ref: 3cc7d630bdccc1f2ae4bbf97ba7fddcddeb470c5
parent: 87e4b339a3782f1e5dd230e4cdcd393441fc4891
author: David Turner <[email protected]>
date: Wed Sep 27 04:48:38 EDT 2006
adding missing file
--- /dev/null
+++ b/src/base/ftlcdfil.c
@@ -1,0 +1,169 @@
+#include <ft2build.h>
+#include FT_LCD_FILTER_H
+#include FT_IMAGE_H
+#include FT_INTERNAL_OBJECTS_H
+
+#ifdef FT_CONFIG_OPTION_SUBPIXEL_RENDERING
+
+ /* this function will be invoked from within the smooth
+ * rasterizer
+ */
+ static void
+ _ft_lcd_filter( FT_Bitmap* bitmap,
+ FT_Render_Mode mode,
+ FT_Byte* weights )
+ {+ FT_UInt width = (FT_UInt) bitmap->width;
+ FT_UInt height = (FT_UInt) bitmap->rows;
+
+ /* horizontal in-place FIR filter */
+ if ( mode == FT_RENDER_MODE_LCD && width >= 4 )
+ {+ FT_Byte* line = bitmap->buffer;
+
+ for ( ; height > 0; height--, line += bitmap->pitch )
+ {+ FT_UInt fir[5];
+ FT_UInt val1, xx;
+
+ val1 = line[0];
+ fir[0] = weights[2]*val1;
+ fir[1] = weights[3]*val1;
+ fir[2] = weights[4]*val1;
+ fir[3] = 0;
+ fir[4] = 0;
+
+
+ val1 = line[1];
+ fir[0] += weights[1]*val1;
+ fir[1] += weights[2]*val1;
+ fir[2] += weights[3]*val1;
+ fir[3] += weights[4]*val1;
+
+ for ( xx = 2; xx < width; xx++ )
+ {+ FT_UInt val, pix;
+
+ val = line[xx];
+ pix = fir[0] + weights[0]*val;
+ fir[0] = fir[1] + weights[1]*val;
+ fir[1] = fir[2] + weights[2]*val;
+ fir[2] = fir[3] + weights[3]*val;
+ fir[3] = weights[4]*val;
+
+ pix >>= 8;
+ pix |= -(pix >> 8);
+ line[xx-2] = (FT_Byte)pix;
+ }
+
+ {+ FT_UInt pix;
+
+ pix = fir[0] >> 8;
+ pix |= -(pix >> 8);
+ line[xx-2] = (FT_Byte)pix;
+
+ pix = fir[1] >> 8;
+ pix |= -(pix >> 8);
+ line[xx-1] = (FT_Byte)pix;
+ }
+ }
+ }
+ /* vertical in-place FIR filter */
+ else if ( mode == FT_RENDER_MODE_LCD_V && height >= 4 )
+ {+ FT_Byte* column = bitmap->buffer;
+ FT_Int pitch = bitmap->pitch;
+
+ for ( ; width > 0; width--, column++ )
+ {+ FT_Byte* col = column;
+ FT_UInt fir[5];
+ FT_UInt val1, yy;
+
+ val1 = col[0];
+ fir[0] = weights[2]*val1;
+ fir[1] = weights[3]*val1;
+ fir[2] = weights[4]*val1;
+ fir[3] = 0;
+ fir[4] = 0;
+ col += pitch;
+
+ val1 = col[0];
+ fir[0] += weights[1]*val1;
+ fir[1] += weights[2]*val1;
+ fir[2] += weights[3]*val1;
+ fir[3] += weights[4]*val1;
+ col += pitch;
+
+ for ( yy = 2; yy < height; yy++ )
+ {+ FT_UInt val, pix;
+
+ val = col[0];
+ pix = fir[0] + weights[0]*val;
+ fir[0] = fir[1] + weights[1]*val;
+ fir[1] = fir[2] + weights[2]*val;
+ fir[2] = fir[3] + weights[3]*val;
+ fir[3] = weights[4]*val;
+
+ pix >>= 8;
+ pix |= -(pix >> 8);
+ col[-2*pitch] = (FT_Byte)pix;
+ col += pitch;
+ }
+
+ {+ FT_UInt pix;
+
+ pix = fir[0] >> 8;
+ pix |= -(pix >> 8);
+ col[-2*pitch] = (FT_Byte)pix;
+
+ pix = fir[1] >> 8;
+ pix |= -(pix >> 8);
+ col[-pitch] = (FT_Byte)pix;
+ }
+ }
+ }
+ }
+
+
+ FT_EXPORT( FT_Error )
+ FT_Library_SetLcdFilter( FT_Library library,
+ const FT_Byte* filter_weights )
+ {+ static const FT_Byte default_filter[5] = { 0x10, 0x40, 0x70, 0x40, 0x10 };+
+ if ( library == NULL )
+ return FT_Err_Invalid_Argument;
+
+ if ( filter_weights == FT_LCD_FILTER_NONE )
+ {+ library->lcd_filter = NULL;
+ return 0;
+ }
+
+ if ( filter_weights == FT_LCD_FILTER_DEFAULT )
+ filter_weights = default_filter;
+
+ memcpy( library->lcd_filter_weights, filter_weights, 5 );
+ library->lcd_filter = _ft_lcd_filter;
+
+ return 0;
+ }
+
+#else
+
+ FT_EXPORT( FT_Error )
+ FT_Library_SetLcdFilter( FT_Library library,
+ const FT_Byte* filter_weights )
+ {+ FT_UNUSED(library);
+ FT_UNUSED(filter_weights);
+
+ return FT_Err_Unimplemented_Feature;
+ }
+
+
+#endif