diff options
Diffstat (limited to 'debian/patches/94-gl-Add-a-first-bit-of-general-documentation-on-cairo.patch')
| -rw-r--r-- | debian/patches/94-gl-Add-a-first-bit-of-general-documentation-on-cairo.patch | 56 |
1 files changed, 56 insertions, 0 deletions
diff --git a/debian/patches/94-gl-Add-a-first-bit-of-general-documentation-on-cairo.patch b/debian/patches/94-gl-Add-a-first-bit-of-general-documentation-on-cairo.patch new file mode 100644 index 0000000..3c48cad --- /dev/null +++ b/debian/patches/94-gl-Add-a-first-bit-of-general-documentation-on-cairo.patch @@ -0,0 +1,56 @@ +From 0bcb69c16d1146c22c3b87be1e19492a5d763257 Mon Sep 17 00:00:00 2001 +From: Eric Anholt <eric@anholt.net> +Date: Sun, 30 Jan 2011 23:41:39 -0800 +Subject: [PATCH 14/16] gl: Add a first bit of general documentation on + cairo-gl usage. + +Since its inception, cairo-gl has been plagued by the "how am I really +supposed to use it?" problem. This lays down my expectations for how +cairo-gl will interact with other usage of the GL API. +(cherry picked from commit 2e67809be0a2febd52c75948fabd7ac81227e5e3) + +Signed-off-by: Cyril Brulebois <kibi@debian.org> +--- + src/cairo-gl.h | 26 ++++++++++++++++++++++++++ + 1 files changed, 26 insertions(+), 0 deletions(-) + +diff --git a/src/cairo-gl.h b/src/cairo-gl.h +index 131d114..9efde43 100644 +--- a/src/cairo-gl.h ++++ b/src/cairo-gl.h +@@ -31,6 +31,32 @@ + * The Initial Developer of the Original Code is Eric Anholt. + */ + ++/** ++ * @file cairo-gl.h ++ * ++ * The cairo-gl backend provides an implementation of possibly ++ * hardware-accelerated cairo rendering by targeting the OpenGL API. ++ * The goal of the cairo-gl backend is to provide better performance ++ * with equal functionality to cairo-image where possible. It does ++ * not directly provide for applying additional OpenGL effects to ++ * cairo surfaces. ++ * ++ * Cairo-gl allows interoperability with other GL rendering through GL ++ * context sharing. Cairo-gl surfaces are created in reference to a ++ * cairo_device_t, which represents an GL context created by the user. ++ * When that GL context is created with its sharePtr set to another ++ * context (or vice versa), its objects (textures backing cairo-gl ++ * surfaces) can be accessed in the other OpenGL context. This allows ++ * cairo-gl to maintain its drawing state in one context while the ++ * user's 3D rendering occurs in the user's other context. ++ * ++ * However, as only one context can be current to a thread at a time, ++ * cairo-gl may make its context current to the thread on any cairo ++ * call which interacts with a cairo-gl surface or the cairo-gl ++ * device. As a result, the user must make their own context current ++ * between any cairo calls and their own OpenGL rendering. ++ */ ++ + #ifndef CAIRO_GL_H + #define CAIRO_GL_H + +-- +1.7.5.4 + |