src/mesa/main/feedback.c - platform/external/mesa3d - Git at Google

 /*
  * Mesa 3-D graphics library
  *
  * Copyright (C) 1999-2008  Brian Paul   All Rights Reserved.
  * Copyright (C) 2009  VMware, Inc.  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
  * THE AUTHORS OR COPYRIGHT HOLDERS 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 feedback.c
  * Selection and feedback modes functions.
  */


 #include "glheader.h"
 #include "context.h"
 #include "enums.h"
 #include "feedback.h"
 #include "macros.h"
 #include "mtypes.h"
 #include "main/dispatch.h"


 #define FB_3D		0x01
 #define FB_4D		0x02
 #define FB_COLOR	0x04
 #define FB_TEXTURE	0X08


 void GLAPIENTRY
 _mesa_FeedbackBuffer( GLsizei size, GLenum type, GLfloat *buffer )
 {
    GET_CURRENT_CONTEXT(ctx);

    if (ctx->RenderMode==GL_FEEDBACK) {
       _mesa_error( ctx, GL_INVALID_OPERATION, "glFeedbackBuffer" );
       return;
    }
    if (size<0) {
       _mesa_error( ctx, GL_INVALID_VALUE, "glFeedbackBuffer(size<0)" );
       return;
    }
    if (!buffer && size > 0) {
       _mesa_error( ctx, GL_INVALID_VALUE, "glFeedbackBuffer(buffer==NULL)" );
       ctx->Feedback.BufferSize = 0;
       return;
    }

    switch (type) {
       case GL_2D:
 	 ctx->Feedback._Mask = 0;
 	 break;
       case GL_3D:
 	 ctx->Feedback._Mask = FB_3D;
 	 break;
       case GL_3D_COLOR:
 	 ctx->Feedback._Mask = (FB_3D | FB_COLOR);
 	 break;
       case GL_3D_COLOR_TEXTURE:
 	 ctx->Feedback._Mask = (FB_3D | FB_COLOR | FB_TEXTURE);
 	 break;
       case GL_4D_COLOR_TEXTURE:
 	 ctx->Feedback._Mask = (FB_3D | FB_4D | FB_COLOR | FB_TEXTURE);
 	 break;
       default:
          _mesa_error( ctx, GL_INVALID_ENUM, "glFeedbackBuffer" );
 	 return;
    }

    FLUSH_VERTICES(ctx, _NEW_RENDERMODE); /* Always flush */
    ctx->Feedback.Type = type;
    ctx->Feedback.BufferSize = size;
    ctx->Feedback.Buffer = buffer;
    ctx->Feedback.Count = 0;	              /* Because of this. */
 }


 void GLAPIENTRY
 _mesa_PassThrough( GLfloat token )
 {
    GET_CURRENT_CONTEXT(ctx);

    if (ctx->RenderMode==GL_FEEDBACK) {
       FLUSH_VERTICES(ctx, 0);
       _mesa_feedback_token( ctx, (GLfloat) (GLint) GL_PASS_THROUGH_TOKEN );
       _mesa_feedback_token( ctx, token );
    }
 }


 /**
  * Put a vertex into the feedback buffer.
  */
 void
 _mesa_feedback_vertex(struct gl_context *ctx,
                       const GLfloat win[4],
                       const GLfloat color[4],
                       const GLfloat texcoord[4])
 {
    _mesa_feedback_token( ctx, win[0] );
    _mesa_feedback_token( ctx, win[1] );
    if (ctx->Feedback._Mask & FB_3D) {
       _mesa_feedback_token( ctx, win[2] );
    }
    if (ctx->Feedback._Mask & FB_4D) {
       _mesa_feedback_token( ctx, win[3] );
    }
    if (ctx->Feedback._Mask & FB_COLOR) {
       _mesa_feedback_token( ctx, color[0] );
       _mesa_feedback_token( ctx, color[1] );
       _mesa_feedback_token( ctx, color[2] );
       _mesa_feedback_token( ctx, color[3] );
    }
    if (ctx->Feedback._Mask & FB_TEXTURE) {
       _mesa_feedback_token( ctx, texcoord[0] );
       _mesa_feedback_token( ctx, texcoord[1] );
       _mesa_feedback_token( ctx, texcoord[2] );
       _mesa_feedback_token( ctx, texcoord[3] );
    }
 }


