| // ImGui - standalone example application for OpenGL 3, using programmable pipeline |
| |
| #ifdef _MSC_VER |
| #pragma warning (disable: 4996) // 'This function or variable may be unsafe': strcpy, strdup, sprintf, vsnprintf, sscanf, fopen |
| #endif |
| |
| #include "../../imgui.h" |
| #define STB_IMAGE_IMPLEMENTATION |
| #include "../shared/stb_image.h" // stb_image.h for PNG loading |
| |
| // 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 GLuint fontTex; |
| static bool mousePressed[2] = { false, false }; |
| |
| // Shader variables |
| static int shader_handle, vert_handle, frag_handle; |
| static int texture_location, ortho_location; |
| static int position_location, uv_location, colour_location; |
| static size_t vbo_max_size = 20000; |
| static unsigned int vbo_handle, vao_handle; |
| |
| // 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: |
| // - try adjusting ImGui::GetIO().PixelCenterOffset to 0.0f or 0.5f |
| // - 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; |
| |
| // Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled |
| glEnable(GL_BLEND); |
| glBlendEquation(GL_FUNC_ADD); |
| glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); |
| glDisable(GL_CULL_FACE); |
| glDisable(GL_DEPTH_TEST); |
| glEnable(GL_SCISSOR_TEST); |
| |
| // Setup texture |
| glActiveTexture(GL_TEXTURE0); |
| glBindTexture(GL_TEXTURE_2D, fontTex); |
| |
| // Setup orthographic projection matrix |
| const float width = ImGui::GetIO().DisplaySize.x; |
| const float height = ImGui::GetIO().DisplaySize.y; |
| const float ortho_projection[4][4] = |
| { |
| { 2.0f/width, 0.0f, 0.0f, 0.0f }, |
| { 0.0f, 2.0f/-height, 0.0f, 0.0f }, |
| { 0.0f, 0.0f, -1.0f, 0.0f }, |
| { -1.0f, 1.0f, 0.0f, 1.0f }, |
| }; |
| glUseProgram(shader_handle); |
| glUniform1i(texture_location, 0); |
| glUniformMatrix4fv(ortho_location, 1, GL_FALSE, &ortho_projection[0][0]); |
| |
| // Grow our buffer according to what we need |
| size_t total_vtx_count = 0; |
| for (int n = 0; n < cmd_lists_count; n++) |
| total_vtx_count += cmd_lists[n]->vtx_buffer.size(); |
| glBindBuffer(GL_ARRAY_BUFFER, vbo_handle); |
| size_t neededBufferSize = total_vtx_count * sizeof(ImDrawVert); |
| if (neededBufferSize > vbo_max_size) |
| { |
| vbo_max_size = neededBufferSize + 5000; // Grow buffer |
| glBufferData(GL_ARRAY_BUFFER, neededBufferSize, NULL, GL_STREAM_DRAW); |
| } |
| |
| // Copy and convert all vertices into a single contiguous buffer |
| unsigned char* buffer_data = (unsigned char*)glMapBuffer(GL_ARRAY_BUFFER, GL_WRITE_ONLY); |
| if (!buffer_data) |
| return; |
| for (int n = 0; n < cmd_lists_count; n++) |
| { |
| const ImDrawList* cmd_list = cmd_lists[n]; |
| memcpy(buffer_data, &cmd_list->vtx_buffer[0], cmd_list->vtx_buffer.size() * sizeof(ImDrawVert)); |
| buffer_data += cmd_list->vtx_buffer.size() * sizeof(ImDrawVert); |
| } |
| glUnmapBuffer(GL_ARRAY_BUFFER); |
| glBindBuffer(GL_ARRAY_BUFFER, 0); |
| glBindVertexArray(vao_handle); |
| |
| int cmd_offset = 0; |
| for (int n = 0; n < cmd_lists_count; n++) |
| { |
| const ImDrawList* cmd_list = cmd_lists[n]; |
| int vtx_offset = cmd_offset; |
| const ImDrawCmd* pcmd_end = cmd_list->commands.end(); |
| for (const ImDrawCmd* pcmd = cmd_list->commands.begin(); pcmd != pcmd_end; pcmd++) |
| { |
| 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; |
| } |
| cmd_offset = vtx_offset; |
| } |
| |
| // Restore modified state |
| glBindVertexArray(0); |
| glUseProgram(0); |
| glDisable(GL_SCISSOR_TEST); |
| glBindTexture(GL_TEXTURE_2D, 0); |
| } |
| |
| 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); |
| } |
| |
| // OpenGL code based on http://open.gl tutorials |
| void InitGL() |
| { |
| glfwSetErrorCallback(glfw_error_callback); |
| |
| if (!glfwInit()) |
| exit(1); |
| |
| glfwWindowHint(GLFW_CONTEXT_VERSION_MAJOR, 3); |
| glfwWindowHint(GLFW_CONTEXT_VERSION_MINOR, 3); |
| glfwWindowHint(GLFW_OPENGL_PROFILE, GLFW_OPENGL_CORE_PROFILE); |
| |
| 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); |
| |
| glewExperimental = GL_TRUE; |
| |
| GLenum err = glewInit(); |
| if (GLEW_OK != err) |
| fprintf(stderr, "Error: %s\n", glewGetErrorString(err)); |
| |
| const GLchar *vertex_shader = |
| "#version 330\n" |
| "uniform mat4 ortho;\n" |
| "in vec2 Position;\n" |
| "in vec2 UV;\n" |
| "in vec4 Colour;\n" |
| "out vec2 Frag_UV;\n" |
| "out vec4 Frag_Colour;\n" |
| "void main()\n" |
| "{\n" |
| " Frag_UV = UV;\n" |
| " Frag_Colour = Colour;\n" |
| " gl_Position = ortho*vec4(Position.xy,0,1);\n" |
| "}\n"; |
| |
| const GLchar* fragment_shader = |
| "#version 330\n" |
| "uniform sampler2D Texture;\n" |
| "in vec2 Frag_UV;\n" |
| "in vec4 Frag_Colour;\n" |
| "out vec4 FragColor;\n" |
| "void main()\n" |
| "{\n" |
| " FragColor = Frag_Colour * texture( Texture, Frag_UV.st);\n" |
| "}\n"; |
| |
| shader_handle = glCreateProgram(); |
| vert_handle = glCreateShader(GL_VERTEX_SHADER); |
| frag_handle = glCreateShader(GL_FRAGMENT_SHADER); |
| glShaderSource(vert_handle, 1, &vertex_shader, 0); |
| glShaderSource(frag_handle, 1, &fragment_shader, 0); |
| glCompileShader(vert_handle); |
| glCompileShader(frag_handle); |
| glAttachShader(shader_handle, vert_handle); |
| glAttachShader(shader_handle, frag_handle); |
| glLinkProgram(shader_handle); |
| |
| texture_location = glGetUniformLocation(shader_handle, "Texture"); |
| ortho_location = glGetUniformLocation(shader_handle, "ortho"); |
| position_location = glGetAttribLocation(shader_handle, "Position"); |
| uv_location = glGetAttribLocation(shader_handle, "UV"); |
| colour_location = glGetAttribLocation(shader_handle, "Colour"); |
| |
| glGenBuffers(1, &vbo_handle); |
| glBindBuffer(GL_ARRAY_BUFFER, vbo_handle); |
| glBufferData(GL_ARRAY_BUFFER, vbo_max_size, NULL, GL_DYNAMIC_DRAW); |
| |
| glGenVertexArrays(1, &vao_handle); |
| glBindVertexArray(vao_handle); |
| glBindBuffer(GL_ARRAY_BUFFER, vbo_handle); |
| glEnableVertexAttribArray(position_location); |
| glEnableVertexAttribArray(uv_location); |
| glEnableVertexAttribArray(colour_location); |
| |
| glVertexAttribPointer(position_location, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, pos)); |
| glVertexAttribPointer(uv_location, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, uv)); |
| glVertexAttribPointer(colour_location, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, col)); |
| glBindVertexArray(0); |
| glBindBuffer(GL_ARRAY_BUFFER, 0); |
| } |
| |
| 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 timestep is variable) |
| io.PixelCenterOffset = 0.5f; // 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; |
| |
| // 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); |
| 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); |
| 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 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(); |
| |
| while (!glfwWindowShouldClose(window)) |
| { |
| ImGuiIO& io = ImGui::GetIO(); |
| io.MouseWheel = 0; |
| mousePressed[0] = mousePressed[1] = false; |
| 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 frame rate |
| 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::SetNextWindowPos(ImVec2(650, 20), ImGuiSetCondition_FirstUseEver); |
| 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); |
| } |
| |
| // Cleanup |
| if (vao_handle) glDeleteVertexArrays(1, &vao_handle); |
| if (vbo_handle) glDeleteBuffers(1, &vbo_handle); |
| glDetachShader(shader_handle, vert_handle); |
| glDetachShader(shader_handle, frag_handle); |
| glDeleteShader(vert_handle); |
| glDeleteShader(frag_handle); |
| glDeleteProgram(shader_handle); |
| |
| ImGui::Shutdown(); |
| glfwTerminate(); |
| |
| return 0; |
| } |