Add bitmap-ray and sprite-ray collision functions

[matt439]

Description

There has been growing interest in using SplashKit to perform ray-tracing in both 2D and 3D environments. However, there is a lack of ray-based functions, particularly with detecting pixel-based collisions. I have added bitmap-ray and sprite-ray functions which will allow for more advanced ray-tracing, going beyond the primitive shapes.

quad_from

This function constructs a quad around a passed-in segment. The width of the quad along the segment is also passed in as an argument.

bitmap_quad_collision

I made use of a function which I previously developed and submitted in a previous PR: #197. Unlike in the previous PR, I did not include the 4 overloads in this PR.

bitmap_bounding_circle bug fix

bitmap_ray_collision calls bitmap_bounding_circle which contains a bug. The bug was detected and fixed in a previous PR: #195. I copied the bug fix into this PR as it was necessary for accurate functioning of bitmap_ray_collision.

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

I added two new tests to sktest: one in each of test_geometry.cpp and test_sprites.cpp. These real-time graphical tests allow the user to control a ray by using the arrow keys and mouse. There are bitmaps and sprites in their respective tests which indicate whether a collision has occurred.

Testing Checklist

• Tested with sktest

Checklist

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings