1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
//! ImGui input handling for Glfw.
//!
//! # Example use
//! You can run this example with `cargo run --example helloworld`
//! ```rust
//! # use glfw::Context;
//! # use imgui::{im_str, FontGlyphRange, ImFontConfig, ImGui, ImGuiCond};
//! use imgui_glfw_rs::ImguiGLFW;
//!
//! fn main() {
//!     // Initialize imgui and glfw.
//!     // { ... }
//! #     let mut glfw = glfw::init(glfw::FAIL_ON_ERRORS).unwrap();
//! #     glfw.window_hint(glfw::WindowHint::ContextVersion(3, 3));
//! #
//! #     let (mut window, events) = glfw
//! #         .create_window(
//! #             1024,
//! #             768,
//! #             "imgui-glfw-rs example",
//! #             glfw::WindowMode::Windowed,
//! #         )
//! #         .expect("Failed to create window");
//! #
//! #     window.make_current();
//! #     window.set_framebuffer_size_polling(true);
//! #     window.set_cursor_pos_polling(true);
//! #     window.set_scroll_polling(true);
//! #     window.set_mouse_button_polling(true);
//! #     window.set_char_polling(true);
//! #     window.set_key_polling(true);
//! #
//! #     gl::load_with(|symbol| window.get_proc_address(symbol) as *const _);
//! #     unsafe {
//! #         gl::Enable(gl::BLEND);
//! #         gl::BlendFunc(gl::SRC_ALPHA, gl::ONE_MINUS_SRC_ALPHA);
//! #         gl::Enable(gl::DEPTH_TEST);
//! #         gl::DepthFunc(gl::LESS);
//! #         gl::ClearColor(0.1, 0.1, 0.1, 1.0);
//! #     }
//! #
//! #     let mut imgui = ImGui::init();
//! #
//! #     imgui.fonts().add_default_font_with_config(
//! #         ImFontConfig::new()
//! #             .oversample_h(1)
//! #             .pixel_snap_h(true)
//! #             .size_pixels(24.),
//! #     );
//! #
//! #     imgui.fonts().add_font_with_config(
//! #         include_bytes!("../res/OpenSans-Regular.ttf"),
//! #         ImFontConfig::new()
//! #             .merge_mode(true)
//! #             .oversample_h(1)
//! #             .pixel_snap_h(true)
//! #             .size_pixels(24.)
//! #             .rasterizer_multiply(1.75),
//! #         &FontGlyphRange::japanese(),
//! #     );
//! #
//! #     imgui.set_font_global_scale(1.);
//!
//!     let mut imgui_glfw = ImguiGLFW::new(&mut imgui);
//! #
//! #     let renderer =
//! #         imgui_opengl_renderer::Renderer::new(&mut imgui, |s| window.get_proc_address(s) as _);
//!
//!     while !window.should_close() {
//! #         window.make_current();
//! #
//!         unsafe {
//!             gl::Clear(gl::COLOR_BUFFER_BIT | gl::DEPTH_BUFFER_BIT);
//!         }
//!
//!         let ui = imgui_glfw.frame(&mut window, &mut imgui);
//! #
//!         // Draw your ui.
//!         // { ... }
//! #         ui.window(im_str!("Hello world"))
//! #             .size((400., 0.), ImGuiCond::Once)
//! #             .build(|| {
//! #                 ui.text(im_str!("Hello world!"));
//! #                 ui.text(im_str!("こんにちは世界!"));
//! #                 ui.text(im_str!("This...is...imgui-rs!"));
//! #                 ui.separator();
//! #                 let mouse_pos = ui.imgui().mouse_pos();
//! #                 ui.text(im_str!(
//! #                     "Mouse Position: ({:.1},{:.1})",
//! #                     mouse_pos.0,
//! #                     mouse_pos.1
//! #                 ));
//! #             });
//! #
//! #         renderer.render(ui);
//! #
//! #         window.swap_buffers();
//!
//!         // Handle imgui events
//!         glfw.poll_events();
//!         for (_, event) in glfw::flush_messages(&events) {
//!             imgui_glfw.handle_event(&mut imgui, &event);
//!         }
//!     }
//! }
//! ```

use glfw::ffi::GLFWwindow;
use glfw::{Action, Key, Modifiers, MouseButton, StandardCursor, Window, WindowEvent};
use imgui::sys as imgui_sys;
use imgui::{ImGui, ImGuiKey, ImGuiMouseCursor};
use std::os::raw::{c_char, c_void};
use std::time::Instant;

static mut WINDOW: *mut c_void = std::ptr::null_mut() as *mut c_void;

pub struct ImguiGLFW {
    last_frame: Instant,
    mouse_press: [bool; 5],
    cursor_pos: (f64, f64),
    cursor: (ImGuiMouseCursor, Option<StandardCursor>),
}

impl ImguiGLFW {
    pub fn new(imgui: &mut ImGui) -> Self {
        unsafe {
            WINDOW = glfw::ffi::glfwGetCurrentContext() as *mut c_void;
        }

        {
            let io = unsafe { &mut *imgui_sys::igGetIO() };
            io.get_clipboard_text_fn = Some(get_clipboard_text);
            io.set_clipboard_text_fn = Some(set_clipboard_text);
            io.clipboard_user_data = std::ptr::null_mut();
        }

