X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fmesa%2Fmain%2Fstencil.c;h=93e2e97ce0c724d31cc0eaed9e2804c0c0c281d2;hb=04dca296e0a5e5ffbb8acb699e013a23ebd7b645;hp=6d6bbb2286b38b3b0fe8baa5c8096c50f0392e95;hpb=2a968113a925845331f0532a5a20d9fa1502c118;p=mesa.git

diff --git a/src/mesa/main/stencil.c b/src/mesa/main/stencil.c
index 6d6bbb2286b..93e2e97ce0c 100644
--- a/src/mesa/main/stencil.c
+++ b/src/mesa/main/stencil.c
@@ -27,6 +27,23 @@
  * \file stencil.c
  * Stencil operations.
  *
+ * Note: There's some conflict between GL_EXT_stencil_two_side and
+ * OpenGL 2.0's two-sided stencil feature.
+ *
+ * With GL_EXT_stencil_two_side, calling glStencilOp/Func/Mask() only the
+ * front OR back face state (as set by glActiveStencilFaceEXT) is set.
+ *
+ * But with OpenGL 2.0, calling glStencilOp/Func/Mask() sets BOTH the
+ * front AND back state.
+ *
+ * Also, note that GL_ATI_separate_stencil is different as well:
+ * glStencilFuncSeparateATI(GLenum frontfunc, GLenum backfunc, ...)  vs.
+ * glStencilFuncSeparate(GLenum face, GLenum func, ...).
+ *
+ * This problem is solved by keeping three sets of stencil state:
+ *  state[0] = GL_FRONT state.
+ *  state[1] = OpenGL 2.0 / GL_ATI_separate_stencil GL_BACK state.
+ *  state[2] = GL_EXT_stencil_two_side GL_BACK state.
  */
 
 
@@ -39,7 +56,7 @@
 
 
 static GLboolean
-validate_stencil_op(GLcontext *ctx, GLenum op)
+validate_stencil_op(struct gl_context *ctx, GLenum op)
 {
    switch (op) {
    case GL_KEEP:
@@ -62,7 +79,7 @@ validate_stencil_op(GLcontext *ctx, GLenum op)
 
 
 static GLboolean
-validate_stencil_func(GLcontext *ctx, GLenum func)
+validate_stencil_func(struct gl_context *ctx, GLenum func)
 {
    switch (func) {
    case GL_NEVER:
@@ -120,7 +137,7 @@ _mesa_ClearStencil( GLint s )
  * \sa glStencilFunc().
  *
  * Verifies the parameters and updates the respective values in
- * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
+ * __struct gl_contextRec::Stencil. On change flushes the vertices and notifies the
  * driver via the dd_function_table::StencilFunc callback.
  */
 void GLAPIENTRY
@@ -175,7 +192,7 @@ _mesa_StencilFuncSeparateATI( GLenum frontfunc, GLenum backfunc, GLint ref, GLui
  * \sa glStencilFunc().
  *
  * Verifies the parameters and updates the respective values in
- * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
+ * __struct gl_contextRec::Stencil. On change flushes the vertices and notifies the
  * driver via the dd_function_table::StencilFunc callback.
  */
 void GLAPIENTRY
@@ -295,7 +312,7 @@ _mesa_StencilMask( GLuint mask )
  * \sa glStencilOp().
  * 
  * Verifies the parameters and updates the respective fields in
- * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
+ * __struct gl_contextRec::Stencil. On change flushes the vertices and notifies the
  * driver via the dd_function_table::StencilOp callback.
  */
 void GLAPIENTRY
@@ -515,11 +532,15 @@ _mesa_StencilMaskSeparate(GLenum face, GLuint mask)
  * Update derived stencil state.
  */
 void
-_mesa_update_stencil(GLcontext *ctx)
+_mesa_update_stencil(struct gl_context *ctx)
 {
    const GLint face = ctx->Stencil._BackFace;
 
-   ctx->Stencil._TestTwoSide =
+   ctx->Stencil._Enabled = (ctx->Stencil.Enabled &&
+                            ctx->DrawBuffer->Visual.stencilBits > 0);
+
+    ctx->Stencil._TestTwoSide =
+       ctx->Stencil._Enabled &&
        (ctx->Stencil.Function[0] != ctx->Stencil.Function[face] ||
 	ctx->Stencil.FailFunc[0] != ctx->Stencil.FailFunc[face] ||
 	ctx->Stencil.ZPassFunc[0] != ctx->Stencil.ZPassFunc[face] ||
@@ -535,14 +556,14 @@ _mesa_update_stencil(GLcontext *ctx)
  *
  * \param ctx GL context.
  *
- * Initializes __GLcontextRec::Stencil attribute group.
+ * Initializes __struct gl_contextRec::Stencil attribute group.
  */
 void
-_mesa_init_stencil(GLcontext *ctx)
+_mesa_init_stencil(struct gl_context *ctx)
 {
    ctx->Stencil.Enabled = GL_FALSE;
    ctx->Stencil.TestTwoSide = GL_FALSE;
-   ctx->Stencil.ActiveFace = 0;  /* 0 = GL_FRONT, 1 = GL_BACK */
+   ctx->Stencil.ActiveFace = 0;  /* 0 = GL_FRONT, 2 = GL_BACK */
    ctx->Stencil.Function[0] = GL_ALWAYS;
    ctx->Stencil.Function[1] = GL_ALWAYS;
    ctx->Stencil.Function[2] = GL_ALWAYS;