+ OUTPUT_ALPHA_FORMAT_PREMULTIPLIED,
+ OUTPUT_ALPHA_FORMAT_POSTMULTIPLIED,
+};
+
+// RGBA output is nearly always packed; Y'CbCr, however, is often planar
+// due to chroma subsampling. This enum controls how add_ycbcr_output()
+// distributes the color channels between the fragment shader outputs.
+// Obviously, anything except YCBCR_OUTPUT_INTERLEAVED will be meaningless
+// unless you use render_to_fbo() and have an FBO with multiple render
+// targets attached (the other outputs will be discarded).
+enum YCbCrOutputSplitting {
+ // Only one output: Store Y'CbCr into the first three output channels,
+ // respectively, plus alpha. This is also called “chunked” or
+ // ”packed” mode.
+ YCBCR_OUTPUT_INTERLEAVED,
+
+ // Store Y' and alpha into the first output (in the red and alpha
+ // channels; effect to the others is undefined), and Cb and Cr into
+ // the first two channels of the second output. This is particularly
+ // useful if you want to end up in a format like NV12, where all the
+ // Y' samples come first and then Cb and Cr come interlevaed afterwards.
+ // You will still need to do the chroma subsampling yourself to actually
+ // get down to NV12, though.
+ YCBCR_OUTPUT_SPLIT_Y_AND_CBCR,
+
+ // Store Y' and alpha into the first output, Cb into the first channel
+ // of the second output and Cr into the first channel of the third output.
+ // (Effect on the other channels is undefined.) Essentially gives you
+ // 4:4:4 planar, or ”yuv444p”.
+ YCBCR_OUTPUT_PLANAR,
+};
+
+// Where (0,0) is taken to be in the output. If you want to render to an
+// OpenGL screen, you should keep the default of bottom-left, as that is
+// OpenGL's natural coordinate system. However, there are cases, such as if you
+// render to an FBO and read the pixels back into some other system, where
+// you'd want a top-left origin; if so, an additional flip step will be added
+// at the very end (but done in a vertex shader, so it will have zero extra
+// cost).
+//
+// Note that Movit's coordinate system in general consistently puts (0,0) in
+// the top left for _input_, no matter what you set as output origin.
+enum OutputOrigin {
+ OUTPUT_ORIGIN_BOTTOM_LEFT,
+ OUTPUT_ORIGIN_TOP_LEFT,