mesa: add support for GL_EXT_polygon_offset_clamp

Nothing enables the extension yet, but the values are now available.
The spec calls for it to only be exposed for GL 3.3+, which is core-only
in mesa. Instead we allow any driver to enable it, including in a compat
context for any GL version.

Signed-off-by: Ilia Mirkin <[email protected]>
Reviewed-by: Glenn Kennard <[email protected]>

1 files changed, 30 insertions, 10 deletions

diff --git a/src/mesa/main/polygon.c b/src/mesa/main/polygon.c
index e3b90739d03..a1f0aa02da1 100644
--- a/src/mesa/main/polygon.c
+++ b/src/mesa/main/polygon.c
@@ -235,25 +235,33 @@ _mesa_GetPolygonStipple( GLubyte *dest )
    _mesa_GetnPolygonStippleARB(INT_MAX, dest);
 }
 
-
-void GLAPIENTRY
-_mesa_PolygonOffset( GLfloat factor, GLfloat units )
+void
+_mesa_polygon_offset_clamp(struct gl_context *ctx,
+                           GLfloat factor, GLfloat units, GLfloat clamp)
 {
-   GET_CURRENT_CONTEXT(ctx);
-
-   if (MESA_VERBOSE&VERBOSE_API)
-      _mesa_debug(ctx, "glPolygonOffset %f %f\n", factor, units);
-
    if (ctx->Polygon.OffsetFactor == factor &&
-       ctx->Polygon.OffsetUnits == units)
+       ctx->Polygon.OffsetUnits == units &&
+       ctx->Polygon.OffsetClamp == clamp)
       return;
 
    FLUSH_VERTICES(ctx, _NEW_POLYGON);
    ctx->Polygon.OffsetFactor = factor;
    ctx->Polygon.OffsetUnits = units;
+   ctx->Polygon.OffsetClamp = clamp;
 
    if (ctx->Driver.PolygonOffset)
-      ctx->Driver.PolygonOffset( ctx, factor, units );
+      ctx->Driver.PolygonOffset( ctx, factor, units, clamp );
+}
+
+void GLAPIENTRY
+_mesa_PolygonOffset( GLfloat factor, GLfloat units )
+{
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (MESA_VERBOSE&VERBOSE_API)
+      _mesa_debug(ctx, "glPolygonOffset %f %f\n", factor, units);
+
+   _mesa_polygon_offset_clamp(ctx, factor, units, 0.0);
 }
 
 
@@ -268,7 +276,18 @@ _mesa_PolygonOffsetEXT( GLfloat factor, GLfloat bias )
 void GLAPIENTRY
 _mesa_PolygonOffsetClampEXT( GLfloat factor, GLfloat units, GLfloat clamp )
 {
+   GET_CURRENT_CONTEXT(ctx);
+
+   if (!ctx->Extensions.EXT_polygon_offset_clamp) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+                  "unsupported function (glPolygonOffsetClampEXT) called");
+      return;
+   }
+
+   if (MESA_VERBOSE&VERBOSE_API)
+      _mesa_debug(ctx, "glPolygonOffsetClampEXT %f %f %f\n", factor, units, clamp);
 
+   _mesa_polygon_offset_clamp(ctx, factor, units, clamp);
 }
 
 
@@ -298,6 +317,7 @@ void _mesa_init_polygon( struct gl_context * ctx )
    ctx->Polygon.StippleFlag = GL_FALSE;
    ctx->Polygon.OffsetFactor = 0.0F;
    ctx->Polygon.OffsetUnits = 0.0F;
+   ctx->Polygon.OffsetClamp = 0.0F;
    ctx->Polygon.OffsetPoint = GL_FALSE;
    ctx->Polygon.OffsetLine = GL_FALSE;
    ctx->Polygon.OffsetFill = GL_FALSE;