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https://github.com/Drezil/imgui.git
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258 lines
9.3 KiB
C++
258 lines
9.3 KiB
C++
// ImGui SDL2 binding with OpenGL
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// https://github.com/ocornut/imgui
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#include <SDL.h>
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#include <SDL_syswm.h>
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#include <SDL_opengl.h>
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#include <imgui.h>
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#include "imgui_impl_sdl.h"
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// Data
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static double g_Time = 0.0f;
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static bool g_MousePressed[3] = { false, false, false };
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static float g_MouseWheel = 0.0f;
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static GLuint g_FontTexture = 0;
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// This is the main rendering function that you have to implement and provide to ImGui (via setting up 'RenderDrawListsFn' in the ImGuiIO structure)
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// If text or lines are blurry when integrating ImGui in your engine:
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// - in your Render function, try translating your projection matrix by (0.5f,0.5f) or (0.375f,0.375f)
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void ImGui_ImplSdl_RenderDrawLists(ImDrawData* draw_data)
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{
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// We are using the OpenGL fixed pipeline to make the example code simpler to read!
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// A probable faster way to render would be to collate all vertices from all cmd_lists into a single vertex buffer.
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// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers.
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glPushAttrib(GL_ENABLE_BIT | GL_COLOR_BUFFER_BIT | GL_TRANSFORM_BIT);
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glEnable(GL_BLEND);
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glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
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glDisable(GL_CULL_FACE);
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glDisable(GL_DEPTH_TEST);
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glEnable(GL_SCISSOR_TEST);
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glEnableClientState(GL_VERTEX_ARRAY);
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glEnableClientState(GL_TEXTURE_COORD_ARRAY);
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glEnableClientState(GL_COLOR_ARRAY);
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glEnable(GL_TEXTURE_2D);
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//glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context
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// Setup orthographic projection matrix
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const float width = ImGui::GetIO().DisplaySize.x;
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const float height = ImGui::GetIO().DisplaySize.y;
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glMatrixMode(GL_PROJECTION);
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glPushMatrix();
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glLoadIdentity();
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glOrtho(0.0f, width, height, 0.0f, -1.0f, +1.0f);
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glMatrixMode(GL_MODELVIEW);
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glPushMatrix();
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glLoadIdentity();
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// Render command lists
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#define OFFSETOF(TYPE, ELEMENT) ((size_t)&(((TYPE *)0)->ELEMENT))
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for (int n = 0; n < draw_data->CmdListsCount; n++)
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{
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const ImDrawList* cmd_list = draw_data->CmdLists[n];
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const unsigned char* vtx_buffer = (const unsigned char*)&cmd_list->VtxBuffer.front();
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const ImDrawIdx* idx_buffer = &cmd_list->IdxBuffer.front();
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glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + OFFSETOF(ImDrawVert, pos)));
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glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (void*)(vtx_buffer + OFFSETOF(ImDrawVert, uv)));
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glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (void*)(vtx_buffer + OFFSETOF(ImDrawVert, col)));
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for (int cmd_i = 0; cmd_i < cmd_list->CmdBuffer.size(); cmd_i++)
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{
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const ImDrawCmd* pcmd = &cmd_list->CmdBuffer[cmd_i];
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if (pcmd->UserCallback)
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{
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pcmd->UserCallback(cmd_list, pcmd);
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}
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else
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{
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glBindTexture(GL_TEXTURE_2D, (GLuint)(intptr_t)pcmd->TextureId);
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glScissor((int)pcmd->ClipRect.x, (int)(height - pcmd->ClipRect.w), (int)(pcmd->ClipRect.z - pcmd->ClipRect.x), (int)(pcmd->ClipRect.w - pcmd->ClipRect.y));
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glDrawElements(GL_TRIANGLES, (GLsizei)pcmd->ElemCount, GL_UNSIGNED_SHORT, idx_buffer);
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}
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idx_buffer += pcmd->ElemCount;
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}
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}
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#undef OFFSETOF
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// Restore modified state
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glDisableClientState(GL_COLOR_ARRAY);
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glDisableClientState(GL_TEXTURE_COORD_ARRAY);
