src/parsec/disk-image/parsec/parsec-benchmark/pkgs/libs/mesa/src/src/mesa/main/stencil.c - public/gem5-resources - Git at Google

 /*
  * Mesa 3-D graphics library
  * Version:  7.1
  *
  * Copyright (C) 1999-2007  Brian Paul   All Rights Reserved.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a
  * copy of this software and associated documentation files (the "Software"),
  * to deal in the Software without restriction, including without limitation
  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  * and/or sell copies of the Software, and to permit persons to whom the
  * Software is furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included
  * in all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
  * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  * BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
  * AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  */


 /**
  * \file stencil.c
  * Stencil operations.
  *
  * Note: There's an incompatibility 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.
  *
  * So either we advertise the GL_EXT_stencil_two_side extension, or OpenGL
  * 2.0, but not both.
  *
  * Also, note that GL_ATI_separate_stencil is different as well:
  * glStencilFuncSeparateATI(GLenum frontfunc, GLenum backfunc, ...)  vs.
  * glStencilFuncSeparate(GLenum face, GLenum func, ...).
  */


 #include "glheader.h"
 #include "imports.h"
 #include "context.h"
 #include "macros.h"
 #include "stencil.h"
 #include "mtypes.h"


 static GLboolean
 validate_stencil_op(GLcontext *ctx, GLenum op)
 {
    switch (op) {
    case GL_KEEP:
    case GL_ZERO:
    case GL_REPLACE:
    case GL_INCR:
    case GL_DECR:
    case GL_INVERT:
       return GL_TRUE;
    case GL_INCR_WRAP_EXT:
    case GL_DECR_WRAP_EXT:
       if (ctx->Extensions.EXT_stencil_wrap) {
          return GL_TRUE;
       }
       /* FALL-THROUGH */
    default:
       return GL_FALSE;
    }
 }


 static GLboolean
 validate_stencil_func(GLcontext *ctx, GLenum func)
 {
    switch (func) {
    case GL_NEVER:
    case GL_LESS:
    case GL_LEQUAL:
    case GL_GREATER:
    case GL_GEQUAL:
    case GL_EQUAL:
    case GL_NOTEQUAL:
    case GL_ALWAYS:
       return GL_TRUE;
    default:
       return GL_FALSE;
    }
 }


 /**
  * Set the clear value for the stencil buffer.
  *
  * \param s clear value.
  *
  * \sa glClearStencil().
  *
  * Updates gl_stencil_attrib::Clear. On change
  * flushes the vertices and notifies the driver via
  * the dd_function_table::ClearStencil callback.
  */
 void GLAPIENTRY
 _mesa_ClearStencil( GLint s )
 {
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (ctx->Stencil.Clear == (GLuint) s)
       return;

    FLUSH_VERTICES(ctx, _NEW_STENCIL);
    ctx->Stencil.Clear = (GLuint) s;

    if (ctx->Driver.ClearStencil) {
       ctx->Driver.ClearStencil( ctx, s );
    }
 }


 /**
  * Set the function and reference value for stencil testing.
  *
  * \param frontfunc front test function.
  * \param backfunc back test function.
  * \param ref front and back reference value.
  * \param mask front and back bitmask.
  *
  * \sa glStencilFunc().
  *
  * Verifies the parameters and updates the respective values in
  * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
  * driver via the dd_function_table::StencilFunc callback.
  */
 void GLAPIENTRY
 _mesa_StencilFuncSeparateATI( GLenum frontfunc, GLenum backfunc, GLint ref, GLuint mask )
 {
    GET_CURRENT_CONTEXT(ctx);
    const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (!validate_stencil_func(ctx, frontfunc)) {
       _mesa_error(ctx, GL_INVALID_ENUM,
                   "glStencilFuncSeparateATI(frontfunc)");
       return;
    }
    if (!validate_stencil_func(ctx, backfunc)) {
       _mesa_error(ctx, GL_INVALID_ENUM,
                   "glStencilFuncSeparateATI(backfunc)");
       return;
    }

    ref = CLAMP( ref, 0, stencilMax );

    /* set both front and back state */
    if (ctx->Stencil.Function[0] == frontfunc &&
        ctx->Stencil.Function[1] == backfunc &&
        ctx->Stencil.ValueMask[0] == mask &&
        ctx->Stencil.ValueMask[1] == mask &&
        ctx->Stencil.Ref[0] == ref &&
        ctx->Stencil.Ref[1] == ref)
       return;
    FLUSH_VERTICES(ctx, _NEW_STENCIL);
    ctx->Stencil.Function[0]  = frontfunc;
    ctx->Stencil.Function[1]  = backfunc;
    ctx->Stencil.Ref[0]       = ctx->Stencil.Ref[1]       = ref;
    ctx->Stencil.ValueMask[0] = ctx->Stencil.ValueMask[1] = mask;
    if (ctx->Driver.StencilFuncSeparate) {
       ctx->Driver.StencilFuncSeparate(ctx, GL_FRONT,
                                       frontfunc, ref, mask);
       ctx->Driver.StencilFuncSeparate(ctx, GL_BACK,
                                       backfunc, ref, mask);
    }
 }


