* \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.
*/
static GLboolean
-validate_stencil_op(GLcontext *ctx, GLenum op)
+validate_stencil_op(struct gl_context *ctx, GLenum op)
{
switch (op) {
case GL_KEEP:
static GLboolean
-validate_stencil_func(GLcontext *ctx, GLenum func)
+validate_stencil_func(struct gl_context *ctx, GLenum func)
{
switch (func) {
case GL_NEVER:
* \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
* \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
* \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
* 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] ||
*
* \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;
ctx->Stencil.WriteMask[1] = ~0U;
ctx->Stencil.WriteMask[2] = ~0U;
ctx->Stencil.Clear = 0;
+ ctx->Stencil._BackFace = 1;
}