core,man: Fix range and default value of WAFFLE_*_SIZE attrs

For each of the WAFFLE_*_SIZE attributes:
  - change the default value from WAFFLE_DONT_CARE(-1) to 0, and
  - change the valid range of values from [-1, +inf) to [0, +inf).

This change aligns waffle's behavior to that of GLX [1], EGL [2], and (if
I interpreted the CGL documentation correctly) CGL [3].

This fixes a bug where, if the user didn't specify the value of a size
attribute, then waffle passed WAFFLE_DONT_CARE(-1) to glXChooseFBConfig
and eglChooseConfig. Per the GLX, EGL specs, -1 is an illegal value for
size attributes.

[1] GLX 1.4 spec (2005.12.16), Table 3.4
[2] EGL 1.4 spec (2011.04.06), Table 3.4
[3] https://developer.apple.com/library/mac/documentation/graphicsimaging/reference/CGL_OpenGL/Reference/reference.html#//apple_ref/c/func/CGLChoosePixelFormat

Reported-by: Brian Paul <brian.e.paul@gmail.com>
Signed-off-by: Chad Versace <chad.versace@linux.intel.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/man/waffle_config.3.xml b/man/waffle_config.3.xml
index 402ed26..00631af 100644
--- a/man/waffle_config.3.xml
+++ b/man/waffle_config.3.xml
@@ -352,7 +352,11 @@ struct waffle_config;
         <term><constant>WAFFLE_STENCIL_SIZE</constant></term>
         <listitem>
           <para>
-            The default value for each size attribute is <constant>WAFFLE_DONT_CARE</constant>. If the requested size
+            The default value for each size attribute is <constant>0</constant>.
+
+            The range of valid values is the non-negative integers.
+
+            If the requested size
             for a channel is 0, then any surface created with the config will lack that channel. If the requested size
             for a channel is positive, then the number of bits in that channel for any surface created with the config
             will be at least the requested size.