mesa: Make a Mesa core function for sRGB render encoding handling.

v2: const-qualify ctx, and add a comment about the function (recommended
    by Brian and Kenneth).

Reviewed-by: Brian Paul <brianp@vmware.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org> (v1)

1 files changed, 17 insertions, 0 deletions

diff --git a/src/mesa/main/blend.c b/src/mesa/main/blend.c
index 7413b15..0c28352 100644
--- a/src/mesa/main/blend.c
+++ b/src/mesa/main/blend.c
@@ -856,6 +856,23 @@ _mesa_update_clamp_vertex_color(struct gl_context *ctx)
    ctx->Light._ClampVertexColor = _mesa_get_clamp_vertex_color(ctx);
 }
 
+/**
+ * Returns an appropriate gl_format for color rendering based on the
+ * GL_FRAMEBUFFER_SRGB state.
+ *
+ * Some drivers implement GL_FRAMEBUFFER_SRGB using a flag on the blend state
+ * (which GL_FRAMEBUFFER_SRGB maps to reasonably), but some have to do so by
+ * overriding the format of the surface.  This is a helper for doing the
+ * surface format override variant.
+ */
+gl_format
+_mesa_get_render_format(const struct gl_context *ctx, gl_format format)
+{
+   if (ctx->Color.sRGBEnabled)
+      return format;
+   else
+      return _mesa_get_srgb_format_linear(format);
+}
 
 /**********************************************************************/
 /** \name Initialization */