text: /**
   * \file points.c
   * Point operations.
   */
  
  /*
   * Mesa 3-D graphics library
   * Version:  7.0.3
   *
   * 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.
   */
  
  
  #include "glheader.h"
  #include "context.h"
  #include "macros.h"
  #include "points.h"
  #include "texstate.h"
  #include "mtypes.h"
  
  
  /**
   * Set current point size.
   * \param size  point diameter in pixels
   * \sa glPointSize().
   */
  void GLAPIENTRY
  _mesa_PointSize(GLfloat size)
  {
      GET_CURRENT_CONTEXT(ctx);
      ASSERT_OUTSIDE_BEGIN_END(ctx);
  
      if (size <= 0.0) {
  	_mesa_error(ctx, GL_INVALID_VALUE, "glPointSize");
  	return;
      }
  
      if (ctx->Point.Size == size)
  	return;
  
      FLUSH_VERTICES(ctx, _NEW_POINT);
      ctx->Point.Size = size;
      /* _Size is only used for non-attenuated path */
      ctx->Point._Size = CLAMP(ctx->Point.Size,
  			     ctx->Point.MinSize,
  			     ctx->Point.MaxSize);
  
      if (ctx->Driver.PointSize)
  	ctx->Driver.PointSize(ctx, size);
  }
  
  
  #if _HAVE_FULL_GL
  
  /*
   * Added by GL_NV_point_sprite
   */
  void GLAPIENTRY
  _mesa_PointParameteriNV(GLenum pname, GLint param)
  {
      GLfloat value[3] = {0.0};
      value[0] = (GLfloat)param;
      _mesa_PointParameterfvEXT(pname, &value);
  }
  
  
  /*
   * Added by GL_NV_point_sprite
   */
  void GLAPIENTRY
  _mesa_PointParameterivNV(GLenum pname, const GLint *params)
  {
      GLfloat p[3];
      p[0] = (GLfloat) params[0];
      if (pname == GL_DISTANCE_ATTENUATION_EXT) {
  	p[1] = (GLfloat) params[1];
  	p[2] = (GLfloat) params[2];
      }
      _mesa_PointParameterfvEXT(pname, p);
  }
  
  
  
  /*
   * Same for both GL_EXT_point_parameters and GL_ARB_point_parameters.
   */
  void GLAPIENTRY
  _mesa_PointParameterfEXT(GLenum pname, GLfloat param)
  {
      GLfloat p[3] = {0.0};
      p[0] = param;
      _mesa_PointParameterfvEXT(pname, p);
  }
  
  
  
  /*
   * Same for both GL_EXT_point_parameters and GL_ARB_point_parameters.
   */
  void GLAPIENTRY
  _mesa_PointParameterfvEXT(GLenum pname, const GLfloat *params)
  {
      GET_CURRENT_CONTEXT(ctx);
      ASSERT_OUTSIDE_BEGIN_END(ctx);
  
      switch (pname) {
  	case GL_DISTANCE_ATTENUATION_EXT:
  	    if (ctx->Extensions.EXT_point_parameters) {
  		if (TEST_EQ_3V(ctx->Point.Params, params))
  		    return;
  		FLUSH_VERTICES(ctx, _NEW_POINT);
  		COPY_3V(ctx->Point.Params, params);
  
  		ctx->Point._Attenuated = (ctx->Point.Params[0] != 1.0 ||
  					  ctx->Point.Params[1] != 0.0 ||
  					  ctx->Point.Params[2] != 0.0);
  
