Description: Add a Cairo LCD filter to use FreeType LCD colour filtering features

Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=404637

Bug-Cairo: http://bugs.freedesktop.org/show_bug.cgi?id=10301

diff --git a/config/system-headers b/config/system-headers

--- a/config/system-headers

+++ b/config/system-headers

@@ -267,16 +267,17 @@ Font.h

 Fonts.h

 fp.h

 fpieee.h

 frame/log.h

 frame/req.h

 freetype/freetype.h

 freetype/ftcache.h

 freetype/ftglyph.h

+freetype/ftlcdfil.h

 freetype/ftsynth.h

 freetype/ftoutln.h

 freetype/ttnameid.h

 freetype/tttables.h

 freetype/t1tables.h

 fribidi/fribidi.h

 FSp_fopen.h

 fstream

diff --git a/gfx/cairo/cairo/src/cairo-font-options.c b/gfx/cairo/cairo/src/cairo-font-options.c

--- a/gfx/cairo/cairo/src/cairo-font-options.c

+++ b/gfx/cairo/cairo/src/cairo-font-options.c

@@ -34,41 +34,44 @@

  *      Owen Taylor <otaylor@redhat.com>

  */

 #include "cairoint.h"

 static const cairo_font_options_t _cairo_font_options_nil = {

     CAIRO_ANTIALIAS_DEFAULT,

     CAIRO_SUBPIXEL_ORDER_DEFAULT,

+    CAIRO_LCD_FILTER_DEFAULT,

     CAIRO_HINT_STYLE_DEFAULT,

     CAIRO_HINT_METRICS_DEFAULT

 };

 /**

  * _cairo_font_options_init_default:

  * @options: a #cairo_font_options_t

  *

  * Initializes all fields of the font options object to default values.

  **/

 void

 _cairo_font_options_init_default (cairo_font_options_t *options)

 {

     options->antialias = CAIRO_ANTIALIAS_DEFAULT;

     options->subpixel_order = CAIRO_SUBPIXEL_ORDER_DEFAULT;

+    options->lcd_filter = CAIRO_LCD_FILTER_DEFAULT;

     options->hint_style = CAIRO_HINT_STYLE_DEFAULT;

     options->hint_metrics = CAIRO_HINT_METRICS_DEFAULT;

 }

 void

 _cairo_font_options_init_copy (cairo_font_options_t		*options,

 			       const cairo_font_options_t	*other)

 {

     options->antialias = other->antialias;

     options->subpixel_order = other->subpixel_order;

+    options->lcd_filter = other->lcd_filter;

     options->hint_style = other->hint_style;

     options->hint_metrics = other->hint_metrics;

 }

 /**

  * cairo_font_options_create:

  *

  * Allocates a new font options object with all options initialized

@@ -184,16 +187,18 @@ cairo_font_options_merge (cairo_font_opt

     if (cairo_font_options_status ((cairo_font_options_t *) other))

 	return;

     if (other->antialias != CAIRO_ANTIALIAS_DEFAULT)

 	options->antialias = other->antialias;

     if (other->subpixel_order != CAIRO_SUBPIXEL_ORDER_DEFAULT)

 	options->subpixel_order = other->subpixel_order;

+    if (other->lcd_filter != CAIRO_LCD_FILTER_DEFAULT)

+	options->lcd_filter = other->lcd_filter;

     if (other->hint_style != CAIRO_HINT_STYLE_DEFAULT)

 	options->hint_style = other->hint_style;

     if (other->hint_metrics != CAIRO_HINT_METRICS_DEFAULT)

 	options->hint_metrics = other->hint_metrics;

 }

 slim_hidden_def (cairo_font_options_merge);

 /**

@@ -216,16 +221,17 @@ cairo_font_options_equal (const cairo_fo

     if (cairo_font_options_status ((cairo_font_options_t *) other))

 	return FALSE;

     if (options == other)

 	return TRUE;

     return (options->antialias == other->antialias &&

 	    options->subpixel_order == other->subpixel_order &&

+	    options->lcd_filter == other->lcd_filter &&

 	    options->hint_style == other->hint_style &&

 	    options->hint_metrics == other->hint_metrics);

