abstreet/ezgui/src/canvas.rs

178 lines
5.4 KiB
Rust

// Copyright 2018 Google LLC, licensed under http://www.apache.org/licenses/LICENSE-2.0
use aabb_quadtree::geom::{Point, Rect};
use geom::Pt2D;
use graphics::Transformed;
use piston::input::{
Button, Event, MouseButton, MouseCursorEvent, MouseScrollEvent, PressEvent, ReleaseEvent,
};
use piston::window::Size;
use {text, GfxCtx, TextOSD};
const ZOOM_SPEED: f64 = 0.1;
pub struct Canvas {
// All of these f64's are in screen-space, so do NOT use Pt2D.
// Public for saving/loading... should probably do better
pub cam_x: f64,
pub cam_y: f64,
pub cam_zoom: f64,
cursor_x: f64,
cursor_y: f64,
left_mouse_drag_from: Option<[f64; 2]>,
pub window_size: Size,
}
impl Canvas {
pub fn new() -> Canvas {
Canvas {
cam_x: 0.0,
cam_y: 0.0,
cam_zoom: 1.0,
cursor_x: 0.0,
cursor_y: 0.0,
left_mouse_drag_from: None,
window_size: Size {
width: 0,
height: 0,
},
}
}
pub fn is_dragging(&self) -> bool {
self.left_mouse_drag_from.is_some()
}
pub fn handle_event(&mut self, ev: &Event) {
if let Some(pos) = ev.mouse_cursor_args() {
self.cursor_x = pos[0];
self.cursor_y = pos[1];
if let Some(click) = self.left_mouse_drag_from {
self.cam_x += click[0] - pos[0];
self.cam_y += click[1] - pos[1];
self.left_mouse_drag_from = Some(pos);
}
}
if let Some(Button::Mouse(MouseButton::Left)) = ev.press_args() {
self.left_mouse_drag_from = Some([self.cursor_x, self.cursor_y]);
}
if let Some(Button::Mouse(MouseButton::Left)) = ev.release_args() {
self.left_mouse_drag_from = None;
}
if let Some(scroll) = ev.mouse_scroll_args() {
// Zoom slower at low zooms, faster at high.
let delta = scroll[1] * ZOOM_SPEED * self.cam_zoom;
self.zoom_towards_mouse(delta);
}
}
pub fn start_drawing(&mut self, g: &mut GfxCtx, window_size: Size) {
self.window_size = window_size;
g.ctx = g
.orig_ctx
.trans(-self.cam_x, -self.cam_y)
.zoom(self.cam_zoom)
}
pub fn draw_mouse_tooltip(&self, g: &mut GfxCtx, lines: &[String]) {
let mut osd = TextOSD::new();
for l in lines {
osd.add_line(l.clone());
}
let (width, height) = osd.dims(g);
let x1 = self.cursor_x - (width / 2.0);
let y1 = self.cursor_y - (height / 2.0);
text::draw_text_bubble(g, (x1, y1), osd);
}
// at the bottom-left of the screen
pub fn draw_osd_notification(&self, g: &mut GfxCtx, osd: TextOSD) {
if osd.is_empty() {
return;
}
let (_, height) = osd.dims(g);
let y1 = f64::from(self.window_size.height) - height;
text::draw_text_bubble(g, (0.0, y1), osd);
}
pub fn draw_centered_text(&self, g: &mut GfxCtx, osd: TextOSD) {
if osd.is_empty() {
return;
}
let (width, height) = osd.dims(g);
let x1 = (f64::from(self.window_size.width) - width) / 2.0;
let y1 = (f64::from(self.window_size.height) - height) / 2.0;
text::draw_text_bubble(g, (x1, y1), osd);
}
pub fn draw_text_at(&self, g: &mut GfxCtx, lines: &[String], pt: Pt2D) {
let mut osd = TextOSD::new();
for l in lines {
osd.add_line(l.clone());
}
text::draw_text_bubble(g, self.map_to_screen(pt), osd);
}
fn zoom_towards_mouse(&mut self, delta_zoom: f64) {
let old_zoom = self.cam_zoom;
self.cam_zoom += delta_zoom;
if self.cam_zoom <= ZOOM_SPEED {
self.cam_zoom = ZOOM_SPEED;
}
// Make screen_to_map of cursor_{x,y} still point to the same thing after zooming.
self.cam_x = ((self.cam_zoom / old_zoom) * (self.cursor_x + self.cam_x)) - self.cursor_x;
self.cam_y = ((self.cam_zoom / old_zoom) * (self.cursor_y + self.cam_y)) - self.cursor_y;
}
pub fn get_cursor_in_map_space(&self) -> Pt2D {
self.screen_to_map((self.cursor_x, self.cursor_y))
}
pub fn screen_to_map(&self, (x, y): (f64, f64)) -> Pt2D {
Pt2D::new(
(x + self.cam_x) / self.cam_zoom,
(y + self.cam_y) / self.cam_zoom,
)
}
pub fn center_on_map_pt(&mut self, pt: Pt2D) {
self.cam_x = (pt.x() * self.cam_zoom) - (f64::from(self.window_size.width) / 2.0);
self.cam_y = (pt.y() * self.cam_zoom) - (f64::from(self.window_size.height) / 2.0);
}
fn map_to_screen(&self, pt: Pt2D) -> (f64, f64) {
(
(pt.x() * self.cam_zoom) - self.cam_x,
(pt.y() * self.cam_zoom) - self.cam_y,
)
}
// little weird to return an aabb_quadtree type here. need standard geometry types
pub fn get_screen_bbox(&self) -> Rect {
let top_left = self.screen_to_map((0.0, 0.0));
let bottom_right = self.screen_to_map((
f64::from(self.window_size.width),
f64::from(self.window_size.height),
));
Rect {
top_left: Point {
x: top_left.x() as f32,
y: top_left.y() as f32,
},
bottom_right: Point {
x: bottom_right.x() as f32,
y: bottom_right.y() as f32,
},
}
}
}