 /**********************************************************************/
 /** \name Selection */
 /*@{*/

 /**
  * Establish a buffer for selection mode values.
  *
  * \param size buffer size.
  * \param buffer buffer.
  *
  * \sa glSelectBuffer().
  *
  * \note this function can't be put in a display list.
  *
  * Verifies we're not in selection mode, flushes the vertices and initialize
  * the fields in __struct gl_contextRec::Select with the given buffer.
  */
 void GLAPIENTRY
 _mesa_SelectBuffer( GLsizei size, GLuint *buffer )
 {
    GET_CURRENT_CONTEXT(ctx);

    if (size < 0) {
       _mesa_error(ctx, GL_INVALID_VALUE, "glSelectBuffer(size)");
       return;
    }

    if (ctx->RenderMode==GL_SELECT) {
       _mesa_error( ctx, GL_INVALID_OPERATION, "glSelectBuffer" );
       return;			/* KW: added return */
    }

    FLUSH_VERTICES(ctx, _NEW_RENDERMODE);
    ctx->Select.Buffer = buffer;
    ctx->Select.BufferSize = size;
    ctx->Select.BufferCount = 0;
    ctx->Select.HitFlag = GL_FALSE;
    ctx->Select.HitMinZ = 1.0;
    ctx->Select.HitMaxZ = 0.0;
 }


 /**
  * Write a value of a record into the selection buffer.
  *
  * \param ctx GL context.
  * \param value value.
  *
  * Verifies there is free space in the buffer to write the value and
  * increments the pointer.
  */
 static inline void
 write_record(struct gl_context *ctx, GLuint value)
 {
    if (ctx->Select.BufferCount < ctx->Select.BufferSize) {
       ctx->Select.Buffer[ctx->Select.BufferCount] = value;
    }
    ctx->Select.BufferCount++;
 }


 /**
  * Update the hit flag and the maximum and minimum depth values.
  *
  * \param ctx GL context.
  * \param z depth.
  *
  * Sets gl_selection::HitFlag and updates gl_selection::HitMinZ and
  * gl_selection::HitMaxZ.
  */
 void
 _mesa_update_hitflag(struct gl_context *ctx, GLfloat z)
 {
    ctx->Select.HitFlag = GL_TRUE;
    if (z < ctx->Select.HitMinZ) {
       ctx->Select.HitMinZ = z;
    }
    if (z > ctx->Select.HitMaxZ) {
       ctx->Select.HitMaxZ = z;
    }
 }


 /**
  * Write the hit record.
  *
  * \param ctx GL context.
  *
  * Write the hit record, i.e., the number of names in the stack, the minimum and
  * maximum depth values and the number of names in the name stack at the time
  * of the event. Resets the hit flag.
  *
  * \sa gl_selection.
  */
 static void
 write_hit_record(struct gl_context *ctx)
 {
    GLuint i;
    GLuint zmin, zmax, zscale = (~0u);

    /* HitMinZ and HitMaxZ are in [0,1].  Multiply these values by */
    /* 2^32-1 and round to nearest unsigned integer. */

    assert( ctx != NULL ); /* this line magically fixes a SunOS 5.x/gcc bug */
    zmin = (GLuint) ((GLfloat) zscale * ctx->Select.HitMinZ);
    zmax = (GLuint) ((GLfloat) zscale * ctx->Select.HitMaxZ);

    write_record( ctx, ctx->Select.NameStackDepth );
    write_record( ctx, zmin );
    write_record( ctx, zmax );
    for (i = 0; i < ctx->Select.NameStackDepth; i++) {
       write_record( ctx, ctx->Select.NameStack[i] );
    }

    ctx->Select.Hits++;
    ctx->Select.HitFlag = GL_FALSE;
    ctx->Select.HitMinZ = 1.0;
    ctx->Select.HitMaxZ = -1.0;
 }


