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comparison doodle/tk/pixel_model.d @ 70:0e61702c6ea6

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author "David Bryant <bagnose@gmail.com>"
date Sat, 14 Aug 2010 20:05:55 +0930
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children 0f7cf6c6f206
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69:d540f7e4af9e 70:0e61702c6ea6
1 module doodle.tk.pixel_model;
2
3 public {
4 import doodle.tk.geometry;
5 }
6
7 // FIXME consider using the term Screen instead of Pixel...
8
9 class PixelModel {
10 this(in double zoom, in Rectangle canvasBounds, in Rectangle viewBounds) {
11 _zoom = zoom;
12 _viewBounds = viewBounds;
13 _canvasBounds = canvasBounds;
14
15 _viewCentre = _canvasBounds.centre;
16 }
17
18 void consolidateCanvasBounds(in Rectangle requiredCanvasBounds) {
19 Rectangle r = pixelToModel(_viewBounds);
20 _canvasBounds = r | requiredCanvasBounds;
21 }
22
23 // For normalZoom 1.0 -> 100% means the presentation on the screen is
24 // one-to-one with real-life
25 double normalZoom(in double pixelsPerMillimetre) { return _zoom / pixelsPerMillimetre; }
26
27 Point modelToPixel(in Point model) const { return _viewBounds.centre + _zoom * (model - _viewCentre); }
28 Point pixelToModel(in Point pixel) const { return _viewCentre + (pixel - _viewBounds.centre) / _zoom; }
29 Vector modelToPixel(in Vector model) const { return _zoom * model; }
30 Vector pixelToModel(in Vector pixel) const { return pixel / _zoom; }
31 Rectangle modelToPixel(in Rectangle model) const { return Rectangle(modelToPixel(model.position), modelToPixel(model.size)); }
32 Rectangle pixelToModel(in Rectangle model) const { return Rectangle(pixelToModel(model.position), pixelToModel(model.size)); }
33
34 private {
35 // Screen units are pixels
36 // Model units are millimetres
37 double _zoom; // pixels-per-millimetre
38 Rectangle _viewBounds; // pixel: bounds of the viewport in pixels
39 Point _viewCentre; // model: where in the model is the centre of our view
40 Rectangle _canvasBounds; // model: the bounds of the canvas in millimetres
41 }
42 }