Attachment 19362 Details for Bug 10301 – Fallback to cairo lcd filtering if freetype cannot.

[patch] Fallback to cairo lcd filtering if freetype cannot.

fix_lcd_filtering.patch (text/plain), 13.55 KB, created by Nicolaus L Hepler on 2008-10-03 17:24:36 UTC

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Creator: Nicolaus L Hepler

Created: 2008-10-03 17:24:36 UTC

Size: 13.55 KB

patch

obsolete

>diff --git a/src/cairo-ft-font.c b/src/cairo-ft-font.c
>index 1ad7145..8887fc0 100644
>--- a/src/cairo-ft-font.c
>+++ b/src/cairo-ft-font.c
>@@ -180,6 +180,29 @@ typedef struct _cairo_ft_unscaled_font_map {
>     int num_open_faces;
> } cairo_ft_unscaled_font_map_t;
> 
>+static cairo_bool_t FT_CAN_LCD_FILTER = FALSE;
>+
>+static cairo_bool_t
>+_ft_can_lcd_filter (void)
>+{
>+#if HAVE_FT_LIBRARY_SETLCDFILTER
>+    FT_Library library;
>+    FT_Error fterror;
>+
>+    FT_Init_FreeType(&library);
>+    fterror = FT_Library_SetLcdFilter(library, FT_LCD_FILTER_DEFAULT);
>+
>+    if (fterror != FT_Err_Unimplemented_Feature)
>+	return TRUE;
>+    else
>+        return FALSE;
>+
>+    FT_Done_FreeType(library);
>+#else
>+    return FALSE;
>+#endif
>+}
>+
> static cairo_ft_unscaled_font_map_t *cairo_ft_unscaled_font_map = NULL;
> 
> static void
>@@ -1042,6 +1065,24 @@ _fill_xrender_bitmap(FT_Bitmap      *target,
> }
> 
> 
>+/* 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 },
>+#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 },
>+};
>+
> /* Fills in val->image with an image surface created from @bitmap
>  */
> static cairo_status_t
>@@ -1053,7 +1094,7 @@ _get_bitmap_surface (FT_Bitmap		     *bitmap,
>     int width, height, stride;
>     unsigned char *data;
>     int format = CAIRO_FORMAT_A8;
>-    cairo_image_surface_t *image;
>+    cairo_bool_t subpixel = FALSE;
> 
>     width = bitmap->width;
>     height = bitmap->rows;
>@@ -1110,7 +1151,7 @@ _get_bitmap_surface (FT_Bitmap		     *bitmap,
>     case FT_PIXEL_MODE_LCD:
>     case FT_PIXEL_MODE_LCD_V:
>     case FT_PIXEL_MODE_GRAY:
>-        if (font_options->antialias != CAIRO_ANTIALIAS_SUBPIXEL) {
>+	if (font_options->antialias != CAIRO_ANTIALIAS_SUBPIXEL) {
> 	    stride = bitmap->pitch;
> 	    if (own_buffer) {
> 		data = bitmap->buffer;
>@@ -1121,17 +1162,114 @@ _get_bitmap_surface (FT_Bitmap		     *bitmap,
> 
> 		memcpy (data, bitmap->buffer, stride * height);
> 	    }
>-	    format = CAIRO_FORMAT_A8;
>+		format = CAIRO_FORMAT_A8;
> 	} else {
>-	    /* if we get there, the  data from the source bitmap
>-	     * really comes from _fill_xrender_bitmap, and is
>-	     * made of 32-bit ARGB or ABGR values */
>-	    assert (own_buffer != 0);
>-	    assert (bitmap->pixel_mode != FT_PIXEL_MODE_GRAY);
>+	FT_CAN_LCD_FILTER = _ft_can_lcd_filter();
>+            if (FT_CAN_LCD_FILTER) {
>+		/* if we get there, the  data from the source bitmap
>+		 * really comes from _fill_xrender_bitmap, and is