 /**
  * Initialize the name stack.
  *
  * Verifies we are in select mode and resets the name stack depth and resets
  * the hit record data in gl_selection. Marks new render mode in
  * __struct gl_contextRec::NewState.
  */
 void GLAPIENTRY
 _mesa_InitNames( void )
 {
    GET_CURRENT_CONTEXT(ctx);
    FLUSH_VERTICES(ctx, 0);

    /* Record the hit before the HitFlag is wiped out again. */
    if (ctx->RenderMode == GL_SELECT) {
       if (ctx->Select.HitFlag) {
          write_hit_record( ctx );
       }
    }
    ctx->Select.NameStackDepth = 0;
    ctx->Select.HitFlag = GL_FALSE;
    ctx->Select.HitMinZ = 1.0;
    ctx->Select.HitMaxZ = 0.0;
    ctx->NewState |= _NEW_RENDERMODE;
 }


 /**
  * Load the top-most name of the name stack.
  *
  * \param name name.
  *
  * Verifies we are in selection mode and that the name stack is not empty.
  * Flushes vertices. If there is a hit flag writes it (via write_hit_record()),
  * and replace the top-most name in the stack.
  *
  * sa __struct gl_contextRec::Select.
  */
 void GLAPIENTRY
 _mesa_LoadName( GLuint name )
 {
    GET_CURRENT_CONTEXT(ctx);

    if (ctx->RenderMode != GL_SELECT) {
       return;
    }
    if (ctx->Select.NameStackDepth == 0) {
       _mesa_error( ctx, GL_INVALID_OPERATION, "glLoadName" );
       return;
    }

    FLUSH_VERTICES(ctx, _NEW_RENDERMODE);

    if (ctx->Select.HitFlag) {
       write_hit_record( ctx );
    }
    if (ctx->Select.NameStackDepth < MAX_NAME_STACK_DEPTH) {
       ctx->Select.NameStack[ctx->Select.NameStackDepth-1] = name;
    }
    else {
       ctx->Select.NameStack[MAX_NAME_STACK_DEPTH-1] = name;
    }
 }


 /**
  * Push a name into the name stack.
  *
  * \param name name.
  *
  * Verifies we are in selection mode and that the name stack is not full.
  * Flushes vertices. If there is a hit flag writes it (via write_hit_record()),
  * and adds the name to the top of the name stack.
  *
  * sa __struct gl_contextRec::Select.
  */
 void GLAPIENTRY
 _mesa_PushName( GLuint name )
 {
    GET_CURRENT_CONTEXT(ctx);

    if (ctx->RenderMode != GL_SELECT) {
       return;
    }

    FLUSH_VERTICES(ctx, _NEW_RENDERMODE);
    if (ctx->Select.HitFlag) {
       write_hit_record( ctx );
    }
    if (ctx->Select.NameStackDepth >= MAX_NAME_STACK_DEPTH) {
       _mesa_error( ctx, GL_STACK_OVERFLOW, "glPushName" );
    }
    else
       ctx->Select.NameStack[ctx->Select.NameStackDepth++] = name;
 }


 /**
  * Pop a name into the name stack.
  *
  * Verifies we are in selection mode and that the name stack is not empty.
  * Flushes vertices. If there is a hit flag writes it (via write_hit_record()),
  * and removes top-most name in the name stack.
  *
  * sa __struct gl_contextRec::Select.
  */
 void GLAPIENTRY
 _mesa_PopName( void )
 {
    GET_CURRENT_CONTEXT(ctx);

    if (ctx->RenderMode != GL_SELECT) {
       return;
    }

    FLUSH_VERTICES(ctx, _NEW_RENDERMODE);
    if (ctx->Select.HitFlag) {
       write_hit_record( ctx );
    }
    if (ctx->Select.NameStackDepth == 0) {
       _mesa_error( ctx, GL_STACK_UNDERFLOW, "glPopName" );
    }
    else
       ctx->Select.NameStackDepth--;
 }

