| // ImGui SDL2 binding with OpenGL3 |
| // In this binding, ImTextureID is used to store an OpenGL 'GLuint' texture identifier. Read the FAQ about ImTextureID in imgui.cpp. |
| |
| // You can copy and use unmodified imgui_impl_* files in your project. See main.cpp for an example of using this. |
| // If you use this binding you'll need to call 4 functions: ImGui_ImplXXXX_Init(), ImGui_ImplXXXX_NewFrame(), ImGui::Render() and ImGui_ImplXXXX_Shutdown(). |
| // If you are new to ImGui, see examples/README.txt and documentation at the top of imgui.cpp. |
| // https://github.com/ocornut/imgui |
| |
| #include "imgui.h" |
| #include "imgui_impl_sdl_gl3.h" |
| |
| // SDL,GL3W |
| #include <SDL.h> |
| #include <SDL_syswm.h> |
| #include <GL/gl3w.h> // This example is using gl3w to access OpenGL functions (because it is small). You may use glew/glad/glLoadGen/etc. whatever already works for you. |
| |
| // Data |
| static double g_Time = 0.0f; |
| static bool g_MousePressed[3] = { false, false, false }; |
| static float g_MouseWheel = 0.0f; |
| static GLuint g_FontTexture = 0; |
| static int g_ShaderHandle = 0, g_VertHandle = 0, g_FragHandle = 0; |
| static int g_AttribLocationTex = 0, g_AttribLocationProjMtx = 0; |
| static int g_AttribLocationPosition = 0, g_AttribLocationUV = 0, g_AttribLocationColor = 0; |
| static unsigned int g_VboHandle = 0, g_VaoHandle = 0, g_ElementsHandle = 0; |
| |
| // 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) |
| void ImGui_ImplSdlGL3_RenderDrawLists(ImDrawData* draw_data) |
| { |
| // Avoid rendering when minimized, scale coordinates for retina displays (screen coordinates != framebuffer coordinates) |
| ImGuiIO& io = ImGui::GetIO(); |
| int fb_width = (int)(io.DisplaySize.x * io.DisplayFramebufferScale.x); |
| int fb_height = (int)(io.DisplaySize.y * io.DisplayFramebufferScale.y); |
| if (fb_width == 0 || fb_height == 0) |
| return; |
| draw_data->ScaleClipRects(io.DisplayFramebufferScale); |
| |
| // Backup GL state |
| GLint last_active_texture; glGetIntegerv(GL_ACTIVE_TEXTURE, &last_active_texture); |
| glActiveTexture(GL_TEXTURE0); |
| GLint last_program; glGetIntegerv(GL_CURRENT_PROGRAM, &last_program); |
| GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture); |
| GLint last_array_buffer; glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer); |
| GLint last_element_array_buffer; glGetIntegerv(GL_ELEMENT_ARRAY_BUFFER_BINDING, &last_element_array_buffer); |
| GLint last_vertex_array; glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array); |
| GLint last_blend_src_rgb; glGetIntegerv(GL_BLEND_SRC_RGB, &last_blend_src_rgb); |
| GLint last_blend_dst_rgb; glGetIntegerv(GL_BLEND_DST_RGB, &last_blend_dst_rgb); |
| GLint last_blend_src_alpha; glGetIntegerv(GL_BLEND_SRC_ALPHA, &last_blend_src_alpha); |
| GLint last_blend_dst_alpha; glGetIntegerv(GL_BLEND_DST_ALPHA, &last_blend_dst_alpha); |
| GLint last_blend_equation_rgb; glGetIntegerv(GL_BLEND_EQUATION_RGB, &last_blend_equation_rgb); |
| GLint last_blend_equation_alpha; glGetIntegerv(GL_BLEND_EQUATION_ALPHA, &last_blend_equation_alpha); |
| GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport); |
| GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box); |
