src/libs/print/libprint/HalftoneView.cpp

   1 #include "HalftoneView.h"
   2
   3 #include <Bitmap.h>
   4 #include <StringView.h>
   5
   6
   7 HalftonePreviewView::HalftonePreviewView(BRect frame, const char* name,
   8         uint32 resizeMask, uint32 flags)
   9         :
  10         BView(frame, name, resizeMask, flags)
  11 {
  12 }
  13
  14
  15 void
  16 HalftonePreviewView::Preview(float gamma, float min,
  17         Halftone::DitherType ditherType, bool color)
  18 {
  19         const color_space kColorSpace = B_RGB32;
  20         const float right = Bounds().Width();
  21         const float bottom = Bounds().Height();
  22         BRect rect(0, 0, right, bottom);
  23
  24         BBitmap testImage(rect, kColorSpace, true);
  25         BBitmap preview(rect, kColorSpace);
  26         BView view(rect, "", B_FOLLOW_ALL, B_WILL_DRAW);
  27
  28         // create test image
  29         testImage.Lock();
  30         testImage.AddChild(&view);
  31
  32         // color bars
  33         const int height = Bounds().IntegerHeight()+1;
  34         const int width  = Bounds().IntegerWidth()+1;
  35         const int delta  = height / 4;
  36         const float red_bottom   = delta - 1;
  37         const float green_bottom = red_bottom + delta;
  38         const float blue_bottom  = green_bottom + delta;
  39         const float gray_bottom  = height - 1;
  40
  41         for (int x = 0; x <= right; x ++) {
  42                 uchar value = x * 255 / width;
  43
  44                 BPoint from(x, 0);
  45                 BPoint to(x, red_bottom);
  46                 // red
  47                 view.SetHighColor(255, value, value);
  48                 view.StrokeLine(from, to);
  49                 // green
  50                 from.y = to.y+1;
  51                 to.y = green_bottom;
  52                 view.SetHighColor(value, 255, value);
  53                 view.StrokeLine(from, to);
  54                 // blue
  55                 from.y = to.y+1;
  56                 to.y = blue_bottom;
  57                 view.SetHighColor(value, value, 255);
  58                 view.StrokeLine(from, to);
  59                 // gray
  60                 from.y = to.y+1;
  61                 to.y = gray_bottom;
  62                 view.SetHighColor(value, value, value);
  63                 view.StrokeLine(from, to);
  64         }
  65
  66         view.Sync();
  67         testImage.RemoveChild(&view);
  68         testImage.Unlock();
  69
  70         // create preview image
  71         Halftone halftone(kColorSpace, gamma, min, ditherType);
  72         halftone.SetBlackValue(Halftone::kLowValueMeansBlack);
  73
  74         const int widthBytes = (width + 7) / 8; // byte boundary
  75         uchar* buffer = new uchar[widthBytes];
  76
  77         const uchar* src = (uchar*)testImage.Bits();
  78         uchar* dstRow = (uchar*)preview.Bits();
  79
  80         const int numPlanes = color ? 3 : 1;
  81         if (color) {
  82                 halftone.SetPlanes(Halftone::kPlaneRGB1);
  83         }
  84
  85         for (int y = 0; y < height; y ++) {
  86                 for (int plane = 0; plane < numPlanes;  plane ++) {
  87                         // halftone the preview image
  88                         halftone.Dither(buffer, src, 0, y, width);
  89
  90                         // convert the plane(s) to RGB32
  91                         ColorRGB32Little* dst = (ColorRGB32Little*)dstRow;
  92                         const uchar* bitmap = buffer;
  93                         for (int x = 0; x < width; x ++, dst ++) {
  94                                 const int bit = 7 - (x % 8);
  95                                 const bool isSet = (*bitmap & (1 << bit)) != 0;
  96                                 uchar value = isSet ? 255 : 0;
  97
  98                                 if (color) {
  99                                         switch (plane) {
 100                                                 case 0: dst->red = value;
 101                                                         break;
 102                                                 case 1: dst->green = value;
 103                                                         break;
 104                                                 case 2: dst->blue = value;
 105                                                         break;
 106                                         }
 107                                 } else {
 108                                         dst->red = dst->green = dst->blue = value;
 109                                 }
 110
 111                                 if (bit == 0) {
 112                                         bitmap ++;
 113                                 }
 114                         }
 115                 }
 116
 117                 // next row
 118                 src += testImage.BytesPerRow();
 119                 dstRow += preview.BytesPerRow();
 120         }
 121
 122         delete[] buffer;
 123
 124         SetViewBitmap(&preview);
 125         Invalidate();
 126 }
 127
 128
 129 HalftoneView::HalftoneView(BRect frame, const char* name, uint32 resizeMask,
 130         uint32 flags)
 131         :
 132         BView(frame, name, resizeMask, flags)
 133 {
 134         SetViewColor(ui_color(B_PANEL_BACKGROUND_COLOR));
 135
 136         BRect r(frame);
 137         float size, max;
 138
 139         r.OffsetTo(0, 0);
 140         const int height = r.IntegerHeight()+1;
 141         const int delta  = height / 4;
 142         const float red_top   = 0;
 143         const float green_top = delta;
 144         const float blue_top  = green_top + delta;
 145         const float gray_top  = r.bottom - delta;
 146
 147         const char* kRedLabel   = "Red: ";
 148         const char* kGreenLabel = "Green: ";
 149         const char* kBlueLabel  = "Blue: ";
 150         const char* kGrayLabel  = "Black: ";
 151
 152
 153         BFont font(be_plain_font);
 154         font_height fh;
 155         font.GetHeight(&fh);
 156
 157         max = size = font.StringWidth(kRedLabel);
 158         r.Set(0, 0, size, fh.ascent + fh.descent);
 159         r.OffsetTo(0, red_top);
 160         r.right = r.left + size;
 161         AddChild(new BStringView(r, "red", kRedLabel));
 162
 163         size = font.StringWidth(kGreenLabel);
 164         r.Set(0, 0, size, fh.ascent + fh.descent);
 165         if (max < size) max = size;
 166         r.OffsetTo(0, green_top);
 167         r.right = r.left + size;
 168         AddChild(new BStringView(r, "green", kGreenLabel));
 169
 170         size = font.StringWidth(kBlueLabel);
 171         r.Set(0, 0, size, fh.ascent + fh.descent);
 172         if (max < size) max = size;
 173         r.OffsetTo(0, blue_top);
 174         r.right = r.left + size;
 175         AddChild(new BStringView(r, "blue", kBlueLabel));
 176
 177         size = font.StringWidth(kGrayLabel);
 178         r.Set(0, 0, size, fh.ascent + fh.descent);
 179         if (max < size) max = size;
 180         r.OffsetTo(0, gray_top);
 181         r.right = r.left + size;
 182         AddChild(new BStringView(r, "gray", kGrayLabel));
 183
 184         r = frame;
 185         r.OffsetTo(max, 0);
 186         r.right -= max;
 187         fPreview = new HalftonePreviewView(r, "preview", resizeMask, flags);
 188         AddChild(fPreview);
 189 }
 190
 191
 192 void
 193 HalftoneView::Preview(float gamma, float min,
 194         Halftone::DitherType ditherType, bool color)
 195 {
 196         fPreview->Preview(gamma, min, ditherType, color);
 197 }