 }

 slim_hidden_def (cairo_font_options_equal);

 /**

  * cairo_font_options_hash:

  * @options: a #cairo_font_options_t

@@ -241,17 +247,18 @@ slim_hidden_def (cairo_font_options_equa

 unsigned long

 cairo_font_options_hash (const cairo_font_options_t *options)

 {

     if (cairo_font_options_status ((cairo_font_options_t *) options))

 	options = &_cairo_font_options_nil; /* force default values */

     return ((options->antialias) |

 	    (options->subpixel_order << 4) |

-	    (options->hint_style << 8) |

+	    (options->lcd_filter << 8) |

+	    (options->hint_style << 12) |

 	    (options->hint_metrics << 16));

 }

 slim_hidden_def (cairo_font_options_hash);

 /**

  * cairo_font_options_set_antialias:

  * @options: a #cairo_font_options_t

  * @antialias: the new antialiasing mode

@@ -323,16 +330,58 @@ cairo_font_options_get_subpixel_order (c

 {

     if (cairo_font_options_status ((cairo_font_options_t *) options))

 	return CAIRO_SUBPIXEL_ORDER_DEFAULT;

     return options->subpixel_order;

 }

 /**

+ * _cairo_font_options_set_lcd_filter:

+ * @options: a #cairo_font_options_t

+ * @lcd_filter: the new LCD filter

+ *

+ * Sets the LCD filter for the font options object. The LCD filter

+ * specifies how pixels are filtered when rendered with an antialiasing

+ * mode of %CAIRO_ANTIALIAS_SUBPIXEL. See the documentation for

+ * #cairo_lcd_filter_t for full details.

+ *

+ * Since: 1.8

+ **/

+void

+_cairo_font_options_set_lcd_filter (cairo_font_options_t *options,

+				    cairo_lcd_filter_t    lcd_filter)

+{

+    if (cairo_font_options_status (options))

+	return;

+

+    options->lcd_filter = lcd_filter;

+}

+

+/**

+ * _cairo_font_options_get_lcd_filter:

+ * @options: a #cairo_font_options_t

+ *

+ * Gets the LCD filter for the font options object.

+ * See the documentation for #cairo_lcd_filter_t for full details.

+ *

+ * Return value: the LCD filter for the font options object

+ *

+ * Since: 1.8

+ **/

+cairo_lcd_filter_t

+_cairo_font_options_get_lcd_filter (const cairo_font_options_t *options)

+{

+    if (cairo_font_options_status ((cairo_font_options_t *) options))

+	return CAIRO_LCD_FILTER_DEFAULT;

+

+    return options->lcd_filter;

+}

+

+/**

  * cairo_font_options_set_hint_style:

  * @options: a #cairo_font_options_t

  * @hint_style: the new hint style

  *

  * Sets the hint style for font outlines for the font options object.

  * This controls whether to fit font outlines to the pixel grid,

  * and if so, whether to optimize for fidelity or contrast.

  * See the documentation for #cairo_hint_style_t for full details.

diff --git a/gfx/cairo/cairo/src/cairo-ft-font.c b/gfx/cairo/cairo/src/cairo-ft-font.c

--- a/gfx/cairo/cairo/src/cairo-ft-font.c

+++ b/gfx/cairo/cairo/src/cairo-ft-font.c

@@ -54,16 +54,38 @@

 #include FT_FREETYPE_H

 #include FT_OUTLINE_H

 #include FT_IMAGE_H

 #include FT_TRUETYPE_TABLES_H

 #if HAVE_FT_GLYPHSLOT_EMBOLDEN

 #include FT_SYNTHESIS_H

 #endif

+#include FT_LCD_FILTER_H

+

+/* Fontconfig version older than 2.6 didn't have these options */

+#ifndef FC_LCD_FILTER

+#define FC_LCD_FILTER	"lcdfilter"