| GLboolean last_enable_blend = glIsEnabled(GL_BLEND); |
| GLboolean last_enable_cull_face = glIsEnabled(GL_CULL_FACE); |
| GLboolean last_enable_depth_test = glIsEnabled(GL_DEPTH_TEST); |
| GLboolean last_enable_scissor_test = glIsEnabled(GL_SCISSOR_TEST); |
| |
| // 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 viewport, orthographic projection matrix |
| glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height); |
| const float ortho_projection[4][4] = |
| { |
| { 2.0f/io.DisplaySize.x, 0.0f, 0.0f, 0.0f }, |
| { 0.0f, 2.0f/-io.DisplaySize.y, 0.0f, 0.0f }, |
| { 0.0f, 0.0f, -1.0f, 0.0f }, |
| {-1.0f, 1.0f, 0.0f, 1.0f }, |
| }; |
| glUseProgram(g_ShaderHandle); |
| glUniform1i(g_AttribLocationTex, 0); |
| glUniformMatrix4fv(g_AttribLocationProjMtx, 1, GL_FALSE, &ortho_projection[0][0]); |
| glBindVertexArray(g_VaoHandle); |
| |
| for (int n = 0; n < draw_data->CmdListsCount; n++) |
| { |
| const ImDrawList* cmd_list = draw_data->CmdLists[n]; |
| const ImDrawIdx* idx_buffer_offset = 0; |
| |
| glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle); |
| glBufferData(GL_ARRAY_BUFFER, (GLsizeiptr)cmd_list->VtxBuffer.Size * sizeof(ImDrawVert), (const GLvoid*)cmd_list->VtxBuffer.Data, GL_STREAM_DRAW); |
| |
| glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, g_ElementsHandle); |
| glBufferData(GL_ELEMENT_ARRAY_BUFFER, (GLsizeiptr)cmd_list->IdxBuffer.Size * sizeof(ImDrawIdx), (const GLvoid*)cmd_list->IdxBuffer.Data, GL_STREAM_DRAW); |
| |
| for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.Size; cmd_i++) |
| { |
| const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i]; |
| if (pcmd->UserCallback) |
| { |
| pcmd->UserCallback(cmd_list, pcmd); |
| } |
| else |
| { |
| glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId); |
| glScissor((int)pcmd->ClipRect.x, (int)(fb_height - pcmd->ClipRect.w), (int)(pcmd->ClipRect.z - pcmd->ClipRect.x), (int)(pcmd->ClipRect.w - pcmd->ClipRect.y)); |
| glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, sizeof(ImDrawIdx) == 2 ? GL_UNSIGNED_SHORT : GL_UNSIGNED_INT, idx_buffer_offset); |
| } |
| idx_buffer_offset += pcmd->ElemCount; |
| } |
| } |
| |
| // Restore modified GL state |
| glUseProgram(last_program); |
| glBindTexture(GL_TEXTURE_2D, last_texture); |
| glActiveTexture(last_active_texture); |
| glBindVertexArray(last_vertex_array); |
| glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer); |
| glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, last_element_array_buffer); |
| glBlendEquationSeparate(last_blend_equation_rgb, last_blend_equation_alpha); |
| glBlendFuncSeparate(last_blend_src_rgb, last_blend_dst_rgb, last_blend_src_alpha, last_blend_dst_alpha); |
| if (last_enable_blend) glEnable(GL_BLEND); else glDisable(GL_BLEND); |
| if (last_enable_cull_face) glEnable(GL_CULL_FACE); else glDisable(GL_CULL_FACE); |
| if (last_enable_depth_test) glEnable(GL_DEPTH_TEST); else glDisable(GL_DEPTH_TEST); |
| if (last_enable_scissor_test) glEnable(GL_SCISSOR_TEST); else glDisable(GL_SCISSOR_TEST); |
| glViewport(last_viewport[0], last_viewport[1], (GLsizei)last_viewport[2], (GLsizei)last_viewport[3]); |