 /*@}*/


 /**********************************************************************/
 /** \name Render Mode */
 /*@{*/

 /**
  * Set rasterization mode.
  *
  * \param mode rasterization mode.
  *
  * \note this function can't be put in a display list.
  *
  * \sa glRenderMode().
  *
  * Flushes the vertices and do the necessary cleanup according to the previous
  * rasterization mode, such as writing the hit record or resent the select
  * buffer index when exiting the select mode. Updates
  * __struct gl_contextRec::RenderMode and notifies the driver via the
  * dd_function_table::RenderMode callback.
  */
 GLint GLAPIENTRY
 _mesa_RenderMode( GLenum mode )
 {
    GET_CURRENT_CONTEXT(ctx);
    GLint result;
    ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, 0);

    if (MESA_VERBOSE & VERBOSE_API)
       _mesa_debug(ctx, "glRenderMode %s\n", _mesa_enum_to_string(mode));

    FLUSH_VERTICES(ctx, _NEW_RENDERMODE);

    switch (ctx->RenderMode) {
       case GL_RENDER:
 	 result = 0;
 	 break;
       case GL_SELECT:
 	 if (ctx->Select.HitFlag) {
 	    write_hit_record( ctx );
 	 }
 	 if (ctx->Select.BufferCount > ctx->Select.BufferSize) {
 	    /* overflow */
 #ifdef DEBUG
             _mesa_warning(ctx, "Feedback buffer overflow");
 #endif
 	    result = -1;
 	 }
 	 else {
 	    result = ctx->Select.Hits;
 	 }
 	 ctx->Select.BufferCount = 0;
 	 ctx->Select.Hits = 0;
 	 ctx->Select.NameStackDepth = 0;
 	 break;
       case GL_FEEDBACK:
 	 if (ctx->Feedback.Count > ctx->Feedback.BufferSize) {
 	    /* overflow */
 	    result = -1;
 	 }
 	 else {
 	    result = ctx->Feedback.Count;
 	 }
 	 ctx->Feedback.Count = 0;
 	 break;
       default:
 	 _mesa_error( ctx, GL_INVALID_ENUM, "glRenderMode" );
 	 return 0;
    }

    switch (mode) {
       case GL_RENDER:
          break;
       case GL_SELECT:
 	 if (ctx->Select.BufferSize==0) {
 	    /* haven't called glSelectBuffer yet */
 	    _mesa_error( ctx, GL_INVALID_OPERATION, "glRenderMode" );
 	 }
 	 break;
       case GL_FEEDBACK:
 	 if (ctx->Feedback.BufferSize==0) {
 	    /* haven't called glFeedbackBuffer yet */
 	    _mesa_error( ctx, GL_INVALID_OPERATION, "glRenderMode" );
 	 }
 	 break;
       default:
 	 _mesa_error( ctx, GL_INVALID_ENUM, "glRenderMode" );
 	 return 0;
    }

    ctx->RenderMode = mode;
    if (ctx->Driver.RenderMode)
       ctx->Driver.RenderMode( ctx, mode );

    return result;
 }

 /*@}*/


 /**********************************************************************/
 /** \name Initialization */
 /*@{*/

 /**
  * Initialize context feedback data.
  */
 void _mesa_init_feedback( struct gl_context * ctx )
 {
    /* Feedback */
    ctx->Feedback.Type = GL_2D;   /* TODO: verify */
    ctx->Feedback.Buffer = NULL;
    ctx->Feedback.BufferSize = 0;
    ctx->Feedback.Count = 0;

    /* Selection/picking */
    ctx->Select.Buffer = NULL;
    ctx->Select.BufferSize = 0;
    ctx->Select.BufferCount = 0;
    ctx->Select.Hits = 0;
    ctx->Select.NameStackDepth = 0;