 /**
  * Set the function and reference value for stencil testing.
  *
  * \param func test function.
  * \param ref reference value.
  * \param mask bitmask.
  *
  * \sa glStencilFunc().
  *
  * Verifies the parameters and updates the respective values in
  * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
  * driver via the dd_function_table::StencilFunc callback.
  */
 void GLAPIENTRY
 _mesa_StencilFunc( GLenum func, GLint ref, GLuint mask )
 {
    GET_CURRENT_CONTEXT(ctx);
    const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (!validate_stencil_func(ctx, func)) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFunc(func)");
       return;
    }

    ref = CLAMP( ref, 0, stencilMax );

    if (ctx->Extensions.EXT_stencil_two_side) {
       /* only set active face state */
       const GLint face = ctx->Stencil.ActiveFace;
       if (ctx->Stencil.Function[face] == func &&
           ctx->Stencil.ValueMask[face] == mask &&
           ctx->Stencil.Ref[face] == ref)
          return;
       FLUSH_VERTICES(ctx, _NEW_STENCIL);
       ctx->Stencil.Function[face] = func;
       ctx->Stencil.Ref[face] = ref;
       ctx->Stencil.ValueMask[face] = mask;
       if (ctx->Driver.StencilFuncSeparate) {
          ctx->Driver.StencilFuncSeparate(ctx, face ? GL_BACK : GL_FRONT,
                                          func, ref, mask);
       }
    }
    else {
       /* set both front and back state */
       if (ctx->Stencil.Function[0] == func &&
           ctx->Stencil.Function[1] == func &&
           ctx->Stencil.ValueMask[0] == mask &&
           ctx->Stencil.ValueMask[1] == mask &&
           ctx->Stencil.Ref[0] == ref &&
           ctx->Stencil.Ref[1] == ref)
          return;
       FLUSH_VERTICES(ctx, _NEW_STENCIL);
       ctx->Stencil.Function[0]  = ctx->Stencil.Function[1]  = func;
       ctx->Stencil.Ref[0]       = ctx->Stencil.Ref[1]       = ref;
       ctx->Stencil.ValueMask[0] = ctx->Stencil.ValueMask[1] = mask;
       if (ctx->Driver.StencilFuncSeparate) {
          ctx->Driver.StencilFuncSeparate(ctx, GL_FRONT_AND_BACK,
                                          func, ref, mask);
       }
    }
 }


 /**
  * Set the stencil writing mask.
  *
  * \param mask bit-mask to enable/disable writing of individual bits in the
  * stencil planes.
  *
  * \sa glStencilMask().
  *
  * Updates gl_stencil_attrib::WriteMask. On change flushes the vertices and
  * notifies the driver via the dd_function_table::StencilMask callback.
  */
 void GLAPIENTRY
 _mesa_StencilMask( GLuint mask )
 {
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (ctx->Extensions.EXT_stencil_two_side) {
       /* only set active face state */
       const GLint face = ctx->Stencil.ActiveFace;
       if (ctx->Stencil.WriteMask[face] == mask)
          return;
       FLUSH_VERTICES(ctx, _NEW_STENCIL);
       ctx->Stencil.WriteMask[face] = mask;
       if (ctx->Driver.StencilMaskSeparate) {
          ctx->Driver.StencilMaskSeparate(ctx, face ? GL_BACK : GL_FRONT, mask);
       }
    }
    else {
       /* set both front and back state */
       if (ctx->Stencil.WriteMask[0] == mask &&
           ctx->Stencil.WriteMask[1] == mask)
          return;
       FLUSH_VERTICES(ctx, _NEW_STENCIL);
       ctx->Stencil.WriteMask[0] = ctx->Stencil.WriteMask[1] = mask;
       if (ctx->Driver.StencilMaskSeparate) {
          ctx->Driver.StencilMaskSeparate(ctx, GL_FRONT_AND_BACK, mask);
       }
    }
 }


