This CL splits out the code in RTCI420Shader.mm for uploading byte
buffers to textures into its own class RTCI420TextureCache. The purpose
is to prepare for allowing clients to inject their own shaders.
RTCI420TextureCache will be used in the generic code, while the actual
shaders in RTCI420Shader will be customizable by the client.
BUG=webrtc:7473
Review-Url: https://codereview.webrtc.org/2842453002
Cr-Commit-Position: refs/heads/master@{#17882}
This CL adds support in RTCEAGLVideoView for rendering CVPixelBuffers as
OpenGL ES textures directly, compared to the current code that first
converts the CVPixelBuffers to I420, and then reuploads them as
textures. This is only supported on iOS with the use of a
CVOpenGLESTextureCache.
The I420 rendering and native rendering are separated in two different
implementations of a simple shader interface:
@protocol Shader
- (BOOL)drawFrame:(RTCVideoFrame*)frame;
@end
GL resources are allocated when the shader is instantiated and released
when the shader is destroyed. RTCEAGLVideoView will lazily instantiate
the necessary shader when it receives the first frame of that kind. This
is primarily done to avoid allocating GL resources for both I420 and
native rendering.
Some other changes are:
- Print GL shader compilation errors.
- Remove updateTextureSizesForFrame() function. The textures will
resize automatically anyway when the texture data is uploaded with
glTexImage2D().
patch from issue 2154243002 at patchset 140001 (http://crrev.com/2154243002#ps140001)
Continuing magjed@'s work since he is OOO this week.
BUG=
Review-Url: https://codereview.webrtc.org/2202823004
Cr-Commit-Position: refs/heads/master@{#13668}
