libjava/jni/gtk-peer/gnu_java_awt_peer_gtk_GtkImagePainter.c

   1 /* gtkimagepainter.c
   2    Copyright (C) 1999 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Classpath.
   5
   6 GNU Classpath is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2, or (at your option)
   9 any later version.
  10
  11 GNU Classpath is distributed in the hope that it will be useful, but
  12 WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Classpath; see the file COPYING.  If not, write to the
  18 Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  19 02111-1307 USA.
  20
  21 Linking this library statically or dynamically with other modules is
  22 making a combined work based on this library.  Thus, the terms and
  23 conditions of the GNU General Public License cover the whole
  24 combination.
  25
  26 As a special exception, the copyright holders of this library give you
  27 permission to link this library with independent modules to produce an
  28 executable, regardless of the license terms of these independent
  29 modules, and to copy and distribute the resulting executable under
  30 terms of your choice, provided that you also meet, for each linked
  31 independent module, the terms and conditions of the license of that
  32 module.  An independent module is a module which is not derived from
  33 or based on this library.  If you modify this library, you may extend
  34 this exception to your version of the library, but you are not
  35 obligated to do so.  If you do not wish to do so, delete this
  36 exception statement from your version. */
  37
  38 #include "gtkpeer.h"
  39 #include "gnu_java_awt_peer_gtk_GtkImagePainter.h"
  40 #include <libart_lgpl/art_misc.h>
  41 #include <libart_lgpl/art_rgb_affine.h>
  42
  43 #define SWAPU32(w) \
  44   (((w) << 24) | (((w) & 0xff00) << 8) | (((w) >> 8) & 0xff00) | ((w) >> 24))
  45
  46 JNIEXPORT void JNICALL Java_gnu_java_awt_peer_gtk_GtkImagePainter_drawPixels
  47 (JNIEnv *env, jobject obj, jobject gc_obj, jint bg_red, jint bg_green,
  48  jint bg_blue, jint x, jint y, jint width, jint height, jintArray jpixels,
  49  jint offset, jint scansize, jdoubleArray jaffine)
  50 {
  51   struct graphics *g;
  52   jint *pixels, *elems;
  53   guchar *packed;
  54   int i;
  55   jsize num_pixels;
  56   guchar *j_rgba, *c_rgb;
  57
  58   g = (struct graphics *) NSA_GET_PTR (env, gc_obj);
  59
  60   elems = (*env)->GetIntArrayElements (env, jpixels, NULL);
  61   num_pixels = (*env)->GetArrayLength (env, jpixels);
  62
  63   /* get a copy of the pixel data so we can modify it */
  64   pixels = malloc (sizeof (jint) * num_pixels);
  65   memcpy (pixels, elems, sizeof (jint) * num_pixels);
  66
  67   (*env)->ReleaseIntArrayElements (env, jpixels, elems, 0);
  68
  69 #ifndef WORDS_BIGENDIAN
  70   /* convert pixels from 0xBBGGRRAA to 0xAARRGGBB */
  71   for (i = 0; i < num_pixels; i++)
  72     pixels[i] = SWAPU32 ((unsigned)pixels[i]);
  73 #endif
  74
  75   packed = (guchar *) malloc (sizeof (guchar) * 3 * num_pixels);
  76   j_rgba = (guchar *) pixels;
  77   c_rgb = packed;
  78
  79   /* copy over pixels in DirectColorModel format to 24 bit RGB image data,
  80      and process the alpha channel */
  81   for (i = 0; i < num_pixels; i++)
  82     {
  83       jint ialpha = *j_rgba++;
  84
  85       switch (ialpha)
  86         {
  87         case 0:                 /* full transparency */
  88           *c_rgb++ = bg_red;
  89           *c_rgb++ = bg_green;
  90           *c_rgb++ = bg_blue;
  91           j_rgba += 3;
  92           break;
  93         case 255:               /* opaque */
  94           *c_rgb++ = *j_rgba++;
  95           *c_rgb++ = *j_rgba++;
  96           *c_rgb++ = *j_rgba++;
  97           break;
  98         default:                /* compositing required */
  99           {
 100             jfloat alpha = ialpha / 255.0;
 101             jfloat comp_alpha = 1.0 - alpha;
 102
 103             *c_rgb++ = *j_rgba++ * alpha + bg_red * comp_alpha;
 104             *c_rgb++ = *j_rgba++ * alpha + bg_green * comp_alpha;
 105             *c_rgb++ = *j_rgba++ * alpha + bg_blue * comp_alpha;
 106           }
 107           break;
 108         }
 109     }
 110
 111   if (jaffine)
 112     {
 113       jdouble *affine;
 114       ArtAlphaGamma *alphagamma = NULL;
 115       art_u8 *dst;
 116       int new_width, new_height;
 117       int i;
 118
 119       affine = (*env)->GetDoubleArrayElements (env, jaffine, NULL);
 120
 121       new_width = abs (width * affine[0]);
 122       new_height = abs (height * affine[3]);
 123
 124       dst = (art_u8 *) malloc (sizeof (art_u8) * 3 * (new_width * new_height));
 125
 126       art_rgb_affine (dst,
 127                       0, 0,
 128                       new_width, new_height,
 129                       new_width * 3,
 130                       (art_u8 *) packed + offset * 3,
 131                       width, height,
 132                       scansize * 3,
 133                       affine,
 134                       ART_FILTER_NEAREST,
 135                       alphagamma);
 136
 137       (*env)->ReleaseDoubleArrayElements (env, jaffine, affine, JNI_ABORT);
 138
 139       free (packed);
 140       packed = (guchar *) dst;
 141
 142       width = scansize = new_width;
 143       height = new_height;
 144       offset = 0;
 145     }
 146
 147   gdk_threads_enter ();
 148
 149   gdk_draw_rgb_image (g->drawable,
 150                       g->gc,
 151                       x + g->x_offset,
 152                       y + g->y_offset,
 153                       width, height, GDK_RGB_DITHER_NORMAL,
 154                       packed + offset * 3, scansize * 3);
 155
 156   gdk_threads_leave ();
 157
 158   free (pixels);
 159   free (packed);
 160 }