| glScissor(last_scissor_box[0], last_scissor_box[1], (GLsizei)last_scissor_box[2], (GLsizei)last_scissor_box[3]); |
| } |
| |
| static const char* ImGui_ImplSdlGL3_GetClipboardText(void*) |
| { |
| return SDL_GetClipboardText(); |
| } |
| |
| static void ImGui_ImplSdlGL3_SetClipboardText(void*, const char* text) |
| { |
| SDL_SetClipboardText(text); |
| } |
| |
| bool ImGui_ImplSdlGL3_ProcessEvent(SDL_Event* event) |
| { |
| ImGuiIO& io = ImGui::GetIO(); |
| switch (event->type) |
| { |
| case SDL_MOUSEWHEEL: |
| { |
| if (event->wheel.y > 0) |
| g_MouseWheel = 1; |
| if (event->wheel.y < 0) |
| g_MouseWheel = -1; |
| return true; |
| } |
| case SDL_MOUSEBUTTONDOWN: |
| { |
| if (event->button.button == SDL_BUTTON_LEFT) g_MousePressed[0] = true; |
| if (event->button.button == SDL_BUTTON_RIGHT) g_MousePressed[1] = true; |
| if (event->button.button == SDL_BUTTON_MIDDLE) g_MousePressed[2] = true; |
| return true; |
| } |
| case SDL_TEXTINPUT: |
| { |
| io.AddInputCharactersUTF8(event->text.text); |
| return true; |
| } |
| case SDL_KEYDOWN: |
| case SDL_KEYUP: |
| { |
| int key = event->key.keysym.sym & ~SDLK_SCANCODE_MASK; |
| io.KeysDown[key] = (event->type == SDL_KEYDOWN); |
| io.KeyShift = ((SDL_GetModState() & KMOD_SHIFT) != 0); |
| io.KeyCtrl = ((SDL_GetModState() & KMOD_CTRL) != 0); |
| io.KeyAlt = ((SDL_GetModState() & KMOD_ALT) != 0); |
| io.KeySuper = ((SDL_GetModState() & KMOD_GUI) != 0); |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| void ImGui_ImplSdlGL3_CreateFontsTexture() |
| { |
| // Build texture atlas |
| ImGuiIO& io = ImGui::GetIO(); |
| unsigned char* pixels; |
| int width, height; |
| io.Fonts->GetTexDataAsRGBA32(&pixels, &width, &height); // Load as RGBA 32-bits for OpenGL3 demo because it is more likely to be compatible with user's existing shader. |
| |
| // Upload texture to graphics system |
| GLint last_texture; |
| glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture); |
| glGenTextures(1, &g_FontTexture); |
| glBindTexture(GL_TEXTURE_2D, g_FontTexture); |
| glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR); |
| glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR); |
| glPixelStorei(GL_UNPACK_ROW_LENGTH, 0); |
| glTexImage2D(GL_TEXTURE_2D, 0, GL_RGBA, width, height, 0, GL_RGBA, GL_UNSIGNED_BYTE, pixels); |
| |
| // Store our identifier |
| io.Fonts->TexID = (void *)(intptr_t)g_FontTexture; |
| |
| // Restore state |
| glBindTexture(GL_TEXTURE_2D, last_texture); |
| } |
| |
| bool ImGui_ImplSdlGL3_CreateDeviceObjects() |
| { |
| // Backup GL state |
| GLint last_texture, last_array_buffer, last_vertex_array; |
| glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture); |
| glGetIntegerv(GL_ARRAY_BUFFER_BINDING, &last_array_buffer); |
| glGetIntegerv(GL_VERTEX_ARRAY_BINDING, &last_vertex_array); |
| |
| const GLchar *vertex_shader = |
| "#version 330\n" |
| "uniform mat4 ProjMtx;\n" |
| "in vec2 Position;\n" |
| "in vec2 UV;\n" |
| "in vec4 Color;\n" |
| "out vec2 Frag_UV;\n" |
| "out vec4 Frag_Color;\n" |
| "void main()\n" |
| "{\n" |
| " Frag_UV = UV;\n" |
| " Frag_Color = Color;\n" |
| " gl_Position = ProjMtx * 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_Color;\n" |
| "out vec4 Out_Color;\n" |
| "void main()\n" |