 /**
  * Set the stencil test actions.
  *
  * \param fail action to take when stencil test fails.
  * \param zfail action to take when stencil test passes, but depth test fails.
  * \param zpass action to take when stencil test passes and the depth test
  * passes (or depth testing is not enabled).
  *
  * \sa glStencilOp().
  *
  * Verifies the parameters and updates the respective fields in
  * __GLcontextRec::Stencil. On change flushes the vertices and notifies the
  * driver via the dd_function_table::StencilOp callback.
  */
 void GLAPIENTRY
 _mesa_StencilOp(GLenum fail, GLenum zfail, GLenum zpass)
 {
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (!validate_stencil_op(ctx, fail)) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp(sfail)");
       return;
    }
    if (!validate_stencil_op(ctx, zfail)) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp(zfail)");
       return;
    }
    if (!validate_stencil_op(ctx, zpass)) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp(zpass)");
       return;
    }

    if (ctx->Extensions.EXT_stencil_two_side) {
       /* only set active face state */
       const GLint face = ctx->Stencil.ActiveFace;
       if (ctx->Stencil.ZFailFunc[face] == zfail &&
           ctx->Stencil.ZPassFunc[face] == zpass &&
           ctx->Stencil.FailFunc[face] == fail)
          return;
       FLUSH_VERTICES(ctx, _NEW_STENCIL);
       ctx->Stencil.ZFailFunc[face] = zfail;
       ctx->Stencil.ZPassFunc[face] = zpass;
       ctx->Stencil.FailFunc[face] = fail;
       if (ctx->Driver.StencilOpSeparate) {
          ctx->Driver.StencilOpSeparate(ctx, face ? GL_BACK : GL_FRONT,
                                        fail, zfail, zpass);
       }
    }
    else {
       /* set both front and back state */
       if (ctx->Stencil.ZFailFunc[0] == zfail &&
           ctx->Stencil.ZFailFunc[1] == zfail &&
           ctx->Stencil.ZPassFunc[0] == zpass &&
           ctx->Stencil.ZPassFunc[1] == zpass &&
           ctx->Stencil.FailFunc[0] == fail &&
           ctx->Stencil.FailFunc[1] == fail)
          return;
       FLUSH_VERTICES(ctx, _NEW_STENCIL);
       ctx->Stencil.ZFailFunc[0] = ctx->Stencil.ZFailFunc[1] = zfail;
       ctx->Stencil.ZPassFunc[0] = ctx->Stencil.ZPassFunc[1] = zpass;
       ctx->Stencil.FailFunc[0]  = ctx->Stencil.FailFunc[1]  = fail;
       if (ctx->Driver.StencilOpSeparate) {
          ctx->Driver.StencilOpSeparate(ctx, GL_FRONT_AND_BACK,
                                        fail, zfail, zpass);
       }
    }
 }


 #if _HAVE_FULL_GL
 /* GL_EXT_stencil_two_side */
 void GLAPIENTRY
 _mesa_ActiveStencilFaceEXT(GLenum face)
 {
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (!ctx->Extensions.EXT_stencil_two_side) {
       _mesa_error(ctx, GL_INVALID_OPERATION, "glActiveStencilFaceEXT");
       return;
    }

    if (face == GL_FRONT || face == GL_BACK) {
       FLUSH_VERTICES(ctx, _NEW_STENCIL);
       ctx->Stencil.ActiveFace = (face == GL_FRONT) ? 0 : 1;
    }
    else {
       _mesa_error(ctx, GL_INVALID_ENUM, "glActiveStencilFaceEXT(face)");
    }
 }
 #endif


 /**
  * OpenGL 2.0 function.
  * \todo Make StencilOp() call this function.  And eventually remove the
  * ctx->Driver.StencilOp function and use ctx->Driver.StencilOpSeparate
  * instead.
  */
 void GLAPIENTRY
 _mesa_StencilOpSeparate(GLenum face, GLenum sfail, GLenum zfail, GLenum zpass)
 {
    GLboolean set = GL_FALSE;
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (!validate_stencil_op(ctx, sfail)) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(sfail)");
       return;
    }
    if (!validate_stencil_op(ctx, zfail)) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zfail)");
       return;
    }
    if (!validate_stencil_op(ctx, zpass)) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zpass)");
       return;
    }
    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(face)");
       return;
    }

    if (face != GL_BACK) {
       /* set front */
       if (ctx->Stencil.ZFailFunc[0] != zfail ||
           ctx->Stencil.ZPassFunc[0] != zpass ||
           ctx->Stencil.FailFunc[0] != sfail){
          FLUSH_VERTICES(ctx, _NEW_STENCIL);
          ctx->Stencil.ZFailFunc[0] = zfail;
          ctx->Stencil.ZPassFunc[0] = zpass;
          ctx->Stencil.FailFunc[0] = sfail;
          set = GL_TRUE;
       }
    }
    if (face != GL_FRONT) {
       /* set back */
       if (ctx->Stencil.ZFailFunc[1] != zfail ||
           ctx->Stencil.ZPassFunc[1] != zpass ||
           ctx->Stencil.FailFunc[1] != sfail) {
          FLUSH_VERTICES(ctx, _NEW_STENCIL);
          ctx->Stencil.ZFailFunc[1] = zfail;
          ctx->Stencil.ZPassFunc[1] = zpass;
          ctx->Stencil.FailFunc[1] = sfail;
          set = GL_TRUE;
       }
    }
    if (set && ctx->Driver.StencilOpSeparate) {
       ctx->Driver.StencilOpSeparate(ctx, face, sfail, zfail, zpass);
    }
 }


