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/*

 * 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_lookup_enum_by_nr(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;

}

/*@}*/