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glDisableClientState(GL_VERTEX_ARRAY);
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glBindTexture(GL_TEXTURE_2D, 0);
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glMatrixMode(GL_MODELVIEW);
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glPopMatrix();
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glMatrixMode(GL_PROJECTION);
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glPopMatrix();
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glPopAttrib();
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}
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static const char* ImGui_ImplSdl_GetClipboardText()
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{
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return SDL_GetClipboardText();
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}
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static void ImGui_ImplSdl_SetClipboardText(const char* text)
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{
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SDL_SetClipboardText(text);
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}
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bool ImGui_ImplSdl_ProcessEvent(SDL_Event* event)
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{
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ImGuiIO& io = ImGui::GetIO();
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switch (event->type)
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{
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case SDL_MOUSEWHEEL:
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{
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if (event->wheel.y > 0)
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g_MouseWheel = 1;
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if (event->wheel.y < 0)
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g_MouseWheel = -1;
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return true;
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}
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case SDL_MOUSEBUTTONDOWN:
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{
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if (event->button.button == SDL_BUTTON_LEFT) g_MousePressed[0] = true;
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if (event->button.button == SDL_BUTTON_RIGHT) g_MousePressed[1] = true;
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if (event->button.button == SDL_BUTTON_MIDDLE) g_MousePressed[2] = true;
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return true;
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}
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case SDL_TEXTINPUT:
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{
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ImGuiIO& io = ImGui::GetIO();
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io.AddInputCharactersUTF8(event->text.text);
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return true;
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}
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case SDL_KEYDOWN:
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case SDL_KEYUP:
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{
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int key = event->key.keysym.sym & ~SDLK_SCANCODE_MASK;
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io.KeysDown[key] = (event->type == SDL_KEYDOWN);
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io.KeyShift = ((SDL_GetModState() & KMOD_SHIFT) != 0);
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io.KeyCtrl = ((SDL_GetModState() & KMOD_CTRL) != 0);
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io.KeyAlt = ((SDL_GetModState() & KMOD_ALT) != 0);
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return true;
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}
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}
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return false;
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}
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bool ImGui_ImplSdl_CreateDeviceObjects()
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{
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ImGuiIO& io = ImGui::GetIO();
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// Build texture
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unsigned char* pixels;
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int width, height;
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io.Fonts->GetTexDataAsAlpha8(&pixels, &width, &height);
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// Create texture
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glGenTextures(1, &g_FontTexture);
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glBindTexture(GL_TEXTURE_2D, g_FontTexture);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
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glTexParameteri(GL_TEXTURE_2D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
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glTexImage2D(GL_TEXTURE_2D, 0, GL_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, pixels);
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// Store our identifier
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io.Fonts->TexID = (void *)(intptr_t)g_FontTexture;
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// Cleanup (don't clear the input data if you want to append new fonts later)
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io.Fonts->ClearInputData();
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io.Fonts->ClearTexData();
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return true;
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}
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void ImGui_ImplSdl_InvalidateDeviceObjects()
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{
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if (g_FontTexture)
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{
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glDeleteTextures(1, &g_FontTexture);
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ImGui::GetIO().Fonts->TexID = 0;
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g_FontTexture = 0;
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}
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}
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bool ImGui_ImplSdl_Init(SDL_Window *window)
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{
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ImGuiIO& io = ImGui::GetIO();
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io.KeyMap[ImGuiKey_Tab] = SDLK_TAB; // Keyboard mapping. ImGui will use those indices to peek into the io.KeyDown[] array.
