Android Game Programming by Example

Drawing the scene

As we will see, drawing a bitmap is really trivial. But the coordinate system that we use to draw our graphics onto needs a brief explanation.

Plotting and drawing

When we draw a Bitmap object to the screen, we pass in the coordinates we want to draw the object at. The available coordinates of a given Android device depend on the resolution of its screen.

For example, the Samsung Galaxy S4 phone has a screen resolution of 1920 pixels (across) by 1080 pixels (down) when held in a landscape view.

The numbering system of these coordinates starts in the top-left hand corner at 0,0 and proceeds down and to the right until the bottom right corner is pixel 1919, 1079. The apparent 1 pixel disparity between 1920/ 1919 and 1080/ 1079 is because ...