This adds a conformance test which renders a rectangle texture using
the two wrap modes clamp-to-edge and repeat. It then verifies that the
correct region of the texture is drawn for the texture coordinates
that are > 1.0.
The test currently always fails. The cogl_framebuffer_draw_rectangle
function is documented to always take normalized texture coordinates
regardless of the coordinate system of the texture. This works
correctly if all of the texture coordinates are in the range [0.0,1.0]
because cogl-primitives uses a different code path in that case.
However if the multiple-quad code path is taken then the coordinates
actually need to un-normalized for it to work.
There is a comment in cogl_meta_texture_foreach_in_region() which
implies that the incoming coordinates should always be normalized.
The documentation for the callback says that the resulting sub-texture
coordinates will always be in the coordinate system of the low-level
texture. However it doesn't work out like this because the meta
texture function uses the span iterating function which always returns
normalized coordinates. It looks like there needs to be some more
conversions going on somewhere.
Reviewed-by: Robert Bragg <robert@linux.intel.com>
(cherry picked from commit d2059bb32b8015060e10f41dbbb68d4230b47ddb)
1e6ec66330