'make check' reports:
./cairo-cogl-context.c: * cairo_path_fixed_t in user coordinates that we can use to create a
./cairo-cogl-context.c: * We use this hash to lookup a cairo_cogl_path_meta_t struct which
./cairo-cogl-context.c: * need to use the cairo_path_fixed_t api to describe a rectangle in terms of
./cairo-cogl-context.c: * passed the current cairo_t context we don't have a good way
Error: some type names in the docs are not prefixed by hash sign,
neither are the only token in the doc line followed by colon.
Fix this by searching for the following regexp in the above files:
'^[^:]*:[/ ][*]\( .*[^#']\| \|^\)\<cairo[0-9a-z_]*_t\>\($\|[^:]$\|[^:].\)'
./cairo-cogl-context.c: * cairo_path_fixed_t in user coordinates that we can use to create a
./cairo-cogl-context.c: * We use this hash to lookup a cairo_cogl_path_meta_t struct which
./cairo-cogl-context.c: * need to use the cairo_path_fixed_t api to describe a rectangle in terms of
./cairo-cogl-context.c: * passed the current cairo_t context we don't have a good way
Error: some function names in the docs are not followed by parentheses.
Fix this by searching for the following regexp in the above files:
'^[^:]*:[/ ][*]\(\|[ ].*\)\([^#']\|^\)\<\(cairo_[][<>/0-9a-z_]*\>[^][<>(]\)'
Checking that source files #include "cairoint.h" first (or none)
cairo-cogl-context.c:#include "cairo-cogl-context-private.h"
These are fixed trivially by this patch.
This adds a new GPU accelerated backend for Cairo based on the Cogl 3D
graphics API.
This backend aims to support Cairo in a way that translates as naturally
as possible to using a GPU, it does not strive to compete with the
anti-aliasing quality of the image backend if it can't be done
efficiently using the GPU - raw performance isn't the only metric of
concern, so is power usage.
As an overview of how the backend works:
- fills are handled by tessellating paths into triangles
- the backend has an extra fill_rectangle drawing operation so we have
a fast-path for drawing rectangles which are so common.
- strokes are also tessellated into triangles.
- stroke and fill tessellations are cached to avoid the cpu overhead
of tessellation and cost of upload given that its common for apps to
re-draw the same path multiple times. The tessellations can survive
translations and rotations increasing the probability that they can be
re-used.
- sources and masks are handled using multi-texturing.
- clipping is handled with a scissor and the stencil buffer which
we're careful to only update when they really change.
- linear gradients are rendered to a 1d texture using a triangle
strip + interpolating color attributes. All cairo extend modes
are handled by corresponding texture sampler wrap modes without
needing programmable fragment processing.
- antialiasing should be handled using Cogl's multisampling API
XXX: This is a work in progress!!
TODO:
- handle at least basic radial gradients (No need to handle full
pdf semantics, since css, svg and canvas only allow radial gradients
defined as one circle + a point that must lie within the first
circle.) - currently we fall back to pixman for radial gradients.
- support glyph rendering with a decent glyph cache design. The
current plan is a per scaled-font growable cache texture + a
scratch cache for one-shot/short-lived glyphs.
- decide how to handle npot textures when lacking hardware support.
Current plan is to add a transparent border to npot textures and use
CLAMP_TO_EDGE for the default EXTEND_NONE semantics. For anything else
we can allocate a shadow npot texture and scale the original to fit
that so we can map extend modes to texture sampler modes.