+#endif

+/* Some Ubuntu versions defined FC_LCD_FILTER without defining the following */

+#ifndef FC_LCD_NONE

+#define FC_LCD_NONE	0

+#define FC_LCD_DEFAULT	1

+#define FC_LCD_LIGHT	2

+#define FC_LCD_LEGACY	3

+#endif

+

+/* FreeType version older than 2.3.5(?) didn't have these options */

+#ifndef FT_LCD_FILTER_NONE

+#define FT_LCD_FILTER_NONE	0

+#define FT_LCD_FILTER_DEFAULT	1

+#define FT_LCD_FILTER_LIGHT	2

+#define FT_LCD_FILTER_LEGACY	16

+#endif

+

 #define DOUBLE_TO_26_6(d) ((FT_F26Dot6)((d) * 64.0))

 #define DOUBLE_FROM_26_6(t) ((double)(t) / 64.0)

 #define DOUBLE_TO_16_16(d) ((FT_Fixed)((d) * 65536.0))

 #define DOUBLE_FROM_16_16(t) ((double)(t) / 65536.0)

 /* This is the max number of FT_face objects we keep open at once

  */

 #define MAX_OPEN_FACES 10

@@ -774,45 +796,309 @@ _cairo_ft_unscaled_font_set_scale (cairo

 					unscaled->face->available_sizes[best_i].height);

 	if (error)

 	    return _cairo_error (CAIRO_STATUS_NO_MEMORY);

     }

     return CAIRO_STATUS_SUCCESS;

 }

-/* Empirically-derived subpixel filtering values thanks to Keith

- * Packard and libXft. */

-static const int    filters[3][3] = {

-    /* red */

-#if 0

-    {    65538*4/7,65538*2/7,65538*1/7 },

-    /* green */

-    {    65536*1/4, 65536*2/4, 65537*1/4 },

-    /* blue */

-    {    65538*1/7,65538*2/7,65538*4/7 },

+/* we sometimes need to convert the glyph bitmap in a FT_GlyphSlot

+ * into a different format. For example, we want to convert a

+ * FT_PIXEL_MODE_LCD or FT_PIXEL_MODE_LCD_V bitmap into a 32-bit

+ * ARGB or ABGR bitmap.

+ *

+ * this function prepares a target descriptor for this operation.

+ *

+ * input :: target bitmap descriptor. The function will set its

+ *          'width', 'rows' and 'pitch' fields, and only these

+ *

+ * slot  :: the glyph slot containing the source bitmap. this

+ *          function assumes that slot->format == FT_GLYPH_FORMAT_BITMAP

+ *

+ * mode  :: the requested final rendering mode. supported values are

+ *          MONO, NORMAL (i.e. gray), LCD and LCD_V

+ *

+ * the function returns the size in bytes of the corresponding buffer,

+ * it's up to the caller to allocate the corresponding memory block

+ * before calling _fill_xrender_bitmap

+ *

+ * it also returns -1 in case of error (e.g. incompatible arguments,

+ * like trying to convert a gray bitmap into a monochrome one)

+ */

+static int

+_compute_xrender_bitmap_size(FT_Bitmap      *target,

+			     FT_GlyphSlot    slot,

+			     FT_Render_Mode  mode)

+{

+    FT_Bitmap *ftbit;

+    int width, height, pitch;

+

+    if (slot->format != FT_GLYPH_FORMAT_BITMAP)

+	return -1;

+

+    /* compute the size of the final bitmap */

+    ftbit = &slot->bitmap;

+

+    width = ftbit->width;

+    height = ftbit->rows;

+    pitch = (width + 3) & ~3;

+

+    switch (ftbit->pixel_mode) {

+    case FT_PIXEL_MODE_MONO:

+	if (mode == FT_RENDER_MODE_MONO) {

+	    pitch = (((width + 31) & ~31) >> 3);

+	    break;

+	}

+	/* fall-through */

+

+    case FT_PIXEL_MODE_GRAY:

+	if (mode == FT_RENDER_MODE_LCD ||

+	    mode == FT_RENDER_MODE_LCD_V)

