rlgl module has been completely redesigned to move Mesh/Material structures to [models] module. Still some work to do, broken elements:
 - [models] OpenGL 1.1 mesh rendering: DrawMesh()
 - [models] Mesh Instancing: DrawMeshInstanced()
 - [models] Stereo rendering: DrawMesh()
 - [models] GL_FLOAT, GL_UNSIGNED_INT exposed
 - [models] GenMeshCustom()
 - [rlgl] GenTexture*() functions removal?

* adds DrawTexturedPoly with example

* the actual example ... ahem

* moved DrawTexturePoly to textures function and example
NB function name changed to fit with other DrawTextureXXX functions
(no "d" )

Co-authored-by: codifies <you@example.com>

Co-authored-by: Jeffery Myers <JefMyers@blizzard.com>

This is a very simple and specific implementation that should be better addressed by the users

Function analyzed using RenderDoc. It's a complex function and could require many triangles for the corners but it seems overall it's quite optimized!

- The vertices did not map to where I expected causing rotation to be
off by 90 degrees. I reorganized the vertices making it easier to
reason about which fixes this.
- The order for drawing is now topLeft, bottomLeft, bottomRight,
topRight.

The Raylib root Makefile for PLATFORM=PLATFORM_WEB is assumed to
run in Windows environments, which makes it incorrectly set the
PATH variable, so Linux (and possibly other) environments are not
able to find binaries from EMSDK_PATH.

Fix this by checking which PLATFORM_OS and configure PATH
accordingly.

Co-authored-by: Jeffery Myers <JefMyers@blizzard.com>

- Many functions renamed to follow rl*() convention
- Some internal functions exposed in the API
- Some functionality moved to other modules
- Reorganized all functions by categories
- Make sure it keeps working with OpenGL 1.1 and 2.1

* Add loop functions for music files.
Tell xm tracker to loop tracker when loop state changes.
Don't let looped xm tracker streams restart, they are infinite
Use modulo to make time tracker for xm looped streams work correctly.

* Remove loop functions, set XM loop in update based on flag.
Formatting cleanups.

Co-authored-by: Jeffery Myers <JefMyers@blizzard.com>

* Init MinAudio to a sample rate of 0 to let the device pick the rate.
Read the rate from the device after it starts up.
Convert AUDIO_DEVICE_SAMPLE_RATE from a #def into an int, that is set from the device's rate
Set all sample systems to use the AUDIO_DEVICE_SAMPLE_RATE as the target rate to minimize resampling.

* use device sample rate instead of separate var
let config define a device sample rate if it wants to, but let the default be 0 for native rate.

* Don't use fixed sample rates for tracker files.
Remove config default audio buffer size and replace with a function that computes one for a reasonable frame rate at the output sample rate.

- Some rlgl functions have been moved to core
 - Some functions have been made internal to rlgl
 - rlgl functions prefixed with rl*()

This appears to fix the issue with macOS windows opening with the wrong scale.

Vr simulator has been moved to core module and completely redesigned. Now user is in charge of stereo-render fbo and also in full control of distortion shader. Code is a bit more complex but better aligned with other raylib examples.

* Optimize DrawTexturePro and DrawRectanglePro transformations
- Add check so rotation is only applied if rotation != 0.0f.
- Replace matrix usage by calculating the vertex data directly.

* Fix error with windows build and trim whitespace

Co-authored-by: Simon <simon@frithrah.com>

This function could be confusing depending on the context, it's better to let the user track the current active cursor

Simplified some code

Now enum names are more consistent between them.

Just assigned a fixed memory size for custom Material parameters in case of being required, so we shouldn't worry about allocating/freeing them.

Checking for extension and enabling it if available