    /* Miscellaneous */
    ctx->RenderMode = GL_RENDER;
 }

 /*@}*/
	/*
	* Mesa 3-D graphics library
	*
	* Copyright (C) 1999-2008 Brian Paul All Rights Reserved.
	* Copyright (C) 2009 VMware, Inc. 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
	* THE AUTHORS OR COPYRIGHT HOLDERS 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 feedback.c
	* Selection and feedback modes functions.
	*/


	#include "glheader.h"
	#include "context.h"
	#include "enums.h"
	#include "feedback.h"
	#include "macros.h"
	#include "mtypes.h"
	#include "main/dispatch.h"


	#define FB_3D 0x01
	#define FB_4D 0x02
	#define FB_COLOR 0x04
	#define FB_TEXTURE 0X08



	void GLAPIENTRY
	_mesa_FeedbackBuffer( GLsizei size, GLenum type, GLfloat *buffer )
	{
	GET_CURRENT_CONTEXT(ctx);

	if (ctx->RenderMode==GL_FEEDBACK) {
	_mesa_error( ctx, GL_INVALID_OPERATION, "glFeedbackBuffer" );
	return;
	}
	if (size<0) {
	_mesa_error( ctx, GL_INVALID_VALUE, "glFeedbackBuffer(size<0)" );
	return;
	}
	if (!buffer && size > 0) {
	_mesa_error( ctx, GL_INVALID_VALUE, "glFeedbackBuffer(buffer==NULL)" );
	ctx->Feedback.BufferSize = 0;
	return;
	}

	switch (type) {
	case GL_2D:
	ctx->Feedback._Mask = 0;
	break;
	case GL_3D:
	ctx->Feedback._Mask = FB_3D;
	break;
	case GL_3D_COLOR:
	ctx->Feedback._Mask = (FB_3D \| FB_COLOR);
	break;
	case GL_3D_COLOR_TEXTURE:
	ctx->Feedback._Mask = (FB_3D \| FB_COLOR \| FB_TEXTURE);
	break;
	case GL_4D_COLOR_TEXTURE:
	ctx->Feedback._Mask = (FB_3D \| FB_4D \| FB_COLOR \| FB_TEXTURE);
	break;
	default:
	_mesa_error( ctx, GL_INVALID_ENUM, "glFeedbackBuffer" );
	return;
	}

	FLUSH_VERTICES(ctx, _NEW_RENDERMODE); /* Always flush */
	ctx->Feedback.Type = type;
	ctx->Feedback.BufferSize = size;
	ctx->Feedback.Buffer = buffer;
	ctx->Feedback.Count = 0; /* Because of this. */
	}


	void GLAPIENTRY
	_mesa_PassThrough( GLfloat token )
	{
	GET_CURRENT_CONTEXT(ctx);

	if (ctx->RenderMode==GL_FEEDBACK) {
	FLUSH_VERTICES(ctx, 0);
	_mesa_feedback_token( ctx, (GLfloat) (GLint) GL_PASS_THROUGH_TOKEN );
	_mesa_feedback_token( ctx, token );
	}
	}


	/**
	* Put a vertex into the feedback buffer.
	*/
	void
	_mesa_feedback_vertex(struct gl_context *ctx,
	const GLfloat win[4],
	const GLfloat color[4],
	const GLfloat texcoord[4])
	{
	_mesa_feedback_token( ctx, win[0] );
	_mesa_feedback_token( ctx, win[1] );
	if (ctx->Feedback._Mask & FB_3D) {
	_mesa_feedback_token( ctx, win[2] );
	}
	if (ctx->Feedback._Mask & FB_4D) {
	_mesa_feedback_token( ctx, win[3] );
	}
	if (ctx->Feedback._Mask & FB_COLOR) {
	_mesa_feedback_token( ctx, color[0] );
	_mesa_feedback_token( ctx, color[1] );
	_mesa_feedback_token( ctx, color[2] );
	_mesa_feedback_token( ctx, color[3] );
	}
	if (ctx->Feedback._Mask & FB_TEXTURE) {
	_mesa_feedback_token( ctx, texcoord[0] );
	_mesa_feedback_token( ctx, texcoord[1] );
	_mesa_feedback_token( ctx, texcoord[2] );
	_mesa_feedback_token( ctx, texcoord[3] );
	}
	}