+	{

+	    /* each pixel is replicated into a 32-bit ARGB value */

+	    pitch = width * 4;

+	}

+	break;

+

+    case FT_PIXEL_MODE_LCD:

+	if (mode != FT_RENDER_MODE_LCD)

+	    return -1;

+

+	/* horz pixel triplets are packed into 32-bit ARGB values */

+	width /= 3;

+	pitch = width * 4;

+	break;

+

+    case FT_PIXEL_MODE_LCD_V:

+	if (mode != FT_RENDER_MODE_LCD_V)

+	    return -1;

+

+	/* vert pixel triplets are packed into 32-bit ARGB values */

+	height /= 3;

+	pitch = width * 4;

+	break;

+

+    default:  /* unsupported source format */

+	return -1;

+    }

+

+    target->width = width;

+    target->rows = height;

+    target->pitch = pitch;

+    target->buffer = NULL;

+

+    return pitch * height;

+}

+

+/* this functions converts the glyph bitmap found in a FT_GlyphSlot

+ * into a different format (see _compute_xrender_bitmap_size)

+ *

+ * you should call this function after _compute_xrender_bitmap_size

+ *

+ * target :: target bitmap descriptor. Note that its 'buffer' pointer

+ *           must point to memory allocated by the caller

+ *

+ * slot   :: the glyph slot containing the source bitmap

+ *

+ * mode   :: the requested final rendering mode

+ *

+ * bgr    :: boolean, set if BGR or VBGR pixel ordering is needed

+ */

+static void

+_fill_xrender_bitmap(FT_Bitmap      *target,

+		     FT_GlyphSlot    slot,

+		     FT_Render_Mode  mode,

+		     int             bgr)

+{

+    FT_Bitmap *ftbit = &slot->bitmap;

+    unsigned char *srcLine = ftbit->buffer;

+    unsigned char *dstLine = target->buffer;

+    int src_pitch = ftbit->pitch;

+    int width = target->width;

+    int height = target->rows;

+    int pitch = target->pitch;

+    int subpixel;

+    int h;

+

+    subpixel = (mode == FT_RENDER_MODE_LCD ||

+		mode == FT_RENDER_MODE_LCD_V);

+

+    if (src_pitch < 0)

+	srcLine -= src_pitch * (ftbit->rows - 1);

+

+    target->pixel_mode = ftbit->pixel_mode;

+

+    switch (ftbit->pixel_mode) {

+    case FT_PIXEL_MODE_MONO:

+	if (subpixel) {

+	    /* convert mono to ARGB32 values */

+

+	    for (h = height; h > 0; h--, srcLine += src_pitch, dstLine += pitch) {

+		int x;

+

+		for (x = 0; x < width; x++) {

+		    if (srcLine[(x >> 3)] & (0x80 >> (x & 7)))

+			((unsigned int *) dstLine)[x] = 0xffffffffU;

+		}

+	    }

+	    target->pixel_mode = FT_PIXEL_MODE_LCD;

+

+	} else if (mode == FT_RENDER_MODE_NORMAL) {

+	    /* convert mono to 8-bit gray */

+

+	    for (h = height; h > 0; h--, srcLine += src_pitch, dstLine += pitch) {

+		int x;

+

+		for (x = 0; x < width; x++) {

+		    if (srcLine[(x >> 3)] & (0x80 >> (x & 7)))

+			dstLine[x] = 0xff;

+		}

+	    }

+	    target->pixel_mode = FT_PIXEL_MODE_GRAY;

+

+	} else {

+	    /* copy mono to mono */

+

+	    int  bytes = (width + 7) >> 3;

+

+	    for (h = height; h > 0; h--, srcLine += src_pitch, dstLine += pitch)

+		memcpy (dstLine, srcLine, bytes);

+	}

+	break;

+

+    case FT_PIXEL_MODE_GRAY:

+	if (subpixel) {

+	    /* convert gray to ARGB32 values */

+

+	    for (h = height; h > 0; h--, srcLine += src_pitch, dstLine += pitch) {

+		int x;