| "{\n" |
| " Out_Color = Frag_Color * texture( Texture, Frag_UV.st);\n" |
| "}\n"; |
| |
| g_ShaderHandle = glCreateProgram(); |
| g_VertHandle = glCreateShader(GL_VERTEX_SHADER); |
| g_FragHandle = glCreateShader(GL_FRAGMENT_SHADER); |
| glShaderSource(g_VertHandle, 1, &vertex_shader, 0); |
| glShaderSource(g_FragHandle, 1, &fragment_shader, 0); |
| glCompileShader(g_VertHandle); |
| glCompileShader(g_FragHandle); |
| glAttachShader(g_ShaderHandle, g_VertHandle); |
| glAttachShader(g_ShaderHandle, g_FragHandle); |
| glLinkProgram(g_ShaderHandle); |
| |
| g_AttribLocationTex = glGetUniformLocation(g_ShaderHandle, "Texture"); |
| g_AttribLocationProjMtx = glGetUniformLocation(g_ShaderHandle, "ProjMtx"); |
| g_AttribLocationPosition = glGetAttribLocation(g_ShaderHandle, "Position"); |
| g_AttribLocationUV = glGetAttribLocation(g_ShaderHandle, "UV"); |
| g_AttribLocationColor = glGetAttribLocation(g_ShaderHandle, "Color"); |
| |
| glGenBuffers(1, &g_VboHandle); |
| glGenBuffers(1, &g_ElementsHandle); |
| |
| glGenVertexArrays(1, &g_VaoHandle); |
| glBindVertexArray(g_VaoHandle); |
| glBindBuffer(GL_ARRAY_BUFFER, g_VboHandle); |
| glEnableVertexAttribArray(g_AttribLocationPosition); |
| glEnableVertexAttribArray(g_AttribLocationUV); |
| glEnableVertexAttribArray(g_AttribLocationColor); |
| |
| #define OFFSETOF(TYPE, ELEMENT) ((size_t)&(((TYPE *)0)->ELEMENT)) |
| glVertexAttribPointer(g_AttribLocationPosition, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, pos)); |
| glVertexAttribPointer(g_AttribLocationUV, 2, GL_FLOAT, GL_FALSE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, uv)); |
| glVertexAttribPointer(g_AttribLocationColor, 4, GL_UNSIGNED_BYTE, GL_TRUE, sizeof(ImDrawVert), (GLvoid*)OFFSETOF(ImDrawVert, col)); |
| #undef OFFSETOF |
| |
| ImGui_ImplSdlGL3_CreateFontsTexture(); |
| |
| // Restore modified GL state |
| glBindTexture(GL_TEXTURE_2D, last_texture); |
| glBindBuffer(GL_ARRAY_BUFFER, last_array_buffer); |
| glBindVertexArray(last_vertex_array); |
| |
| return true; |
| } |
| |
| void ImGui_ImplSdlGL3_InvalidateDeviceObjects() |
| { |
| if (g_VaoHandle) glDeleteVertexArrays(1, &g_VaoHandle); |
| if (g_VboHandle) glDeleteBuffers(1, &g_VboHandle); |
| if (g_ElementsHandle) glDeleteBuffers(1, &g_ElementsHandle); |
| g_VaoHandle = g_VboHandle = g_ElementsHandle = 0; |
| |
| if (g_ShaderHandle && g_VertHandle) glDetachShader(g_ShaderHandle, g_VertHandle); |
| if (g_VertHandle) glDeleteShader(g_VertHandle); |
| g_VertHandle = 0; |
| |
| if (g_ShaderHandle && g_FragHandle) glDetachShader(g_ShaderHandle, g_FragHandle); |
| if (g_FragHandle) glDeleteShader(g_FragHandle); |
| g_FragHandle = 0; |
| |
| if (g_ShaderHandle) glDeleteProgram(g_ShaderHandle); |
| g_ShaderHandle = 0; |
| |
| if (g_FontTexture) |
| { |
| glDeleteTextures(1, &g_FontTexture); |
| ImGui::GetIO().Fonts->TexID = 0; |
| g_FontTexture = 0; |
| } |
| } |
| |
| bool ImGui_ImplSdlGL3_Init(SDL_Window* window) |
| { |
| ImGuiIO& io = ImGui::GetIO(); |
| io.KeyMap[ImGuiKey_Tab] = SDLK_TAB; // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array. |
| io.KeyMap[ImGuiKey_LeftArrow] = SDL_SCANCODE_LEFT; |
| io.KeyMap[ImGuiKey_RightArrow] = SDL_SCANCODE_RIGHT; |
