Canvas and drawing

[jair-pereira]

@rithgroove

Could you explain a bit how is the logic behind the drawing on the canvas?
I ask because I want to (1) remove some boilerplaite code
e.g.:

x = (node.coordinate.lon - self.canvasOrigin[0]) * self.scale + self.viewPort[0]
y = (self.canvasSize[1]-( node.coordinate.lat - self.canvasOrigin[1])) * self.scale + self.viewPort[1]

(2) add something similar to a camera, where we apply all transformations to the camera instead of applying to every object that we draw

[rithgroove]

• Coordinate: The coordinate you wanted to draw
• Canvas Origin: The latitude and longitude of the bottom-left-most of the whole map downloaded from Open Street Map (Used to set the boundary so we did not scroll outside the simulated area.
• **View Port": The top left-most of the canvas area. so if you wanted to shift horizontally you add the horizontal translation to the viewPort[0]. viewPort[1] is the vertical axis.
• Scale: is the initial scale so that the image is not so small because the map data used latitude longitude. Right now the value never changed because we used different way to zoom in and zoom out. IIRC