// ImGui - standalone example application for OpenGL 2, using fixed pipeline #ifdef _MSC_VER #pragma warning (disable: 4996) // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen #endif #ifdef __clang__ #pragma clang diagnostic ignored "-Wunused-function" // warning: unused function #endif #include "../../imgui.h" #include <stdio.h> // Glfw/Glew #define GLEW_STATIC #include <GL/glew.h> #include <GLFW/glfw3.h> #define OFFSETOF(TYPE, ELEMENT) ((size_t)&(((TYPE *)0)->ELEMENT)) static GLFWwindow* window; static bool mousePressed[2] = { false, false }; // 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) 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); 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]; glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->texture_id); 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; } } // Restore modified state glDisableClientState(GL_COLOR_ARRAY); glDisableClientState(GL_TEXTURE_COORD_ARRAY); glDisableClientState(GL_VERTEX_ARRAY); 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); } // 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); } void InitGL() { glfwSetErrorCallback(glfw_error_callback); if (!glfwInit()) exit(1); window = glfwCreateWindow(1280, 720, "ImGui OpenGL2 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 LoadFontsTexture() { ImGuiIO& io = ImGui::GetIO(); //ImFont* my_font1 = io.Fonts->AddFontDefault(); //ImFont* my_font2 = io.Fonts->AddFontFromFileTTF("extra_fonts/Karla-Regular.ttf", 15.0f); //ImFont* my_font3 = io.Fonts->AddFontFromFileTTF("extra_fonts/ProggyClean.ttf", 13.0f); my_font3->DisplayOffset.y += 1; //ImFont* my_font4 = io.Fonts->AddFontFromFileTTF("extra_fonts/ProggyTiny.ttf", 10.0f); my_font4->DisplayOffset.y += 1; //ImFont* my_font5 = io.Fonts->AddFontFromFileTTF("c:\\Windows\\Fonts\\ArialUni.ttf", 20.0f, io.Fonts->GetGlyphRangesJapanese()); unsigned char* pixels; int width, height; io.Fonts->GetTexDataAsAlpha8(&pixels, &width, &height); GLuint tex_id; glGenTextures(1, &tex_id); glBindTexture(GL_TEXTURE_2D, tex_id); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, pixels); // Store our identifier io.Fonts->TexID = (void *)(intptr_t)tex_id; } void InitImGui() { ImGuiIO& io = ImGui::GetIO(); 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 time step is variable) 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; LoadFontsTexture(); } void UpdateImGui() { ImGuiIO& io = ImGui::GetIO(); // Setup resolution (every frame to accommodate for window resizing) int w, h; int display_w, display_h; glfwGetWindowSize(window, &w, &h); glfwGetFramebufferSize(window, &display_w, &display_h); io.DisplaySize = ImVec2((float)display_w, (float)display_h); // Display size, in pixels. For clamping windows positions. // Setup time step 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); mouse_x *= (float)display_w / w; // Convert mouse coordinates to pixels mouse_y *= (float)display_h / h; io.MousePos = ImVec2((float)mouse_x, (float)mouse_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(); bool show_test_window = true; bool show_another_window = false; ImVec4 clear_col = ImColor(114, 144, 154); while (!glfwWindowShouldClose(window)) { ImGuiIO& io = ImGui::GetIO(); mousePressed[0] = mousePressed[1] = false; glfwPollEvents(); UpdateImGui(); // 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); ImGui::ColorEdit3("clear color", (float*)&clear_col); if (ImGui::Button("Test Window")) show_test_window ^= 1; if (ImGui::Button("Another Window")) show_another_window ^= 1; ImGui::Text("Application average %.3f ms/frame (%.1f FPS)", 1000.0f / ImGui::GetIO().Framerate, ImGui::GetIO().Framerate); } // 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::SetNextWindowPos(ImVec2(650, 20), ImGuiSetCondition_FirstUseEver); ImGui::ShowTestWindow(&show_test_window); } // Rendering glViewport(0, 0, (int)io.DisplaySize.x, (int)io.DisplaySize.y); glClearColor(clear_col.x, clear_col.y, clear_col.z, clear_col.w); glClear(GL_COLOR_BUFFER_BIT); ImGui::Render(); glfwSwapBuffers(window); } // Cleanup ImGui::Shutdown(); glfwTerminate(); return 0; }