 /* OpenGL 2.0 */
 void GLAPIENTRY
 _mesa_StencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask)
 {
    GET_CURRENT_CONTEXT(ctx);
    const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(face)");
       return;
    }
    if (!validate_stencil_func(ctx, func)) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(func)");
       return;
    }

    ref = CLAMP(ref, 0, stencilMax);

    FLUSH_VERTICES(ctx, _NEW_STENCIL);

    if (face != GL_BACK) {
       /* set front */
       ctx->Stencil.Function[0] = func;
       ctx->Stencil.Ref[0] = ref;
       ctx->Stencil.ValueMask[0] = mask;
    }
    if (face != GL_FRONT) {
       /* set back */
       ctx->Stencil.Function[1] = func;
       ctx->Stencil.Ref[1] = ref;
       ctx->Stencil.ValueMask[1] = mask;
    }
    if (ctx->Driver.StencilFuncSeparate) {
       ctx->Driver.StencilFuncSeparate(ctx, face, func, ref, mask);
    }
 }


 /* OpenGL 2.0 */
 void GLAPIENTRY
 _mesa_StencilMaskSeparate(GLenum face, GLuint mask)
 {
    GET_CURRENT_CONTEXT(ctx);
    ASSERT_OUTSIDE_BEGIN_END(ctx);

    if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
       _mesa_error(ctx, GL_INVALID_ENUM, "glStencilaMaskSeparate(face)");
       return;
    }

    FLUSH_VERTICES(ctx, _NEW_STENCIL);

    if (face != GL_BACK) {
       ctx->Stencil.WriteMask[0] = mask;
    }
    if (face != GL_FRONT) {
       ctx->Stencil.WriteMask[1] = mask;
    }
    if (ctx->Driver.StencilMaskSeparate) {
       ctx->Driver.StencilMaskSeparate(ctx, face, mask);
    }
 }


 /**
  * Update derived stencil state.
  */
 void
 _mesa_update_stencil(GLcontext *ctx)
 {
    if (ctx->Extensions.EXT_stencil_two_side) {
       ctx->Stencil._TestTwoSide = ctx->Stencil.TestTwoSide;
    }
    else {
       ctx->Stencil._TestTwoSide =
          (ctx->Stencil.Function[0] != ctx->Stencil.Function[1] ||
           ctx->Stencil.FailFunc[0] != ctx->Stencil.FailFunc[1] ||
           ctx->Stencil.ZPassFunc[0] != ctx->Stencil.ZPassFunc[1] ||
           ctx->Stencil.ZFailFunc[0] != ctx->Stencil.ZFailFunc[1] ||
           ctx->Stencil.Ref[0] != ctx->Stencil.Ref[1] ||
           ctx->Stencil.ValueMask[0] != ctx->Stencil.ValueMask[1] ||
           ctx->Stencil.WriteMask[0] != ctx->Stencil.WriteMask[1]);
    }
 }


 /**
  * Initialize the context stipple state.
  *
  * \param ctx GL context.
  *
  * Initializes __GLcontextRec::Stencil attribute group.
  */
 void
 _mesa_init_stencil(GLcontext *ctx)
 {
    ctx->Stencil.Enabled = GL_FALSE;
    ctx->Stencil.TestTwoSide = GL_FALSE;
    ctx->Stencil.ActiveFace = 0;  /* 0 = GL_FRONT, 1 = GL_BACK */
    ctx->Stencil.Function[0] = GL_ALWAYS;
    ctx->Stencil.Function[1] = GL_ALWAYS;
    ctx->Stencil.FailFunc[0] = GL_KEEP;
    ctx->Stencil.FailFunc[1] = GL_KEEP;
    ctx->Stencil.ZPassFunc[0] = GL_KEEP;
    ctx->Stencil.ZPassFunc[1] = GL_KEEP;
    ctx->Stencil.ZFailFunc[0] = GL_KEEP;
    ctx->Stencil.ZFailFunc[1] = GL_KEEP;
    ctx->Stencil.Ref[0] = 0;
    ctx->Stencil.Ref[1] = 0;
    ctx->Stencil.ValueMask[0] = ~0U;
    ctx->Stencil.ValueMask[1] = ~0U;
    ctx->Stencil.WriteMask[0] = ~0U;
    ctx->Stencil.WriteMask[1] = ~0U;
    ctx->Stencil.Clear = 0;
 }
	/*
	* Mesa 3-D graphics library
	* Version: 7.1
	*
	* Copyright (C) 1999-2007 Brian Paul All Rights Reserved.
	*
	* Permission is hereby granted, free of charge, to any person obtaining a
	* copy of this software and associated documentation files (the "Software"),
	* to deal in the Software without restriction, including without limitation
	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	* and/or sell copies of the Software, and to permit persons to whom the
	* Software is furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included
	* in all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
	* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* BRIAN PAUL BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN
	* AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
	* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
	*/


