Currently there is a single allocator function used in arr_t. Its
behavior depends on the values for the pointer and size arguments:
- If pointer is NULL, it should allocate new memory.
- If pointer is non-NULL and size is positive, it should resize memory.
- If size is zero, it should free memory.
All instances of arr_t use realloc for this right now. The problem
is that realloc's behavior is undefined when the size argument is zero.
On Windows and Linux, realloc will free the pointer, but on macOS this
isn't the case. This means that arr_t leaks memory on macOS.
It's best to not rely on undefined behavior like this, so let's instead
use a helper function that behaves the way we want.
The VrApi implementation now checks that X, Y, A, B buttons exist on that
specific controller. X,Y are on left; A,B on the right controller. That
mapping covers Quest Touch and Quest 2 controllers.
The current flag did not work because float shader flags are not
supported. It was also not very useful because it was per-shader
and did not use the alpha cutoff property of glTF materials.
Instead, let's turn the shader flag into an enable/disable boolean,
and add a scalar material property named "alphacutoff" that gets
read by the glTF importer.
When the alphaCutoff flag is enabled, the material property will be
compared against the pixel's alpha value to decide whether it should
get discarded.
- When calling lovr.graphics.stencil, the color mask is initially
disabled, and gets restored to its initial state afterwards.
- However, when it's restored, it uses lovrGraphicsSetColorMask, which
just sets shadow state that doesn't make it all the way to GL until
another draw is done.
- The consequence of this is that if you call .stencil and then don't do
a draw, any clears that happen will use the old (disabled) color mask,
preventing the color buffer from being cleared.
- The solution here is to lower the color mask change down into opengl.c
where it can directly hit OpenGL.