This moves all the rendering to a command list that is flushed to the GL as
necessary, making most common activities upload a single vertex buffer per
frame and dramatically reducing state changes. In pathological cases,
like Emscripten running on iOS's Safari, performance can go from a dozen
draw calls killing your performance to 1000 draw calls running smoothly.
This is work in progress, and not ready to ship. Among other things, it has
a hardcoded array that isn't checked for overflow. But the basic idea is
sound!
The only place angle is activated and causes effect is RenderCopyEx. All other
methods which use vertex shader, leave angle disabled and cause useless sin/cos
calculation in shader.
To get around shader's interface is changed to a vector that contains results
of sin and cos. To behave properly when disabled, cos value is set with offset
-1.0 making 0.0 default when deactivated.
As nice side effect it simplifies GLES2_UpdateVertexBuffer: All attributes are
vectors now.
Additional background:
* On RaspberryPi it gives a performace win for operations. Tested with
[1] numbers go down for 5-10% (not easy to estimate due to huge variation).
* SDL_RenderCopyEx was tested with [2]
* It works around left rotated display caused by low accuracy sin implemetation
in RaspberryPi/VC4 [3]
[1] https://github.com/schnitzeltony/sdl2box
[2] https://github.com/schnitzeltony/sdl2rendercopyex
[3] https://github.com/anholt/mesa/issues/110
Signed-off-by: Andreas M?ller <schnitzeltony@gmail.com>
New functions get and set the YUV colorspace conversion mode:
SDL_SetYUVConversionMode()
SDL_GetYUVConversionMode()
SDL_GetYUVConversionModeForResolution()
SDL_ConvertPixels() converts between all supported RGB and YUV formats, with SSE acceleration for converting from planar YUV formats (YV12, NV12, etc) to common RGB/RGBA formats.
Added a new test program, testyuv, to verify correctness and speed of YUV conversion functionality.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