+		unsigned int *dst = (unsigned int *) dstLine;

+

+		for (x = 0; x < width; x++) {

+		    unsigned int pix = srcLine[x];

+

+		    pix |= (pix << 8);

+		    pix |= (pix << 16);

+

+		    dst[x] = pix;

+		}

+	    }

+	    target->pixel_mode = FT_PIXEL_MODE_LCD;

+        } else {

+            /* copy gray into gray */

+

+            for (h = height; h > 0; h--, srcLine += src_pitch, dstLine += pitch)

+                memcpy (dstLine, srcLine, width);

+        }

+        break;

+

+    case FT_PIXEL_MODE_LCD:

+	if (!bgr) {

+	    /* convert horizontal RGB into ARGB32 */

+

+	    for (h = height; h > 0; h--, srcLine += src_pitch, dstLine += pitch) {

+		int x;

+		unsigned char *src = srcLine;

+		unsigned int *dst = (unsigned int *) dstLine;

+

+		for (x = 0; x < width; x++, src += 3) {

+		    unsigned int  pix;

+

+		    pix = ((unsigned int)src[0] << 16) |

+			  ((unsigned int)src[1] <<  8) |

+			  ((unsigned int)src[2]      ) |

+			  ((unsigned int)src[1] << 24) ;

+

+		    dst[x] = pix;

+		}

+	    }

+	} else {

+	    /* convert horizontal BGR into ARGB32 */

+

+	    for (h = height; h > 0; h--, srcLine += src_pitch, dstLine += pitch) {

+

+		int x;

+		unsigned char *src = srcLine;

+		unsigned int *dst = (unsigned int *) dstLine;

+

+		for (x = 0; x < width; x++, src += 3) {

+		    unsigned int  pix;

+

+		    pix = ((unsigned int)src[2] << 16) |

+			  ((unsigned int)src[1] <<  8) |

+			  ((unsigned int)src[0]      ) |

+			  ((unsigned int)src[1] << 24) ;

+

+		    dst[x] = pix;

+		}

+	    }

+	}

+	break;

+

+    default:  /* FT_PIXEL_MODE_LCD_V */

+	/* convert vertical RGB into ARGB32 */

+	if (!bgr) {

+

+	    for (h = height; h > 0; h--, srcLine += 3 * src_pitch, dstLine += pitch) {

+		int x;

+		unsigned char* src = srcLine;

+		unsigned int*  dst = (unsigned int *) dstLine;

+

+		for (x = 0; x < width; x++, src += 1) {

+		    unsigned int pix;

+#if 1

+		    pix = ((unsigned int)src[0]           << 16) |

+			  ((unsigned int)src[src_pitch]   <<  8) |

+			  ((unsigned int)src[src_pitch*2]      ) |

+			  0xFF000000 ;

+#else

+		    pix = ((unsigned int)src[0]           << 16) |

+			  ((unsigned int)src[src_pitch]   <<  8) |

+			  ((unsigned int)src[src_pitch*2]      ) |

+			  ((unsigned int)src[src_pitch]   << 24) ;

 #endif

-    {    65538*9/13,65538*3/13,65538*1/13 },

-    /* green */

-    {    65538*1/6, 65538*4/6, 65538*1/6 },

-    /* blue */

-    {    65538*1/13,65538*3/13,65538*9/13 },

-};

+		    dst[x] = pix;

+		}

+	    }

+	} else {

+

+	    for (h = height; h > 0; h--, srcLine += 3*src_pitch, dstLine += pitch) {

+		int x;

+		unsigned char *src = srcLine;

+		unsigned int *dst = (unsigned int *) dstLine;

+

+		for (x = 0; x < width; x++, src += 1) {

+		    unsigned int  pix;

+

+		    pix = ((unsigned int)src[src_pitch * 2] << 16) |

+			  ((unsigned int)src[src_pitch]     <<  8) |

+			  ((unsigned int)src[0]                  ) |

+			  ((unsigned int)src[src_pitch]     << 24) ;