docs: Fix the documentation for texture coordinates in snippets

The documentation for the builtin varyings for the texture coordinates
was wrongly claiming that the varyings are stored in an array. This
was changed in e55b64a9cdc9 so that each layer gets its own
independent varying.

The documentation was also referring to texture units instead of layer
numbers. The texture units are no longer publicly exposed in the
shaders and instead everything should in theory be expressed in terms
of layer numbers.

Reviewed-by: Robert Bragg <robert@linux.intel.com>

1 files changed, 15 insertions, 11 deletions

diff --git a/cogl/cogl-snippet.h b/cogl/cogl-snippet.h
index 9e83c548..5eecbfc8 100644
--- a/cogl/cogl-snippet.h
+++ b/cogl/cogl-snippet.h
@@ -165,17 +165,17 @@ COGL_BEGIN_DECLS
  *   <glossterm>attribute vec4
  *         <emphasis>cogl_tex_coord_in</emphasis></glossterm>
  *   <glossdef><para>
- *    The texture coordinate for the first texture unit. This is
- *    equivalent to #gl_MultiTexCoord0.
+ *    The texture coordinate for layer 0. This is an alternative name
+ *    for #cogl_tex_coord0_in.
  *   </para></glossdef>
  *  </glossentry>
  *  <glossentry>
  *   <glossterm>attribute vec4
  *         <emphasis>cogl_tex_coord0_in</emphasis></glossterm>
  *   <glossdef><para>
- *    The texture coordinate for the first texture unit. This is
- *    equivalent to #gl_MultiTexCoord0. There is also
- *    #cogl_tex_coord1_in and so on.
+ *    The texture coordinate for the layer 0. This is equivalent to
+ *    #gl_MultiTexCoord0. There will also be #cogl_tex_coord1_in and
+ *    so on if more layers are added to the pipeline.
  *   </para></glossdef>
  *  </glossentry>
  *  <glossentry>
@@ -219,10 +219,13 @@ COGL_BEGIN_DECLS
  *  </glossentry>
  *  <glossentry>
  *   <glossterm>varying vec4
- *         <emphasis>cogl_tex_coord_out</emphasis>[]</glossterm>
+ *         <emphasis>cogl_tex_coord0_out</emphasis></glossterm>
  *   <glossdef><para>
- *    An array of calculated texture coordinates for a vertex. This is
- *    equivalent to #gl_TexCoord.
+ *    The calculated texture coordinate for layer 0 of the pipeline.
+ *    This is equivalent to #gl_TexCoord[0]. There will also be
+ *    #cogl_tex_coord1_out and so on if more layers are added to the
+ *    pipeline. In the fragment shader, this varying is called
+ *    #cogl_tex_coord0_in.
  *   </para></glossdef>
  *  </glossentry>
  * </glosslist>
@@ -238,10 +241,11 @@ COGL_BEGIN_DECLS
  *  </glossentry>
  *  <glossentry>
  *   <glossterm>varying vec4
- *              <emphasis>cogl_tex_coord_in</emphasis>[]</glossterm>
+ *              <emphasis>cogl_tex_coord0_in</emphasis></glossterm>
  *   <glossdef><para>
- *    An array of calculated texture coordinates for a vertex. This is
- *    equivalent to #gl_TexCoord.
+ *    The texture coordinate for layer 0. This is equivalent to
+ *    #gl_TexCoord[0]. There will also be #cogl_tex_coord1_in and so
+ *    on if more layers are added to the pipeline.
  *   </para></glossdef>
  *  </glossentry>
  *  <glossentry>