        {
            imgui.set_imgui_key(ImGuiKey::Tab, Key::Tab as u8);
            imgui.set_imgui_key(ImGuiKey::LeftArrow, Key::Left as u8);
            imgui.set_imgui_key(ImGuiKey::RightArrow, Key::Right as u8);
            imgui.set_imgui_key(ImGuiKey::UpArrow, Key::Up as u8);
            imgui.set_imgui_key(ImGuiKey::DownArrow, Key::Down as u8);
            imgui.set_imgui_key(ImGuiKey::PageUp, Key::PageUp as u8);
            imgui.set_imgui_key(ImGuiKey::PageDown, Key::PageDown as u8);
            imgui.set_imgui_key(ImGuiKey::Home, Key::Home as u8);
            imgui.set_imgui_key(ImGuiKey::End, Key::End as u8);
            imgui.set_imgui_key(ImGuiKey::Delete, Key::Delete as u8);
            imgui.set_imgui_key(ImGuiKey::Backspace, Key::Backspace as u8);
            imgui.set_imgui_key(ImGuiKey::Enter, Key::Enter as u8);
            imgui.set_imgui_key(ImGuiKey::Escape, Key::Escape as u8);
            imgui.set_imgui_key(ImGuiKey::A, Key::A as u8);
            imgui.set_imgui_key(ImGuiKey::C, Key::C as u8);
            imgui.set_imgui_key(ImGuiKey::V, Key::V as u8);
            imgui.set_imgui_key(ImGuiKey::X, Key::X as u8);
            imgui.set_imgui_key(ImGuiKey::Y, Key::Y as u8);
            imgui.set_imgui_key(ImGuiKey::Z, Key::Z as u8);
        }

        Self {
            last_frame: Instant::now(),
            mouse_press: [false; 5],
            cursor_pos: (0., 0.),
            cursor: (ImGuiMouseCursor::None, None),
        }
    }

    pub fn handle_event(&mut self, imgui: &mut ImGui, event: &WindowEvent) {
        match *event {
            WindowEvent::MouseButton(mouse_btn, action, _) => {
                let index = match mouse_btn {
                    MouseButton::Button1 => 0,
                    MouseButton::Button2 => 1,
                    MouseButton::Button3 => 2,
                    MouseButton::Button4 => 3,
                    MouseButton::Button5 => 4,
                    _ => 0,
                };
                let press = action != Action::Release;
                self.mouse_press[index] = press;
                imgui.set_mouse_down(self.mouse_press);
            }
            WindowEvent::CursorPos(w, h) => {
                imgui.set_mouse_pos(w as f32, h as f32);
                self.cursor_pos = (w, h);
            }
            WindowEvent::Scroll(_, d) => {
                imgui.set_mouse_wheel(d as f32);
            }
            WindowEvent::Char(character) => {
                imgui.add_input_character(character);
            }
            WindowEvent::Key(key, _, action, modifier) => {
                Self::set_mod(imgui, modifier);
                if action != Action::Release {
                    imgui.set_key(key as u8, true);
                } else {
                    imgui.set_key(key as u8, false);
                }
            }
            _ => {}
        }
    }

    pub fn frame<'a>(&mut self, window: &mut Window, imgui: &'a mut ImGui) -> imgui::Ui<'a> {
        let mouse_cursor = imgui.mouse_cursor();
        if imgui.mouse_draw_cursor() || mouse_cursor == ImGuiMouseCursor::None {
            self.cursor = (ImGuiMouseCursor::None, None);
            window.set_cursor(None);
        } else if mouse_cursor != self.cursor.0 {
            let cursor = match mouse_cursor {
                ImGuiMouseCursor::None => unreachable!("mouse_cursor was None!"),
                ImGuiMouseCursor::Arrow => StandardCursor::Arrow,
                ImGuiMouseCursor::TextInput => StandardCursor::IBeam,
                ImGuiMouseCursor::Move => StandardCursor::Hand,
                ImGuiMouseCursor::ResizeNS => StandardCursor::VResize,
                ImGuiMouseCursor::ResizeEW => StandardCursor::HResize,
                ImGuiMouseCursor::ResizeNESW => StandardCursor::Crosshair,
                ImGuiMouseCursor::ResizeNWSE => StandardCursor::Crosshair,
            };

            window.set_cursor(Some(glfw::Cursor::standard(cursor)));
        }

        let now = Instant::now();
        let delta = now - self.last_frame;
        let delta_s = delta.as_secs() as f32 + delta.subsec_nanos() as f32 / 1_000_000_000.0;
        self.last_frame = now;

        let window_size = window.get_size();
        let frame_size = imgui::FrameSize {
            logical_size: (f64::from(window_size.0), f64::from(window_size.1)),
            hidpi_factor: 1.0,
        };
        imgui.frame(frame_size, delta_s)
    }

    fn set_mod(imgui: &mut ImGui, modifier: Modifiers) {
        imgui.set_key_ctrl(modifier.intersects(Modifiers::Control));
        imgui.set_key_alt(modifier.intersects(Modifiers::Alt));
        imgui.set_key_shift(modifier.intersects(Modifiers::Shift));
        imgui.set_key_super(modifier.intersects(Modifiers::Super));
    }
}

#[doc(hidden)]
pub extern "C" fn get_clipboard_text(_user_data: *mut c_void) -> *const c_char {
    unsafe { glfw::ffi::glfwGetClipboardString(WINDOW as *mut GLFWwindow) }
}

#[doc(hidden)]
#[cfg_attr(feature = "cargo-clippy", allow(clippy::not_unsafe_ptr_arg_deref))]
pub extern "C" fn set_clipboard_text(_user_data: *mut c_void, text: *const c_char) {
    unsafe {
        glfw::ffi::glfwSetClipboardString(WINDOW as *mut GLFWwindow, text);
    }
}