	/**********************************************************************/
	/** \name Selection */
	/@{/

	/**
	* Establish a buffer for selection mode values.
	*
	* \param size buffer size.
	* \param buffer buffer.
	*
	* \sa glSelectBuffer().
	*
	* \note this function can't be put in a display list.
	*
	* Verifies we're not in selection mode, flushes the vertices and initialize
	* the fields in __struct gl_contextRec::Select with the given buffer.
	*/
	void GLAPIENTRY
	_mesa_SelectBuffer( GLsizei size, GLuint *buffer )
	{
	GET_CURRENT_CONTEXT(ctx);

	if (size < 0) {
	_mesa_error(ctx, GL_INVALID_VALUE, "glSelectBuffer(size)");
	return;
	}

	if (ctx->RenderMode==GL_SELECT) {
	_mesa_error( ctx, GL_INVALID_OPERATION, "glSelectBuffer" );
	return; /* KW: added return */
	}

	FLUSH_VERTICES(ctx, _NEW_RENDERMODE);
	ctx->Select.Buffer = buffer;
	ctx->Select.BufferSize = size;
	ctx->Select.BufferCount = 0;
	ctx->Select.HitFlag = GL_FALSE;
	ctx->Select.HitMinZ = 1.0;
	ctx->Select.HitMaxZ = 0.0;
	}


	/**
	* Write a value of a record into the selection buffer.
	*
	* \param ctx GL context.
	* \param value value.
	*
	* Verifies there is free space in the buffer to write the value and
	* increments the pointer.
	*/
	static inline void
	write_record(struct gl_context *ctx, GLuint value)
	{
	if (ctx->Select.BufferCount < ctx->Select.BufferSize) {
	ctx->Select.Buffer[ctx->Select.BufferCount] = value;
	}
	ctx->Select.BufferCount++;
	}


	/**
	* Update the hit flag and the maximum and minimum depth values.
	*
	* \param ctx GL context.
	* \param z depth.
	*
	* Sets gl_selection::HitFlag and updates gl_selection::HitMinZ and
	* gl_selection::HitMaxZ.
	*/
	void
	_mesa_update_hitflag(struct gl_context *ctx, GLfloat z)
	{
	ctx->Select.HitFlag = GL_TRUE;
	if (z < ctx->Select.HitMinZ) {
	ctx->Select.HitMinZ = z;
	}
	if (z > ctx->Select.HitMaxZ) {
	ctx->Select.HitMaxZ = z;
	}
	}


	/**
	* Write the hit record.
	*
	* \param ctx GL context.
	*
	* Write the hit record, i.e., the number of names in the stack, the minimum and
	* maximum depth values and the number of names in the name stack at the time
	* of the event. Resets the hit flag.
	*
	* \sa gl_selection.
	*/
	static void
	write_hit_record(struct gl_context *ctx)
	{
	GLuint i;
	GLuint zmin, zmax, zscale = (~0u);

	/* HitMinZ and HitMaxZ are in [0,1]. Multiply these values by */
	/* 2^32-1 and round to nearest unsigned integer. */

	assert( ctx != NULL ); /* this line magically fixes a SunOS 5.x/gcc bug */
	zmin = (GLuint) ((GLfloat) zscale * ctx->Select.HitMinZ);
	zmax = (GLuint) ((GLfloat) zscale * ctx->Select.HitMaxZ);

	write_record( ctx, ctx->Select.NameStackDepth );
	write_record( ctx, zmin );
	write_record( ctx, zmax );
	for (i = 0; i < ctx->Select.NameStackDepth; i++) {
	write_record( ctx, ctx->Select.NameStack[i] );
	}

	ctx->Select.Hits++;
	ctx->Select.HitFlag = GL_FALSE;
	ctx->Select.HitMinZ = 1.0;
	ctx->Select.HitMaxZ = -1.0;
	}