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io.KeyMap[ImGuiKey_LeftArrow] = SDL_SCANCODE_LEFT;
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io.KeyMap[ImGuiKey_RightArrow] = SDL_SCANCODE_RIGHT;
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io.KeyMap[ImGuiKey_UpArrow] = SDL_SCANCODE_UP;
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io.KeyMap[ImGuiKey_DownArrow] = SDL_SCANCODE_DOWN;
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io.KeyMap[ImGuiKey_PageUp] = SDL_SCANCODE_PAGEUP;
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io.KeyMap[ImGuiKey_PageDown] = SDL_SCANCODE_PAGEDOWN;
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io.KeyMap[ImGuiKey_Home] = SDL_SCANCODE_HOME;
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io.KeyMap[ImGuiKey_End] = SDL_SCANCODE_END;
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io.KeyMap[ImGuiKey_Delete] = SDLK_DELETE;
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io.KeyMap[ImGuiKey_Backspace] = SDLK_BACKSPACE;
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io.KeyMap[ImGuiKey_Enter] = SDLK_RETURN;
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io.KeyMap[ImGuiKey_Escape] = SDLK_ESCAPE;
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io.KeyMap[ImGuiKey_A] = SDLK_a;
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io.KeyMap[ImGuiKey_C] = SDLK_c;
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io.KeyMap[ImGuiKey_V] = SDLK_v;
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io.KeyMap[ImGuiKey_X] = SDLK_x;
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io.KeyMap[ImGuiKey_Y] = SDLK_y;
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io.KeyMap[ImGuiKey_Z] = SDLK_z;
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io.RenderDrawListsFn = ImGui_ImplSdl_RenderDrawLists; // Alternatively you can set this to NULL and call ImGui::GetDrawData() after ImGui::Render() to get the same ImDrawData pointer.
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io.SetClipboardTextFn = ImGui_ImplSdl_SetClipboardText;
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io.GetClipboardTextFn = ImGui_ImplSdl_GetClipboardText;
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#ifdef _WIN32
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SDL_SysWMinfo wmInfo;
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SDL_VERSION(&wmInfo.version);
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SDL_GetWindowWMInfo(window, &wmInfo);
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io.ImeWindowHandle = wmInfo.info.win.window;
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#endif
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return true;
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}
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void ImGui_ImplSdl_Shutdown()
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{
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ImGui_ImplSdl_InvalidateDeviceObjects();
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ImGui::Shutdown();
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}
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void ImGui_ImplSdl_NewFrame(SDL_Window *window)
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{
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if (!g_FontTexture)
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ImGui_ImplSdl_CreateDeviceObjects();
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ImGuiIO& io = ImGui::GetIO();
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// Setup display size (every frame to accommodate for window resizing)
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int w, h;
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SDL_GetWindowSize(window, &w, &h);
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io.DisplaySize = ImVec2((float)w, (float)h);
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// Setup time step
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Uint32 time = SDL_GetTicks();
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double current_time = time / 1000.0;
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io.DeltaTime = g_Time > 0.0 ? (float)(current_time - g_Time) : (float)(1.0f/60.0f);
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g_Time = current_time;
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// Setup inputs
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// (we already got mouse wheel, keyboard keys & characters from glfw callbacks polled in glfwPollEvents())
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int mx, my;
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Uint32 mouseMask = SDL_GetMouseState(&mx, &my);
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if (SDL_GetWindowFlags(window) & SDL_WINDOW_MOUSE_FOCUS)
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io.MousePos = ImVec2((float)mx, (float)my); // Mouse position, in pixels (set to -1,-1 if no mouse / on another screen, etc.)
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else
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io.MousePos = ImVec2(-1,-1);
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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.
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io.MouseDown[1] = g_MousePressed[1] || (mouseMask & SDL_BUTTON(SDL_BUTTON_RIGHT)) != 0;
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io.MouseDown[2] = g_MousePressed[2] || (mouseMask & SDL_BUTTON(SDL_BUTTON_MIDDLE)) != 0;
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g_MousePressed[0] = g_MousePressed[1] = g_MousePressed[2] = false;
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io.MouseWheel = g_MouseWheel;
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g_MouseWheel = 0.0f;
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// Hide OS mouse cursor if ImGui is drawing it
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SDL_ShowCursor(io.MouseDrawCursor ? 0 : 1);
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// Start the frame
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ImGui::NewFrame();
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}
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