glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT); glEnable(GL_BLEND); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glDisable(GL_CULL_FACE); glDisable(GL_DEPTH_TEST); glEnable(GL_SCISSOR_TEST); glEnableClientState(GL_VERTEX_ARRAY); glEnableClientState(GL_TEXTURE_COORD_ARRAY); glEnableClientState(GL_COLOR_ARRAY); // Setup texture glBindTexture(GL_TEXTURE_2D, fontTex); glEnable(GL_TEXTURE_2D); // Setup orthographic projection matrix const float width = ImGui::GetIO().DisplaySize.x; const float height = ImGui::GetIO().DisplaySize.y; glMatrixMode(GL_PROJECTION); glPushMatrix(); glLoadIdentity(); glOrtho(0.0f, width, height, 0.0f, -1.0f, +1.0f); glMatrixMode(GL_MODELVIEW); glPushMatrix(); glLoadIdentity(); // Render command lists for (int n = 0; n < cmd_lists_count; n++) { const ImDrawList* cmd_list = cmd_lists[n]; const unsigned char* vtx_buffer = (const unsigned char*)&cmd_list->vtx_buffer.front(); glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + offsetof(ImDrawVert, pos))); glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + offsetof(ImDrawVert, uv))); glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (void*)(vtx_buffer + offsetof(ImDrawVert, col))); int vtx_offset = 0; for (size_t cmd_i = 0; cmd_i < cmd_list->commands.size(); cmd_i++) { const ImDrawCmd* pcmd = &cmd_list->commands[cmd_i]; glScissor((int)pcmd->clip_rect.x, (int)(height - pcmd->clip_rect.w), (int)(pcmd->clip_rect.z - pcmd->clip_rect.x), (int)(pcmd->clip_rect.w - pcmd->clip_rect.y)); glDrawArrays(GL_TRIANGLES, vtx_offset, pcmd->vtx_count); vtx_offset += pcmd->vtx_count; } } glDisableClientState(GL_COLOR_ARRAY); glDisableClientState(GL_TEXTURE_COORD_ARRAY); glDisableClientState(GL_VERTEX_ARRAY); // Restore modified state glMatrixMode(GL_MODELVIEW); glPopMatrix(); glMatrixMode(GL_PROJECTION); glPopMatrix(); glPopAttrib(); } // NB: ImGui already provide OS clipboard support for Windows so this isn't needed if you are using Windows only. static const char* ImImpl_GetClipboardTextFn() { return glfwGetClipboardString(window); } static void ImImpl_SetClipboardTextFn(const char* text) { glfwSetClipboardString(window, text); } #ifdef _MSC_VER // Notify OS Input Method Editor of text input position (e.g. when using Japanese/Chinese inputs, otherwise this isn't needed) static void ImImpl_ImeSetInputScreenPosFn(int x, int y) { HWND hwnd = glfwGetWin32Window(window); if (HIMC himc = ImmGetContext(hwnd)) { COMPOSITIONFORM cf; cf.ptCurrentPos.x = x; cf.ptCurrentPos.y = y; cf.dwStyle = CFS_FORCE_POSITION; ImmSetCompositionWindow(himc, &cf); } } #endif // GLFW callbacks to get events static void glfw_error_callback(int error, const char* description) { fputs(description, stderr); } static void glfw_mouse_button_callback(GLFWwindow* window, int button, int action, int mods) { if (action == GLFW_PRESS && button >= 0 && button < 2) mousePressed[button] = true; } static void glfw_scroll_callback(GLFWwindow* window, double xoffset, double yoffset) { ImGuiIO& io = ImGui::GetIO(); io.MouseWheel = (float)yoffset; // Use fractional mouse wheel, 1.0 unit 5 lines. } static void glfw_key_callback(GLFWwindow* window, int key, int scancode, int action, int mods) { ImGuiIO& io = ImGui::GetIO(); if (action == GLFW_PRESS) io.KeysDown[key] = true; if (action == GLFW_RELEASE) io.KeysDown[key] = false; io.KeyCtrl = (mods & GLFW_MOD_CONTROL) != 0; io.KeyShift = (mods & GLFW_MOD_SHIFT) != 0; } static void glfw_char_callback(GLFWwindow* window, unsigned int c) { if (c > 0 && c < 0x10000) ImGui::GetIO().AddInputCharacter((unsigned short)c); } // OpenGL code based on http://open.gl tutorials void InitGL() { glfwSetErrorCallback(glfw_error_callback); if (!glfwInit()) exit(1); glfwWindowHint(GLFW_RESIZABLE, GL_FALSE); window = glfwCreateWindow(1280, 720, "ImGui OpenGL example", NULL, NULL); glfwMakeContextCurrent(window); glfwSetKeyCallback(window, glfw_key_callback); glfwSetMouseButtonCallback(window, glfw_mouse_button_callback); glfwSetScrollCallback(window, glfw_scroll_callback); glfwSetCharCallback(window, glfw_char_callback); glewInit(); } void InitImGui() { int w, h; int fb_w, fb_h; glfwGetWindowSize(window, &w, &h); glfwGetFramebufferSize(window, &fb_w, &fb_h); mousePosScale.x = (float)fb_w / w; // Some screens e.g. Retina display have framebuffer size != from window size, and mouse inputs are given in window/screen coordinates. mousePosScale.y = (float)fb_h / h; ImGuiIO& io = ImGui::GetIO(); io.DisplaySize = ImVec2((float)fb_w, (float)fb_h); // Display size, in pixels. For clamping windows positions. io.DeltaTime = 1.0f/60.0f; // Time elapsed since last frame, in seconds (in this sample app we'll override this every frame because our timestep is variable) io.PixelCenterOffset = 0.0f; // Align OpenGL texels io.KeyMap[ImGuiKey_Tab] = GLFW_KEY_TAB; // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array. io.KeyMap[ImGuiKey_LeftArrow] = GLFW_KEY_LEFT; io.KeyMap[ImGuiKey_RightArrow] = GLFW_KEY_RIGHT; io.KeyMap[ImGuiKey_UpArrow] = GLFW_KEY_UP; io.KeyMap[ImGuiKey_DownArrow] = GLFW_KEY_DOWN; io.KeyMap[ImGuiKey_Home] = GLFW_KEY_HOME; io.KeyMap[ImGuiKey_End] = GLFW_KEY_END; io.KeyMap[ImGuiKey_Delete] = GLFW_KEY_DELETE; io.KeyMap[ImGuiKey_Backspace] = GLFW_KEY_BACKSPACE; io.KeyMap[ImGuiKey_Enter] = GLFW_KEY_ENTER; io.KeyMap[ImGuiKey_Escape] = GLFW_KEY_ESCAPE; io.KeyMap[ImGuiKey_A] = GLFW_KEY_A; io.KeyMap[ImGuiKey_C] = GLFW_KEY_C; io.KeyMap[ImGuiKey_V] = GLFW_KEY_V; io.KeyMap[ImGuiKey_X] = GLFW_KEY_X; io.KeyMap[ImGuiKey_Y] = GLFW_KEY_Y; io.KeyMap[ImGuiKey_Z] = GLFW_KEY_Z; io.RenderDrawListsFn = ImImpl_RenderDrawLists; io.SetClipboardTextFn = ImImpl_SetClipboardTextFn; io.GetClipboardTextFn = ImImpl_GetClipboardTextFn; #ifdef _MSC_VER io.ImeSetInputScreenPosFn = ImImpl_ImeSetInputScreenPosFn; #endif // Load font texture glGenTextures(1, &fontTex); glBindTexture(GL_TEXTURE_2D, fontTex); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_NEAREST); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_NEAREST); #if 1 // Default font (embedded in code) const void* png_data; unsigned int png_size; ImGui::GetDefaultFontData(NULL, NULL, &png_data, &png_size); int tex_x, tex_y, tex_comp; void* tex_data = stbi_load_from_memory((const unsigned char*)png_data, (int)png_size, &tex_x, &tex_y, &tex_comp, 0); IM_ASSERT(tex_data != NULL); #else // Custom font from filesystem io.Font = new ImFont(); io.Font->LoadFromFile("../../extra_fonts/mplus-2m-medium_18.fnt"); IM_ASSERT(io.Font->IsLoaded()); int tex_x, tex_y, tex_comp; void* tex_data = stbi_load("../../extra_fonts/mplus-2m-medium_18.png", &tex_x, &tex_y, &tex_comp, 0); IM_ASSERT(tex_data != NULL); // Automatically find white pixel from the texture we just loaded // (io.Font->TexUvForWhite needs to contains UV coordinates pointing to a white pixel in order