src/texsourc/lib/libhpdf/src/hpdf_ext_gstate.c

   1 /*
   2  * << Haru Free PDF Library >> -- hpdf_ext_gstate.c
   3  *
   4  * URL: http://libharu.org
   5  *
   6  * Copyright (c) 1999-2006 Takeshi Kanno <takeshi_kanno@est.hi-ho.ne.jp>
   7  * Copyright (c) 2007-2009 Antony Dovgal <tony@daylessday.org>
   8  *
   9  * Permission to use, copy, modify, distribute and sell this software
  10  * and its documentation for any purpose is hereby granted without fee,
  11  * provided that the above copyright notice appear in all copies and
  12  * that both that copyright notice and this permission notice appear
  13  * in supporting documentation.
  14  * It is provided "as is" without express or implied warranty.
  15  *
  16  */
  17
  18 #include "hpdf_conf.h"
  19 #include "hpdf_utils.h"
  20 #include "hpdf_ext_gstate.h"
  21 #include "hpdf.h"
  22
  23 static const char * const HPDF_BM_NAMES[] = {
  24                                       "Normal",
  25                                       "Multiply",
  26                                       "Screen",
  27                                       "Overlay",
  28                                       "Darken",
  29                                       "Lighten",
  30                                       "ColorDodge",
  31                                       "ColorBurn",
  32                                       "HardLight",
  33                                       "SoftLight",
  34                                       "Difference",
  35                                       "Exclusion"
  36                                       };
  37
  38
  39 HPDF_BOOL
  40 HPDF_ExtGState_Validate  (HPDF_ExtGState  ext_gstate)
  41 {
  42     if (!ext_gstate || (ext_gstate->header.obj_class !=
  43                 (HPDF_OSUBCLASS_EXT_GSTATE | HPDF_OCLASS_DICT) &&
  44                 ext_gstate->header.obj_class !=
  45                  (HPDF_OSUBCLASS_EXT_GSTATE_R | HPDF_OCLASS_DICT)))
  46         return HPDF_FALSE;
  47
  48     return HPDF_TRUE;
  49 }
  50
  51
  52 HPDF_STATUS
  53 ExtGState_Check  (HPDF_ExtGState  ext_gstate)
  54 {
  55     if (!HPDF_ExtGState_Validate (ext_gstate))
  56         return HPDF_INVALID_OBJECT;
  57
  58     if (ext_gstate->header.obj_class ==
  59             (HPDF_OSUBCLASS_EXT_GSTATE_R | HPDF_OCLASS_DICT))
  60         return HPDF_RaiseError (ext_gstate->error, HPDF_EXT_GSTATE_READ_ONLY,
  61                 0);
  62
  63     return HPDF_OK;
  64 }
  65
  66
  67 HPDF_Dict
  68 HPDF_ExtGState_New  (HPDF_MMgr   mmgr,
  69                      HPDF_Xref   xref)
  70 {
  71     HPDF_Dict obj = HPDF_Dict_New (mmgr);
  72
  73     HPDF_PTRACE ((" HPDF_ExtGState_New\n"));
  74
  75     if (!obj)
  76         return NULL;
  77
  78     if (HPDF_Xref_Add (xref, obj) != HPDF_OK)
  79         return NULL;
  80
  81     if (HPDF_Dict_AddName (obj, "Type", "ExtGState") != HPDF_OK)
  82         return NULL;
  83
  84     obj->header.obj_class |= HPDF_OSUBCLASS_EXT_GSTATE;
  85
  86     return obj;
  87 }
  88
  89
  90 HPDF_EXPORT(HPDF_STATUS)
  91 HPDF_ExtGState_SetAlphaStroke  (HPDF_ExtGState   ext_gstate,
  92                                 HPDF_REAL        value)
  93 {
  94     HPDF_STATUS ret = ExtGState_Check (ext_gstate);
  95
  96     if (ret != HPDF_OK)
  97         return ret;
  98
  99     if (value < 0 || value > 1.0f)
 100         return HPDF_RaiseError (ext_gstate->error,
 101                 HPDF_EXT_GSTATE_OUT_OF_RANGE, 0);
 102
 103     return HPDF_Dict_AddReal (ext_gstate, "CA", value);
 104 }
 105
 106
 107 HPDF_EXPORT(HPDF_STATUS)
 108 HPDF_ExtGState_SetAlphaFill  (HPDF_ExtGState   ext_gstate,
 109                               HPDF_REAL        value)
 110 {
 111     HPDF_STATUS ret = ExtGState_Check (ext_gstate);
 112
 113     if (ret != HPDF_OK)
 114         return ret;
 115
 116     if (value < 0 || value > 1.0f)
 117         return HPDF_RaiseError (ext_gstate->error,
 118                 HPDF_EXT_GSTATE_OUT_OF_RANGE, 0);
 119
 120     return HPDF_Dict_AddReal (ext_gstate, "ca", value);
 121 }
 122
 123
 124 HPDF_EXPORT(HPDF_STATUS)
 125 HPDF_ExtGState_SetBlendMode  (HPDF_ExtGState   ext_gstate,
 126                               HPDF_BlendMode   bmode)
 127 {
 128     HPDF_STATUS ret = ExtGState_Check (ext_gstate);
 129
 130     if (ret != HPDF_OK)
 131         return ret;
 132
 133     if ((int)bmode < 0 || (int)bmode > (int)HPDF_BM_EOF)
 134         return HPDF_RaiseError (ext_gstate->error,
 135                 HPDF_EXT_GSTATE_OUT_OF_RANGE, 0);
 136
 137     return HPDF_Dict_AddName (ext_gstate, "BM", HPDF_BM_NAMES[(int)bmode]);
 138 }
 139
 140 /*
 141 HPDF_STATUS
 142 HPDF_ExtGState_SetStrokeAdjustment  (HPDF_ExtGState   ext_gstate,
 143                                      HPDF_BOOL        value)
 144 {
 145     HPDF_STATUS ret = ExtGState_Check (ext_gstate);
 146
 147     if (ret != HPDF_OK)
 148         return ret;
 149
 150     return HPDF_Dict_AddBoolean (ext_gstate, "SA", value);
 151 }
 152 */
 153