	/**
	* Initialize the name stack.
	*
	* Verifies we are in select mode and resets the name stack depth and resets
	* the hit record data in gl_selection. Marks new render mode in
	* __struct gl_contextRec::NewState.
	*/
	void GLAPIENTRY
	_mesa_InitNames( void )
	{
	GET_CURRENT_CONTEXT(ctx);
	FLUSH_VERTICES(ctx, 0);

	/* Record the hit before the HitFlag is wiped out again. */
	if (ctx->RenderMode == GL_SELECT) {
	if (ctx->Select.HitFlag) {
	write_hit_record( ctx );
	}
	}
	ctx->Select.NameStackDepth = 0;
	ctx->Select.HitFlag = GL_FALSE;
	ctx->Select.HitMinZ = 1.0;
	ctx->Select.HitMaxZ = 0.0;
	ctx->NewState \|= _NEW_RENDERMODE;
	}


	/**
	* Load the top-most name of the name stack.
	*
	* \param name name.
	*
	* Verifies we are in selection mode and that the name stack is not empty.
	* Flushes vertices. If there is a hit flag writes it (via write_hit_record()),
	* and replace the top-most name in the stack.
	*
	* sa __struct gl_contextRec::Select.
	*/
	void GLAPIENTRY
	_mesa_LoadName( GLuint name )
	{
	GET_CURRENT_CONTEXT(ctx);

	if (ctx->RenderMode != GL_SELECT) {
	return;
	}
	if (ctx->Select.NameStackDepth == 0) {
	_mesa_error( ctx, GL_INVALID_OPERATION, "glLoadName" );
	return;
	}

	FLUSH_VERTICES(ctx, _NEW_RENDERMODE);

	if (ctx->Select.HitFlag) {
	write_hit_record( ctx );
	}
	if (ctx->Select.NameStackDepth < MAX_NAME_STACK_DEPTH) {
	ctx->Select.NameStack[ctx->Select.NameStackDepth-1] = name;
	}
	else {
	ctx->Select.NameStack[MAX_NAME_STACK_DEPTH-1] = name;
	}
	}


	/**
	* Push a name into the name stack.
	*
	* \param name name.
	*
	* Verifies we are in selection mode and that the name stack is not full.
	* Flushes vertices. If there is a hit flag writes it (via write_hit_record()),
	* and adds the name to the top of the name stack.
	*
	* sa __struct gl_contextRec::Select.
	*/
	void GLAPIENTRY
	_mesa_PushName( GLuint name )
	{
	GET_CURRENT_CONTEXT(ctx);

	if (ctx->RenderMode != GL_SELECT) {
	return;
	}

	FLUSH_VERTICES(ctx, _NEW_RENDERMODE);
	if (ctx->Select.HitFlag) {
	write_hit_record( ctx );
	}
	if (ctx->Select.NameStackDepth >= MAX_NAME_STACK_DEPTH) {
	_mesa_error( ctx, GL_STACK_OVERFLOW, "glPushName" );
	}
	else
	ctx->Select.NameStack[ctx->Select.NameStackDepth++] = name;
	}


	/**
	* Pop a name into the name stack.
	*
	* Verifies we are in selection mode and that the name stack is not empty.
	* Flushes vertices. If there is a hit flag writes it (via write_hit_record()),
	* and removes top-most name in the name stack.
	*
	* sa __struct gl_contextRec::Select.
	*/
	void GLAPIENTRY
	_mesa_PopName( void )
	{
	GET_CURRENT_CONTEXT(ctx);

	if (ctx->RenderMode != GL_SELECT) {
	return;
	}

	FLUSH_VERTICES(ctx, _NEW_RENDERMODE);
	if (ctx->Select.HitFlag) {
	write_hit_record( ctx );
	}
	if (ctx->Select.NameStackDepth == 0) {
	_mesa_error( ctx, GL_STACK_UNDERFLOW, "glPopName" );
	}
	else
	ctx->Select.NameStackDepth--;
	}