to render solid objects) for (int tex_data_off = 0; tex_data_off < tex_x*tex_y; tex_data_off++) if (((unsigned int*)tex_data)[tex_data_off] == 0xffffffff) { io.Font->TexUvForWhite = ImVec2((float)(tex_data_off % tex_x)/(tex_x), (float)(tex_data_off / tex_x)/(tex_y)); break; } #endif glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, tex_x, tex_y, 0, GL_RGBA, GL_UNSIGNED_BYTE, tex_data); stbi_image_free(tex_data); } void UpdateImGui() { ImGuiIO& io = ImGui::GetIO(); // Setup timestep static double time = 0.0f; const double current_time = glfwGetTime(); io.DeltaTime = (float)(current_time - time); time = current_time; // Setup inputs // (we already got mouse wheel, keyboard keys & characters from glfw callbacks polled in glfwPollEvents()) double mouse_x, mouse_y; glfwGetCursorPos(window, &mouse_x, &mouse_y); io.MousePos = ImVec2((float)mouse_x * mousePosScale.x, (float)mouse_y * mousePosScale.y); // Mouse position, in pixels (set to -1,-1 if no mouse / on another screen, etc.) io.MouseDown[0] = mousePressed[0] || glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_LEFT) != 0; // If a mouse press event came, always pass it as "mouse held this frame", so we don't miss click-release events that are shorter than 1 frame. io.MouseDown[1] = mousePressed[1] || glfwGetMouseButton(window, GLFW_MOUSE_BUTTON_RIGHT) != 0; // Start the frame ImGui::NewFrame(); } // Application code int main(int argc, char** argv) { InitGL(); InitImGui(); while (!glfwWindowShouldClose(window)) { ImGuiIO& io = ImGui::GetIO(); mousePressed[0] = mousePressed[1] = false; io.MouseWheel = 0; glfwPollEvents(); UpdateImGui(); static bool show_test_window = true; static bool show_another_window = false; // 1. Show a simple window // Tip: if we don't call ImGui::Begin()/ImGui::End() the widgets appears in a window automatically called "Debug" { static float f; ImGui::Text("Hello, world!"); ImGui::SliderFloat("float", &f, 0.0f, 1.0f); show_test_window ^= ImGui::Button("Test Window"); show_another_window ^= ImGui::Button("Another Window"); // Calculate and show framerate static float ms_per_frame[120] = { 0 }; static int ms_per_frame_idx = 0; static float ms_per_frame_accum = 0.0f; ms_per_frame_accum -= ms_per_frame[ms_per_frame_idx]; ms_per_frame[ms_per_frame_idx] = ImGui::GetIO().DeltaTime * 1000.0f; ms_per_frame_accum += ms_per_frame[ms_per_frame_idx]; ms_per_frame_idx = (ms_per_frame_idx + 1) % 120; const float ms_per_frame_avg = ms_per_frame_accum / 120; ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", ms_per_frame_avg, 1000.0f / ms_per_frame_avg); } // 2. Show another simple window, this time using an explicit Begin/End pair if (show_another_window) { ImGui::Begin("Another Window", &show_another_window, ImVec2(200,100)); ImGui::Text("Hello"); ImGui::End(); } // 3. Show the ImGui test window. Most of the sample code is in ImGui::ShowTestWindow() if (show_test_window) { ImGui::SetNewWindowDefaultPos(ImVec2(650, 20)); // Normally user code doesn't need/want to call this, because positions are saved in .ini file. Here we just want to make the demo initial state a bit more friendly! ImGui::ShowTestWindow(&show_test_window); } // Rendering glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y); glClearColor(0.8f, 0.6f, 0.6f, 1.0f); glClear(GL_COLOR_BUFFER_BIT); ImGui::Render(); glfwSwapBuffers(window); } ImGui::Shutdown(); glfwTerminate(); return 0; }