	/**
	* \file stencil.c
	* Stencil operations.
	*
	* Note: There's an incompatibility 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.
	*
	* So either we advertise the GL_EXT_stencil_two_side extension, or OpenGL
	* 2.0, but not both.
	*
	* Also, note that GL_ATI_separate_stencil is different as well:
	* glStencilFuncSeparateATI(GLenum frontfunc, GLenum backfunc, ...) vs.
	* glStencilFuncSeparate(GLenum face, GLenum func, ...).
	*/


	#include "glheader.h"
	#include "imports.h"
	#include "context.h"
	#include "macros.h"
	#include "stencil.h"
	#include "mtypes.h"


	static GLboolean
	validate_stencil_op(GLcontext *ctx, GLenum op)
	{
	switch (op) {
	case GL_KEEP:
	case GL_ZERO:
	case GL_REPLACE:
	case GL_INCR:
	case GL_DECR:
	case GL_INVERT:
	return GL_TRUE;
	case GL_INCR_WRAP_EXT:
	case GL_DECR_WRAP_EXT:
	if (ctx->Extensions.EXT_stencil_wrap) {
	return GL_TRUE;
	}
	/* FALL-THROUGH */
	default:
	return GL_FALSE;
	}
	}


	static GLboolean
	validate_stencil_func(GLcontext *ctx, GLenum func)
	{
	switch (func) {
	case GL_NEVER:
	case GL_LESS:
	case GL_LEQUAL:
	case GL_GREATER:
	case GL_GEQUAL:
	case GL_EQUAL:
	case GL_NOTEQUAL:
	case GL_ALWAYS:
	return GL_TRUE;
	default:
	return GL_FALSE;
	}
	}


	/**
	* Set the clear value for the stencil buffer.
	*
	* \param s clear value.
	*
	* \sa glClearStencil().
	*
	* Updates gl_stencil_attrib::Clear. On change
	* flushes the vertices and notifies the driver via
	* the dd_function_table::ClearStencil callback.
	*/
	void GLAPIENTRY
	_mesa_ClearStencil( GLint s )
	{
	GET_CURRENT_CONTEXT(ctx);
	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (ctx->Stencil.Clear == (GLuint) s)
	return;

	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.Clear = (GLuint) s;

	if (ctx->Driver.ClearStencil) {
	ctx->Driver.ClearStencil( ctx, s );
	}
	}


	/**
	* Set the function and reference value for stencil testing.
	*
	* \param frontfunc front test function.
	* \param backfunc back test function.
	* \param ref front and back reference value.
	* \param mask front and back bitmask.
	*
	* \sa glStencilFunc().
	*
	* Verifies the parameters and updates the respective values in
	* __GLcontextRec::Stencil. On change flushes the vertices and notifies the
	* driver via the dd_function_table::StencilFunc callback.
	*/
	void GLAPIENTRY
	_mesa_StencilFuncSeparateATI( GLenum frontfunc, GLenum backfunc, GLint ref, GLuint mask )
	{
	GET_CURRENT_CONTEXT(ctx);
	const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (!validate_stencil_func(ctx, frontfunc)) {
	_mesa_error(ctx, GL_INVALID_ENUM,
	"glStencilFuncSeparateATI(frontfunc)");
	return;
	}
	if (!validate_stencil_func(ctx, backfunc)) {
	_mesa_error(ctx, GL_INVALID_ENUM,
	"glStencilFuncSeparateATI(backfunc)");
	return;
	}

	ref = CLAMP( ref, 0, stencilMax );

	/* set both front and back state */
	if (ctx->Stencil.Function[0] == frontfunc &&
	ctx->Stencil.Function[1] == backfunc &&
	ctx->Stencil.ValueMask[0] == mask &&
	ctx->Stencil.ValueMask[1] == mask &&
	ctx->Stencil.Ref[0] == ref &&
	ctx->Stencil.Ref[1] == ref)
	return;
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.Function[0] = frontfunc;
	ctx->Stencil.Function[1] = backfunc;
	ctx->Stencil.Ref[0] = ctx->Stencil.Ref[1] = ref;
	ctx->Stencil.ValueMask[0] = ctx->Stencil.ValueMask[1] = mask;
	if (ctx->Driver.StencilFuncSeparate) {
	ctx->Driver.StencilFuncSeparate(ctx, GL_FRONT,
	frontfunc, ref, mask);
	ctx->Driver.StencilFuncSeparate(ctx, GL_BACK,
	backfunc, ref, mask);
	}
	}