  		if (ctx->Point._Attenuated)
  		    ctx->_TriangleCaps |= DD_POINT_ATTEN;
  		else
  		    ctx->_TriangleCaps &= ~DD_POINT_ATTEN;
  	    } else {
  		_mesa_error(ctx, GL_INVALID_ENUM,
  			    "glPointParameterf[v]{EXT,ARB}(pname)");
  		return;
  	    }
  	    break;
  	case GL_POINT_SIZE_MIN_EXT:
  	    if (ctx->Extensions.EXT_point_parameters) {
  		if (params[0] < 0.0F) {
  		    _mesa_error(ctx, GL_INVALID_VALUE,
  				"glPointParameterf[v]{EXT,ARB}(param)");
  		    return;
  		}
  		if (ctx->Point.MinSize == params[0])
  		    return;
  		FLUSH_VERTICES(ctx, _NEW_POINT);
  		ctx->Point.MinSize = params[0];
  		/* re-clamp _Size */
  		ctx->Point._Size = CLAMP(ctx->Point.Size,
  					 ctx->Point.MinSize,
  					 ctx->Point.MaxSize);
  	    } else {
  		_mesa_error(ctx, GL_INVALID_ENUM,
  			    "glPointParameterf[v]{EXT,ARB}(pname)");
  		return;
  	    }
  	    break;
  	case GL_POINT_SIZE_MAX_EXT:
  	    if (ctx->Extensions.EXT_point_parameters) {
  		if (params[0] < 0.0F) {
  		    _mesa_error(ctx, GL_INVALID_VALUE,
  				"glPointParameterf[v]{EXT,ARB}(param)");
  		    return;
  		}
  		if (ctx->Point.MaxSize == params[0])
  		    return;
  		FLUSH_VERTICES(ctx, _NEW_POINT);
  		ctx->Point.MaxSize = params[0];
  		/* re-clamp _Size */
  		ctx->Point._Size = CLAMP(ctx->Point.Size,
  					 ctx->Point.MinSize,
  					 ctx->Point.MaxSize);
  	    } else {
  		_mesa_error(ctx, GL_INVALID_ENUM,
  			    "glPointParameterf[v]{EXT,ARB}(pname)");
  		return;
  	    }
  	    break;
  	case GL_POINT_FADE_THRESHOLD_SIZE_EXT:
  	    if (ctx->Extensions.EXT_point_parameters) {
  		if (params[0] < 0.0F) {
  		    _mesa_error(ctx, GL_INVALID_VALUE,
  				"glPointParameterf[v]{EXT,ARB}(param)");
  		    return;
  		}
  		if (ctx->Point.Threshold == params[0])
  		    return;
  		FLUSH_VERTICES(ctx, _NEW_POINT);
  		ctx->Point.Threshold = params[0];
  	    } else {
  		_mesa_error(ctx, GL_INVALID_ENUM,
  			    "glPointParameterf[v]{EXT,ARB}(pname)");
  		return;
  	    }
  	    break;
  	case GL_POINT_SPRITE_R_MODE_NV:
  	    /* This is one area where ARB_point_sprite and NV_point_sprite
  	     * differ.  In ARB_point_sprite the POINT_SPRITE_R_MODE is
  	     * always ZERO.  NV_point_sprite adds the S and R modes.
  	     */
  	    if (ctx->Extensions.NV_point_sprite) {
  		GLenum value = (GLenum) params[0];
  		if (value != GL_ZERO && value != GL_S && value != GL_R) {
  		    _mesa_error(ctx, GL_INVALID_VALUE,
  				"glPointParameterf[v]{EXT,ARB}(param)");
  		    return;
  		}
  		if (ctx->Point.SpriteRMode == value)
  		    return;
  		FLUSH_VERTICES(ctx, _NEW_POINT);
  		ctx->Point.SpriteRMode = value;
  	    } else {
  		_mesa_error(ctx, GL_INVALID_ENUM,
  			    "glPointParameterf[v]{EXT,ARB}(pname)");
  		return;
  	    }
  	    break;
  	case GL_POINT_SPRITE_COORD_ORIGIN:
  	    if (ctx->Extensions.ARB_point_sprite) {
  		GLenum value = (GLenum) params[0];
  		if (value != GL_LOWER_LEFT && value != GL_UPPER_LEFT) {
  		    _mesa_error(ctx, GL_INVALID_VALUE,
  				"glPointParameterf[v]{EXT,ARB}(param)");
  		    return;
  		}
  		if (ctx->Point.SpriteOrigin == value)
  		    return;
  		FLUSH_VERTICES(ctx, _NEW_POINT);
  		ctx->Point.SpriteOrigin = value;
  	    } else {
  		_mesa_error(ctx, GL_INVALID_ENUM,
  			    "glPointParameterf[v]{EXT,ARB}(pname)");
  		return;
  	    }
  	    break;
  	default:
  	    _mesa_error(ctx, GL_INVALID_ENUM,
  			"glPointParameterf[v]{EXT,ARB}(pname)");
  	    return;
      }
  
      if (ctx->Driver.PointParameterfv)
  	(*ctx->Driver.PointParameterfv)(ctx, pname, params);
  }
  #endif
  
  
  
  /**
   * Initialize the context point state.
   *
   * \param ctx GL context.
   *
   * Initializes __GLcontextRec::Point and point related constants in
   * __GLcontextRec::Const.
   */
  void
  _mesa_init_point(GLcontext *ctx)
  {
      GLuint i;
  
      ctx->Point.SmoothFlag = GL_FALSE;
      ctx->Point.Size = 1.0;
      ctx->Point._Size = 1.0;
      ctx->Point.Params[0] = 1.0;
      ctx->Point.Params[1] = 0.0;
      ctx->Point.Params[2] = 0.0;
      ctx->Point._Attenuated = GL_FALSE;
      ctx->Point.MinSize = 0.0;
      ctx->Point.MaxSize
  	= MAX2(ctx->Const.MaxPointSize, ctx->Const.MaxPointSizeAA);
      ctx->Point.Threshold = 1.0;
      ctx->Point.PointSprite = GL_FALSE; /* GL_ARB/NV_point_sprite */
      ctx->Point.SpriteRMode = GL_ZERO; /* GL_NV_point_sprite (only!) */
      ctx->Point.SpriteOrigin = GL_UPPER_LEFT; /* GL_ARB_point_sprite */
      for (i = 0; i < MAX_TEXTURE_UNITS; i++) {
  	ctx->Point.CoordReplace[i] = GL_FALSE; /* GL_ARB/NV_point_sprite */
      }
  }
  
  /*
   * Local Variables:
   * tab-width: 8
   * mode: C
   * indent-tabs-mode: t
   * c-file-style: "stroustrup"
   * End:
   * ex: shiftwidth=4 tabstop=8
   */
  