| io.KeyMap[ImGuiKey_UpArrow] = SDL_SCANCODE_UP; |
| io.KeyMap[ImGuiKey_DownArrow] = SDL_SCANCODE_DOWN; |
| io.KeyMap[ImGuiKey_PageUp] = SDL_SCANCODE_PAGEUP; |
| io.KeyMap[ImGuiKey_PageDown] = SDL_SCANCODE_PAGEDOWN; |
| io.KeyMap[ImGuiKey_Home] = SDL_SCANCODE_HOME; |
| io.KeyMap[ImGuiKey_End] = SDL_SCANCODE_END; |
| io.KeyMap[ImGuiKey_Delete] = SDLK_DELETE; |
| io.KeyMap[ImGuiKey_Backspace] = SDLK_BACKSPACE; |
| io.KeyMap[ImGuiKey_Enter] = SDLK_RETURN; |
| io.KeyMap[ImGuiKey_Escape] = SDLK_ESCAPE; |
| io.KeyMap[ImGuiKey_A] = SDLK_a; |
| io.KeyMap[ImGuiKey_C] = SDLK_c; |
| io.KeyMap[ImGuiKey_V] = SDLK_v; |
| io.KeyMap[ImGuiKey_X] = SDLK_x; |
| io.KeyMap[ImGuiKey_Y] = SDLK_y; |
| io.KeyMap[ImGuiKey_Z] = SDLK_z; |
| |
| io.RenderDrawListsFn = ImGui_ImplSdlGL3_RenderDrawLists; // Alternatively you can set this to NULL and call ImGui::GetDrawData() after ImGui::Render() to get the same ImDrawData pointer. |
| io.SetClipboardTextFn = ImGui_ImplSdlGL3_SetClipboardText; |
| io.GetClipboardTextFn = ImGui_ImplSdlGL3_GetClipboardText; |
| io.ClipboardUserData = NULL; |
| |
| #ifdef _WIN32 |
| SDL_SysWMinfo wmInfo; |
| SDL_VERSION(&wmInfo.version); |
| SDL_GetWindowWMInfo(window, &wmInfo); |
| io.ImeWindowHandle = wmInfo.info.win.window; |
| #else |
| (void)window; |
| #endif |
| |
| return true; |
| } |
| |
| void ImGui_ImplSdlGL3_Shutdown() |
| { |
| ImGui_ImplSdlGL3_InvalidateDeviceObjects(); |
| ImGui::Shutdown(); |
| } |
| |
| void ImGui_ImplSdlGL3_NewFrame(SDL_Window* window) |
| { |
| if (!g_FontTexture) |
| ImGui_ImplSdlGL3_CreateDeviceObjects(); |
| |
| ImGuiIO& io = ImGui::GetIO(); |
| |
| // Setup display size (every frame to accommodate for window resizing) |
| int w, h; |
| int display_w, display_h; |
| SDL_GetWindowSize(window, &w, &h); |
| SDL_GL_GetDrawableSize(window, &display_w, &display_h); |
| io.DisplaySize = ImVec2((float)w, (float)h); |
| io.DisplayFramebufferScale = ImVec2(w > 0 ? ((float)display_w / w) : 0, h > 0 ? ((float)display_h / h) : 0); |
| |
| // Setup time step |
| Uint32 time = SDL_GetTicks(); |
| double current_time = time / 1000.0; |
| io.DeltaTime = g_Time > 0.0 ? (float)(current_time - g_Time) : (float)(1.0f / 60.0f); |
| g_Time = current_time; |
| |
| // Setup inputs |
| // (we already got mouse wheel, keyboard keys & characters from SDL_PollEvent()) |
| int mx, my; |
| Uint32 mouseMask = SDL_GetMouseState(&mx, &my); |
| if (SDL_GetWindowFlags(window) & SDL_WINDOW_MOUSE_FOCUS) |
| io.MousePos = ImVec2((float)mx, (float)my); // Mouse position, in pixels (set to -1,-1 if no mouse / on another screen, etc.) |
| else |
| io.MousePos = ImVec2(-1, -1); |
| |
| io.MouseDown[0] = g_MousePressed[0] || (mouseMask & SDL_BUTTON(SDL_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] = g_MousePressed[1] || (mouseMask & SDL_BUTTON(SDL_BUTTON_RIGHT)) != 0; |
| io.MouseDown[2] = g_MousePressed[2] || (mouseMask & SDL_BUTTON(SDL_BUTTON_MIDDLE)) != 0; |
| g_MousePressed[0] = g_MousePressed[1] = g_MousePressed[2] = false; |
| |
| io.MouseWheel = g_MouseWheel; |
| g_MouseWheel = 0.0f; |
| |
| // Hide OS mouse cursor if ImGui is drawing it |
| SDL_ShowCursor(io.MouseDrawCursor ? 0 : 1); |
| |
| // Start the frame |
| ImGui::NewFrame(); |
| } |