	/**
	* Set the function and reference value for stencil testing.
	*
	* \param func test function.
	* \param ref reference value.
	* \param mask bitmask.
	*
	* \sa glStencilFunc().
	*
	* Verifies the parameters and updates the respective values in
	* __GLcontextRec::Stencil. On change flushes the vertices and notifies the
	* driver via the dd_function_table::StencilFunc callback.
	*/
	void GLAPIENTRY
	_mesa_StencilFunc( GLenum func, GLint ref, GLuint mask )
	{
	GET_CURRENT_CONTEXT(ctx);
	const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (!validate_stencil_func(ctx, func)) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilFunc(func)");
	return;
	}

	ref = CLAMP( ref, 0, stencilMax );

	if (ctx->Extensions.EXT_stencil_two_side) {
	/* only set active face state */
	const GLint face = ctx->Stencil.ActiveFace;
	if (ctx->Stencil.Function[face] == func &&
	ctx->Stencil.ValueMask[face] == mask &&
	ctx->Stencil.Ref[face] == ref)
	return;
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.Function[face] = func;
	ctx->Stencil.Ref[face] = ref;
	ctx->Stencil.ValueMask[face] = mask;
	if (ctx->Driver.StencilFuncSeparate) {
	ctx->Driver.StencilFuncSeparate(ctx, face ? GL_BACK : GL_FRONT,
	func, ref, mask);
	}
	}
	else {
	/* set both front and back state */
	if (ctx->Stencil.Function[0] == func &&
	ctx->Stencil.Function[1] == func &&
	ctx->Stencil.ValueMask[0] == mask &&
	ctx->Stencil.ValueMask[1] == mask &&
	ctx->Stencil.Ref[0] == ref &&
	ctx->Stencil.Ref[1] == ref)
	return;
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.Function[0] = ctx->Stencil.Function[1] = func;
	ctx->Stencil.Ref[0] = ctx->Stencil.Ref[1] = ref;
	ctx->Stencil.ValueMask[0] = ctx->Stencil.ValueMask[1] = mask;
	if (ctx->Driver.StencilFuncSeparate) {
	ctx->Driver.StencilFuncSeparate(ctx, GL_FRONT_AND_BACK,
	func, ref, mask);
	}
	}
	}


	/**
	* Set the stencil writing mask.
	*
	* \param mask bit-mask to enable/disable writing of individual bits in the
	* stencil planes.
	*
	* \sa glStencilMask().
	*
	* Updates gl_stencil_attrib::WriteMask. On change flushes the vertices and
	* notifies the driver via the dd_function_table::StencilMask callback.
	*/
	void GLAPIENTRY
	_mesa_StencilMask( GLuint mask )
	{
	GET_CURRENT_CONTEXT(ctx);
	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (ctx->Extensions.EXT_stencil_two_side) {
	/* only set active face state */
	const GLint face = ctx->Stencil.ActiveFace;
	if (ctx->Stencil.WriteMask[face] == mask)
	return;
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.WriteMask[face] = mask;
	if (ctx->Driver.StencilMaskSeparate) {
	ctx->Driver.StencilMaskSeparate(ctx, face ? GL_BACK : GL_FRONT, mask);
	}
	}
	else {
	/* set both front and back state */
	if (ctx->Stencil.WriteMask[0] == mask &&
	ctx->Stencil.WriteMask[1] == mask)
	return;
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.WriteMask[0] = ctx->Stencil.WriteMask[1] = mask;
	if (ctx->Driver.StencilMaskSeparate) {
	ctx->Driver.StencilMaskSeparate(ctx, GL_FRONT_AND_BACK, mask);
	}
	}
	}