	/@}/


	/**********************************************************************/
	/** \name Render Mode */
	/@{/

	/**
	* Set rasterization mode.
	*
	* \param mode rasterization mode.
	*
	* \note this function can't be put in a display list.
	*
	* \sa glRenderMode().
	*
	* Flushes the vertices and do the necessary cleanup according to the previous
	* rasterization mode, such as writing the hit record or resent the select
	* buffer index when exiting the select mode. Updates
	* __struct gl_contextRec::RenderMode and notifies the driver via the
	* dd_function_table::RenderMode callback.
	*/
	GLint GLAPIENTRY
	_mesa_RenderMode( GLenum mode )
	{
	GET_CURRENT_CONTEXT(ctx);
	GLint result;
	ASSERT_OUTSIDE_BEGIN_END_WITH_RETVAL(ctx, 0);

	if (MESA_VERBOSE & VERBOSE_API)
	_mesa_debug(ctx, "glRenderMode %s\n", _mesa_enum_to_string(mode));

	FLUSH_VERTICES(ctx, _NEW_RENDERMODE);

	switch (ctx->RenderMode) {
	case GL_RENDER:
	result = 0;
	break;
	case GL_SELECT:
	if (ctx->Select.HitFlag) {
	write_hit_record( ctx );
	}
	if (ctx->Select.BufferCount > ctx->Select.BufferSize) {
	/* overflow */
	#ifdef DEBUG
	_mesa_warning(ctx, "Feedback buffer overflow");
	#endif
	result = -1;
	}
	else {
	result = ctx->Select.Hits;
	}
	ctx->Select.BufferCount = 0;
	ctx->Select.Hits = 0;
	ctx->Select.NameStackDepth = 0;
	break;
	case GL_FEEDBACK:
	if (ctx->Feedback.Count > ctx->Feedback.BufferSize) {
	/* overflow */
	result = -1;
	}
	else {
	result = ctx->Feedback.Count;
	}
	ctx->Feedback.Count = 0;
	break;
	default:
	_mesa_error( ctx, GL_INVALID_ENUM, "glRenderMode" );
	return 0;
	}

	switch (mode) {
	case GL_RENDER:
	break;
	case GL_SELECT:
	if (ctx->Select.BufferSize==0) {
	/* haven't called glSelectBuffer yet */
	_mesa_error( ctx, GL_INVALID_OPERATION, "glRenderMode" );
	}
	break;
	case GL_FEEDBACK:
	if (ctx->Feedback.BufferSize==0) {
	/* haven't called glFeedbackBuffer yet */
	_mesa_error( ctx, GL_INVALID_OPERATION, "glRenderMode" );
	}
	break;
	default:
	_mesa_error( ctx, GL_INVALID_ENUM, "glRenderMode" );
	return 0;
	}

	ctx->RenderMode = mode;
	if (ctx->Driver.RenderMode)
	ctx->Driver.RenderMode( ctx, mode );

	return result;
	}

	/@}/


	/**********************************************************************/
	/** \name Initialization */
	/@{/

	/**
	* Initialize context feedback data.
	*/
	void _mesa_init_feedback( struct gl_context * ctx )
	{
	/* Feedback */
	ctx->Feedback.Type = GL_2D; /* TODO: verify */
	ctx->Feedback.Buffer = NULL;
	ctx->Feedback.BufferSize = 0;
	ctx->Feedback.Count = 0;

	/* Selection/picking */
	ctx->Select.Buffer = NULL;
	ctx->Select.BufferSize = 0;
	ctx->Select.BufferCount = 0;
	ctx->Select.Hits = 0;
	ctx->Select.NameStackDepth = 0;

	/* Miscellaneous */
	ctx->RenderMode = GL_RENDER;
	}

	/@}/