mirror of
https://github.com/Drezil/imgui.git
synced 2024-11-15 01:17:00 +00:00
292 lines
12 KiB
C++
292 lines
12 KiB
C++
// ImGui SDL2 binding with OpenGL
|
|
// In this binding, ImTextureID is used to store an OpenGL 'GLuint' texture identifier. Read the FAQ about ImTextureID in imgui.cpp.
|
|
// (SDL is a cross-platform general purpose library for handling windows, inputs, OpenGL/Vulkan graphics context creation, etc.)
|
|
|
|
// *DO NOT USE THIS CODE IF YOUR CODE/ENGINE IS USING MODERN OPENGL*
|
|
// This is mostly provided as a reference to learn how ImGui integration works, because it is easier to read.
|
|
// If your code is using GL3+ context or any semi modern OpenGL calls, using this is likely to make everything
|
|
// more complicated, will require your code to reset every single OpenGL attributes to their initial state,
|
|
// and might confuse your GPU driver. Prefer using sdl_opengl3_example.
|
|
// The GL2 code is unable to reset attributes or even call e.g. "glUseProgram(0)" because they don't exist in that API.
|
|
|
|
// 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 <SDL.h>
|
|
#include <SDL_syswm.h>
|
|
#include <SDL_opengl.h>
|
|
#include <imgui.h>
|
|
#include "imgui_impl_sdl.h"
|
|
|
|
// 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;
|
|
|
|
// This is the main rendering function that you have to implement and provide to ImGui (via setting up 'RenderDrawListsFn' in the ImGuiIO structure)
|
|
// Note that this implementation is little overcomplicated because we are saving/setting up/restoring every OpenGL state explicitly, in order to be able to run within any OpenGL engine that doesn't do so.
|
|
// 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_ImplSdl_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);
|
|
|
|
// We are using the OpenGL fixed pipeline to make the example code simpler to read!
|
|
// Setup render state: alpha-blending enabled, no face culling, no depth testing, scissor enabled, vertex/texcoord/color pointers, polygon fill.
|
|
GLint last_texture; glGetIntegerv(GL_TEXTURE_BINDING_2D, &last_texture);
|
|
GLint last_polygon_mode[2]; glGetIntegerv(GL_POLYGON_MODE, last_polygon_mode);
|
|
GLint last_viewport[4]; glGetIntegerv(GL_VIEWPORT, last_viewport);
|
|
GLint last_scissor_box[4]; glGetIntegerv(GL_SCISSOR_BOX, last_scissor_box);
|
|
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);
|
|
glPolygonMode(GL_FRONT_AND_BACK, GL_FILL);
|
|
//glUseProgram(0); // You may want this if using this code in an OpenGL 3+ context where shaders may be bound
|
|
|
|
// Setup viewport, orthographic projection matrix
|
|
glViewport(0, 0, (GLsizei)fb_width, (GLsizei)fb_height);
|
|
glMatrixMode(GL_PROJECTION);
|
|
glPushMatrix();
|
|
glLoadIdentity();
|
|
glOrtho(0.0f, io.DisplaySize.x, io.DisplaySize.y, 0.0f, -1.0f, +1.0f);
|
|
glMatrixMode(GL_MODELVIEW);
|
|
glPushMatrix();
|
|
glLoadIdentity();
|
|
|
|
// Render command lists
|
|
#define OFFSETOF(TYPE, ELEMENT) ((size_t)&(((TYPE *)0)->ELEMENT))
|
|
for (int n = 0; n < draw_data->CmdListsCount; n++)
|
|
{
|
|
const ImDrawList* cmd_list = draw_data->CmdLists[n];
|
|
const ImDrawVert* vtx_buffer = cmd_list->VtxBuffer.Data;
|
|
const ImDrawIdx* idx_buffer = cmd_list->IdxBuffer.Data;
|
|
glVertexPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + OFFSETOF(ImDrawVert, pos)));
|
|
glTexCoordPointer(2, GL_FLOAT, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + OFFSETOF(ImDrawVert, uv)));
|
|
glColorPointer(4, GL_UNSIGNED_BYTE, sizeof(ImDrawVert), (const GLvoid*)((const char*)vtx_buffer + OFFSETOF(ImDrawVert, col)));
|
|
|
|
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);
|
|
}
|
|
idx_buffer += pcmd->ElemCount;
|
|
}
|
|
}
|
|
#undef OFFSETOF
|
|
|
|
// Restore modified state
|
|
glDisableClientState(GL_COLOR_ARRAY);
|
|
glDisableClientState(GL_TEXTURE_COORD_ARRAY);
|
|
glDisableClientState(GL_VERTEX_ARRAY);
|
|
glBindTexture(GL_TEXTURE_2D, (GLuint)last_texture);
|
|
glMatrixMode(GL_MODELVIEW);
|
|
glPopMatrix();
|
|
glMatrixMode(GL_PROJECTION);
|
|
glPopMatrix();
|
|
glPopAttrib();
|
|
glPolygonMode(GL_FRONT, last_polygon_mode[0]); glPolygonMode(GL_BACK, last_polygon_mode[1]);
|
|
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_ImplSdl_GetClipboardText(void*)
|
|
{
|
|
return SDL_GetClipboardText();
|
|
}
|
|
|
|
static void ImGui_ImplSdl_SetClipboardText(void*, const char* text)
|
|
{
|
|
SDL_SetClipboardText(text);
|
|
}
|
|
|
|
bool ImGui_ImplSdlGL2_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;
|
|
}
|
|
|
|
bool ImGui_ImplSdlGL2_CreateDeviceObjects()
|
|
{
|
|
// Build texture atlas
|
|
ImGuiIO& io = ImGui::GetIO();
|
|
unsigned char* pixels;
|
|
int width, height;
|
|
io.Fonts->GetTexDataAsAlpha8(&pixels, &width, &height);
|
|
|
|
// 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_ALPHA, width, height, 0, GL_ALPHA, GL_UNSIGNED_BYTE, pixels);
|
|
|
|
// Store our identifier
|
|
io.Fonts->TexID = (void *)(intptr_t)g_FontTexture;
|
|
|
|
// Restore state
|
|
glBindTexture(GL_TEXTURE_2D, last_texture);
|
|
|
|
return true;
|
|
}
|
|
|
|
void ImGui_ImplSdlGL2_InvalidateDeviceObjects()
|
|
{
|
|
if (g_FontTexture)
|
|
{
|
|
glDeleteTextures(1, &g_FontTexture);
|
|
ImGui::GetIO().Fonts->TexID = 0;
|
|
g_FontTexture = 0;
|
|
}
|
|
}
|
|
|
|
bool ImGui_ImplSdlGL2_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_ImplSdl_RenderDrawLists; // Alternatively you can set this to NULL and call ImGui::GetDrawData() after ImGui::Render() to get the same ImDrawData pointer.
|
|
io.SetClipboardTextFn = ImGui_ImplSdl_SetClipboardText;
|
|
io.GetClipboardTextFn = ImGui_ImplSdl_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_ImplSdlGL2_Shutdown()
|
|
{
|
|
ImGui_ImplSdlGL2_InvalidateDeviceObjects();
|
|
ImGui::Shutdown();
|
|
}
|
|
|
|
void ImGui_ImplSdlGL2_NewFrame(SDL_Window *window)
|
|
{
|
|
if (!g_FontTexture)
|
|
ImGui_ImplSdlGL2_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(-FLT_MAX,-FLT_MAX);
|
|
|
|
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();
|
|
}
|