	/**
	* Set the stencil test actions.
	*
	* \param fail action to take when stencil test fails.
	* \param zfail action to take when stencil test passes, but depth test fails.
	* \param zpass action to take when stencil test passes and the depth test
	* passes (or depth testing is not enabled).
	*
	* \sa glStencilOp().
	*
	* Verifies the parameters and updates the respective fields in
	* __GLcontextRec::Stencil. On change flushes the vertices and notifies the
	* driver via the dd_function_table::StencilOp callback.
	*/
	void GLAPIENTRY
	_mesa_StencilOp(GLenum fail, GLenum zfail, GLenum zpass)
	{
	GET_CURRENT_CONTEXT(ctx);
	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (!validate_stencil_op(ctx, fail)) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp(sfail)");
	return;
	}
	if (!validate_stencil_op(ctx, zfail)) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp(zfail)");
	return;
	}
	if (!validate_stencil_op(ctx, zpass)) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilOp(zpass)");
	return;
	}

	if (ctx->Extensions.EXT_stencil_two_side) {
	/* only set active face state */
	const GLint face = ctx->Stencil.ActiveFace;
	if (ctx->Stencil.ZFailFunc[face] == zfail &&
	ctx->Stencil.ZPassFunc[face] == zpass &&
	ctx->Stencil.FailFunc[face] == fail)
	return;
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.ZFailFunc[face] = zfail;
	ctx->Stencil.ZPassFunc[face] = zpass;
	ctx->Stencil.FailFunc[face] = fail;
	if (ctx->Driver.StencilOpSeparate) {
	ctx->Driver.StencilOpSeparate(ctx, face ? GL_BACK : GL_FRONT,
	fail, zfail, zpass);
	}
	}
	else {
	/* set both front and back state */
	if (ctx->Stencil.ZFailFunc[0] == zfail &&
	ctx->Stencil.ZFailFunc[1] == zfail &&
	ctx->Stencil.ZPassFunc[0] == zpass &&
	ctx->Stencil.ZPassFunc[1] == zpass &&
	ctx->Stencil.FailFunc[0] == fail &&
	ctx->Stencil.FailFunc[1] == fail)
	return;
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.ZFailFunc[0] = ctx->Stencil.ZFailFunc[1] = zfail;
	ctx->Stencil.ZPassFunc[0] = ctx->Stencil.ZPassFunc[1] = zpass;
	ctx->Stencil.FailFunc[0] = ctx->Stencil.FailFunc[1] = fail;
	if (ctx->Driver.StencilOpSeparate) {
	ctx->Driver.StencilOpSeparate(ctx, GL_FRONT_AND_BACK,
	fail, zfail, zpass);
	}
	}
	}



	#if _HAVE_FULL_GL
	/* GL_EXT_stencil_two_side */
	void GLAPIENTRY
	_mesa_ActiveStencilFaceEXT(GLenum face)
	{
	GET_CURRENT_CONTEXT(ctx);
	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (!ctx->Extensions.EXT_stencil_two_side) {
	_mesa_error(ctx, GL_INVALID_OPERATION, "glActiveStencilFaceEXT");
	return;
	}

	if (face == GL_FRONT \|\| face == GL_BACK) {
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.ActiveFace = (face == GL_FRONT) ? 0 : 1;
	}
	else {
	_mesa_error(ctx, GL_INVALID_ENUM, "glActiveStencilFaceEXT(face)");
	}
	}
	#endif



	/**
	* OpenGL 2.0 function.
	* \todo Make StencilOp() call this function. And eventually remove the
	* ctx->Driver.StencilOp function and use ctx->Driver.StencilOpSeparate
	* instead.
	*/
	void GLAPIENTRY
	_mesa_StencilOpSeparate(GLenum face, GLenum sfail, GLenum zfail, GLenum zpass)
	{
	GLboolean set = GL_FALSE;
	GET_CURRENT_CONTEXT(ctx);
	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (!validate_stencil_op(ctx, sfail)) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(sfail)");
	return;
	}
	if (!validate_stencil_op(ctx, zfail)) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zfail)");
	return;
	}
	if (!validate_stencil_op(ctx, zpass)) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(zpass)");
	return;
	}
	if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilOpSeparate(face)");
	return;
	}

	if (face != GL_BACK) {
	/* set front */
	if (ctx->Stencil.ZFailFunc[0] != zfail \|\|
	ctx->Stencil.ZPassFunc[0] != zpass \|\|
	ctx->Stencil.FailFunc[0] != sfail){
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.ZFailFunc[0] = zfail;
	ctx->Stencil.ZPassFunc[0] = zpass;
	ctx->Stencil.FailFunc[0] = sfail;
	set = GL_TRUE;
	}
	}
	if (face != GL_FRONT) {
	/* set back */
	if (ctx->Stencil.ZFailFunc[1] != zfail \|\|
	ctx->Stencil.ZPassFunc[1] != zpass \|\|
	ctx->Stencil.FailFunc[1] != sfail) {
	FLUSH_VERTICES(ctx, _NEW_STENCIL);
	ctx->Stencil.ZFailFunc[1] = zfail;
	ctx->Stencil.ZPassFunc[1] = zpass;
	ctx->Stencil.FailFunc[1] = sfail;
	set = GL_TRUE;
	}
	}
	if (set && ctx->Driver.StencilOpSeparate) {
	ctx->Driver.StencilOpSeparate(ctx, face, sfail, zfail, zpass);
	}
	}


