package imgui_backend import ( imgui "github.com/FooSoft/imgui-go" "github.com/FooSoft/lazarus/math" "github.com/go-gl/gl/v2.1/gl" "github.com/veandco/go-sdl2/sdl" ) type Context struct { buttonsDown [3]bool lastTime uint64 fontTexture uint32 displaySize math.Vec2i bufferSize math.Vec2i } func CreateContext(displaySize, bufferSize math.Vec2i) (*Context, error) { singleton.refCount++ if singleton.refCount == 1 { singleton.context = imgui.CreateContext(nil) keys := map[int]int{ imgui.KeyTab: sdl.SCANCODE_TAB, imgui.KeyLeftArrow: sdl.SCANCODE_LEFT, imgui.KeyRightArrow: sdl.SCANCODE_RIGHT, imgui.KeyUpArrow: sdl.SCANCODE_UP, imgui.KeyDownArrow: sdl.SCANCODE_DOWN, imgui.KeyPageUp: sdl.SCANCODE_PAGEUP, imgui.KeyPageDown: sdl.SCANCODE_PAGEDOWN, imgui.KeyHome: sdl.SCANCODE_HOME, imgui.KeyEnd: sdl.SCANCODE_END, imgui.KeyInsert: sdl.SCANCODE_INSERT, imgui.KeyDelete: sdl.SCANCODE_DELETE, imgui.KeyBackspace: sdl.SCANCODE_BACKSPACE, imgui.KeySpace: sdl.SCANCODE_BACKSPACE, imgui.KeyEnter: sdl.SCANCODE_RETURN, imgui.KeyEscape: sdl.SCANCODE_ESCAPE, imgui.KeyA: sdl.SCANCODE_A, imgui.KeyC: sdl.SCANCODE_C, imgui.KeyV: sdl.SCANCODE_V, imgui.KeyX: sdl.SCANCODE_X, imgui.KeyY: sdl.SCANCODE_Y, imgui.KeyZ: sdl.SCANCODE_Z, } // Keyboard mapping. ImGui will use those indices to peek into the io.KeysDown[] array. io := imgui.CurrentIO() for imguiKey, nativeKey := range keys { io.KeyMap(imguiKey, nativeKey) } } c := &Context{displaySize: displaySize, bufferSize: bufferSize} // Build texture atlas io := imgui.CurrentIO() image := io.Fonts().TextureDataRGBA32() // Store state var lastTexture int32 gl.GetIntegerv(gl.TEXTURE_BINDING_2D, &lastTexture) // Create texture gl.GenTextures(1, &c.fontTexture) gl.BindTexture(gl.TEXTURE_2D, c.fontTexture) gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MIN_FILTER, gl.LINEAR) gl.TexParameteri(gl.TEXTURE_2D, gl.TEXTURE_MAG_FILTER, gl.LINEAR) gl.PixelStorei(gl.UNPACK_ROW_LENGTH, 0) gl.TexImage2D(gl.TEXTURE_2D, 0, gl.RGBA, int32(image.Width), int32(image.Height), 0, gl.RGBA, gl.UNSIGNED_BYTE, image.Pixels) // Restore state gl.BindTexture(gl.TEXTURE_2D, uint32(lastTexture)) // Store texture identifier io.Fonts().SetTextureID(imgui.TextureID(c.fontTexture)) return c, nil } func (c *Context) SetDisplaySize(displaySize math.Vec2i) { c.displaySize = displaySize } func (c *Context) SetBufferSize(bufferSize math.Vec2i) { c.bufferSize = bufferSize } func (c *Context) Destroy() error { if c == nil || c.fontTexture == 0 { return nil } gl.DeleteTextures(1, &c.fontTexture) imgui.CurrentIO().Fonts().SetTextureID(0) c.fontTexture = 0 singleton.refCount-- if singleton.refCount == 0 { singleton.context.Destroy() singleton.context = nil } return nil }