stencil.c File Reference

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Detailed Description

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.

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

Functions
static GLboolean	validate_stencil_op (GLcontext *ctx, GLenum op)
static GLboolean	validate_stencil_func (GLcontext *ctx, GLenum func)
void GLAPIENTRY	_mesa_ClearStencil (GLint s)
	Set the clear value for the stencil buffer.
void GLAPIENTRY	_mesa_StencilFuncSeparateATI (GLenum frontfunc, GLenum backfunc, GLint ref, GLuint mask)
	Set the function and reference value for stencil testing.
void GLAPIENTRY	_mesa_StencilFunc (GLenum func, GLint ref, GLuint mask)
	Set the function and reference value for stencil testing.
void GLAPIENTRY	_mesa_StencilMask (GLuint mask)
	Set the stencil writing mask.
void GLAPIENTRY	_mesa_StencilOp (GLenum fail, GLenum zfail, GLenum zpass)
	Set the stencil test actions.
void GLAPIENTRY	_mesa_ActiveStencilFaceEXT (GLenum face)
void GLAPIENTRY	_mesa_StencilOpSeparate (GLenum face, GLenum sfail, GLenum zfail, GLenum zpass)
	OpenGL 2.0 function.
void GLAPIENTRY	_mesa_StencilFuncSeparate (GLenum face, GLenum func, GLint ref, GLuint mask)
void GLAPIENTRY	_mesa_StencilMaskSeparate (GLenum face, GLuint mask)
void	_mesa_update_stencil (GLcontext *ctx)
	Update derived stencil state.
void	_mesa_init_stencil (GLcontext *ctx)
	Initialize the context stipple state.

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Function Documentation

void GLAPIENTRY _mesa_ActiveStencilFaceEXT

(

GLenum

face

)

void GLAPIENTRY _mesa_ClearStencil

(

GLint

s

)

Set the clear value for the stencil buffer.

Parameters:

s

clear value.

See also:

glClearStencil().

Updates gl_stencil_attrib::Clear. On change flushes the vertices and notifies the driver via the dd_function_table::ClearStencil callback.

void _mesa_init_stencil

(

GLcontext *

ctx

)

Initialize the context stipple state.

Parameters:

ctx

GL context.

Initializes __GLcontextRec::Stencil attribute group.

void GLAPIENTRY _mesa_StencilFunc	(	GLenum	func,
		GLint	ref,
		GLuint	mask
	)

Set the function and reference value for stencil testing.

Parameters:

	func	test function.
	ref	reference value.
	mask	bitmask.

See also:

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_StencilFuncSeparate	(	GLenum	face,
		GLenum	func,
		GLint	ref,
		GLuint	mask
	)

void GLAPIENTRY _mesa_StencilFuncSeparateATI	(	GLenum	frontfunc,
		GLenum	backfunc,
		GLint	ref,
		GLuint	mask
	)

Set the function and reference value for stencil testing.

Parameters:

	frontfunc	front test function.
	backfunc	back test function.
	ref	front and back reference value.
	mask	front and back bitmask.

See also:

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_StencilMask

(

GLuint

mask

)

Set the stencil writing mask.

Parameters:

mask

bit-mask to enable/disable writing of individual bits in the stencil planes.

See also:

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_StencilMaskSeparate	(	GLenum	face,
		GLuint	mask
	)

void GLAPIENTRY _mesa_StencilOp	(	GLenum	fail,
		GLenum	zfail,
		GLenum	zpass
	)

Set the stencil test actions.

Parameters:

	fail	action to take when stencil test fails.
	zfail	action to take when stencil test passes, but depth test fails.
	zpass	action to take when stencil test passes and the depth test passes (or depth testing is not enabled).

See also:

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_StencilOpSeparate	(	GLenum	face,
		GLenum	sfail,
		GLenum	zfail,
		GLenum	zpass
	)

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 _mesa_update_stencil

(

GLcontext *

ctx

)

Update derived stencil state.

static GLboolean validate_stencil_func	(	GLcontext *	ctx,
		GLenum	func
	)			[static]

static GLboolean validate_stencil_op	(	GLcontext *	ctx,
		GLenum	op
	)			[static]

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