	/* OpenGL 2.0 */
	void GLAPIENTRY
	_mesa_StencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask)
	{
	GET_CURRENT_CONTEXT(ctx);
	const GLint stencilMax = (1 << ctx->DrawBuffer->Visual.stencilBits) - 1;
	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(face)");
	return;
	}
	if (!validate_stencil_func(ctx, func)) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilFuncSeparate(func)");
	return;
	}

	ref = CLAMP(ref, 0, stencilMax);

	FLUSH_VERTICES(ctx, _NEW_STENCIL);

	if (face != GL_BACK) {
	/* set front */
	ctx->Stencil.Function[0] = func;
	ctx->Stencil.Ref[0] = ref;
	ctx->Stencil.ValueMask[0] = mask;
	}
	if (face != GL_FRONT) {
	/* set back */
	ctx->Stencil.Function[1] = func;
	ctx->Stencil.Ref[1] = ref;
	ctx->Stencil.ValueMask[1] = mask;
	}
	if (ctx->Driver.StencilFuncSeparate) {
	ctx->Driver.StencilFuncSeparate(ctx, face, func, ref, mask);
	}
	}


	/* OpenGL 2.0 */
	void GLAPIENTRY
	_mesa_StencilMaskSeparate(GLenum face, GLuint mask)
	{
	GET_CURRENT_CONTEXT(ctx);
	ASSERT_OUTSIDE_BEGIN_END(ctx);

	if (face != GL_FRONT && face != GL_BACK && face != GL_FRONT_AND_BACK) {
	_mesa_error(ctx, GL_INVALID_ENUM, "glStencilaMaskSeparate(face)");
	return;
	}

	FLUSH_VERTICES(ctx, _NEW_STENCIL);

	if (face != GL_BACK) {
	ctx->Stencil.WriteMask[0] = mask;
	}
	if (face != GL_FRONT) {
	ctx->Stencil.WriteMask[1] = mask;
	}
	if (ctx->Driver.StencilMaskSeparate) {
	ctx->Driver.StencilMaskSeparate(ctx, face, mask);
	}
	}


	/**
	* Update derived stencil state.
	*/
	void
	_mesa_update_stencil(GLcontext *ctx)
	{
	if (ctx->Extensions.EXT_stencil_two_side) {
	ctx->Stencil._TestTwoSide = ctx->Stencil.TestTwoSide;
	}
	else {
	ctx->Stencil._TestTwoSide =
	(ctx->Stencil.Function[0] != ctx->Stencil.Function[1] \|\|
	ctx->Stencil.FailFunc[0] != ctx->Stencil.FailFunc[1] \|\|
	ctx->Stencil.ZPassFunc[0] != ctx->Stencil.ZPassFunc[1] \|\|
	ctx->Stencil.ZFailFunc[0] != ctx->Stencil.ZFailFunc[1] \|\|
	ctx->Stencil.Ref[0] != ctx->Stencil.Ref[1] \|\|
	ctx->Stencil.ValueMask[0] != ctx->Stencil.ValueMask[1] \|\|
	ctx->Stencil.WriteMask[0] != ctx->Stencil.WriteMask[1]);
	}
	}


	/**
	* Initialize the context stipple state.
	*
	* \param ctx GL context.
	*
	* Initializes __GLcontextRec::Stencil attribute group.
	*/
	void
	_mesa_init_stencil(GLcontext *ctx)
	{
	ctx->Stencil.Enabled = GL_FALSE;
	ctx->Stencil.TestTwoSide = GL_FALSE;
	ctx->Stencil.ActiveFace = 0; /* 0 = GL_FRONT, 1 = GL_BACK */
	ctx->Stencil.Function[0] = GL_ALWAYS;
	ctx->Stencil.Function[1] = GL_ALWAYS;
	ctx->Stencil.FailFunc[0] = GL_KEEP;
	ctx->Stencil.FailFunc[1] = GL_KEEP;
	ctx->Stencil.ZPassFunc[0] = GL_KEEP;
	ctx->Stencil.ZPassFunc[1] = GL_KEEP;
	ctx->Stencil.ZFailFunc[0] = GL_KEEP;
	ctx->Stencil.ZFailFunc[1] = GL_KEEP;
	ctx->Stencil.Ref[0] = 0;
	ctx->Stencil.Ref[1] = 0;
	ctx->Stencil.ValueMask[0] = ~0U;
	ctx->Stencil.ValueMask[1] = ~0U;
	ctx->Stencil.WriteMask[0] = ~0U;
	ctx->Stencil.WriteMask[1] = ~0U;
	ctx->Stencil.Clear = 0;
	}