>+		 * made of 32-bit ARGB or ABGR values */
>+		assert (own_buffer != 0);
>+		assert (bitmap->pixel_mode != FT_PIXEL_MODE_GRAY);
> 
>-	    data = bitmap->buffer;
>-	    stride = bitmap->pitch;
>-	    format = CAIRO_FORMAT_ARGB32;
>+		data = bitmap->buffer;
>+		stride = bitmap->pitch;
>+		format = CAIRO_FORMAT_ARGB32;
>+            } else {
>+		int		    x, y;
>+		unsigned char   *in_line, *out_line, *in;
>+		unsigned int    *out;
>+		unsigned int    red, green, blue;
>+		int		    rf, gf, bf;
>+		int		    s;
>+		int		    o, os;
>+		unsigned char   *data_rgba;
>+		unsigned int    width_rgba, stride_rgba;
>+		int		    vmul = 1;
>+		int		    hmul = 1;
>+
>+		switch (font_options->subpixel_order) {
>+		case CAIRO_SUBPIXEL_ORDER_DEFAULT:
>+		case CAIRO_SUBPIXEL_ORDER_RGB:
>+		case CAIRO_SUBPIXEL_ORDER_BGR:
>+		default:
>+		    width /= 3;
>+		    hmul = 3;
>+		    break;
>+		case CAIRO_SUBPIXEL_ORDER_VRGB:
>+		case CAIRO_SUBPIXEL_ORDER_VBGR:
>+		    vmul = 3;
>+		    height /= 3;
>+		    break;
>+		}
>+		/*
>+		 * Filter the glyph to soften the color fringes
>+		 */
>+		width_rgba = width;
>+		stride = bitmap->pitch;
>+		stride_rgba = (width_rgba * 4 + 3) & ~3;
>+		data_rgba = calloc (stride_rgba, height);
>+		if (data_rgba == NULL) {
>+		    if (own_buffer)
>+			free (bitmap->buffer);
>+		    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
>+		}
>+
>+		os = 1;
>+		switch (font_options->subpixel_order) {
>+		case CAIRO_SUBPIXEL_ORDER_VRGB:
>+		    os = stride;
>+		case CAIRO_SUBPIXEL_ORDER_DEFAULT:
>+		case CAIRO_SUBPIXEL_ORDER_RGB:
>+		default:
>+		    rf = 0;
>+		    gf = 1;
>+		    bf = 2;
>+		    break;
>+		case CAIRO_SUBPIXEL_ORDER_VBGR:
>+		    os = stride;
>+		case CAIRO_SUBPIXEL_ORDER_BGR:
>+		    bf = 0;
>+		    gf = 1;
>+		    rf = 2;
>+		    break;
>+		}
>+		in_line = bitmap->buffer;
>+		out_line = data_rgba;
>+		for (y = 0; y < height; y++)
>+		{
>+		    in = in_line;
>+		    out = (unsigned int *) out_line;
>+		    in_line += stride * vmul;
>+		    out_line += stride_rgba;
>+		    for (x = 0; x < width * hmul; x += hmul)
>+		    {
>+			red = green = blue = 0;
>+			o = 0;
>+			for (s = 0; s < 3; s++)
>+			{
>+			    red += filters[rf][s]*in[x+o];
>+			    green += filters[gf][s]*in[x+o];
>+			    blue += filters[bf][s]*in[x+o];
>+			    o += os;
>+			}
>+			red = red / 65536;
>+			green = green / 65536;
>+			blue = blue / 65536;
>+			*out++ = (green << 24) | (red << 16) | (green << 8) | blue;
>+		    }
>+		}
>+
>+		/* Images here are stored in native format. The
>+		 * backend must convert to its own format as needed
>+		 */
>+		if (own_buffer)
>+		free (bitmap->buffer);
>+		data = data_rgba;
>+		stride = stride_rgba;
>+		format = CAIRO_FORMAT_ARGB32;
>+	    }
>+	    subpixel = TRUE;
> 	}
> 	break;
>     case FT_PIXEL_MODE_GRAY2:
>@@ -1143,20 +1281,19 @@ _get_bitmap_surface (FT_Bitmap		     *bitmap,
> 	return _cairo_error (CAIRO_STATUS_NO_MEMORY);
>     }
> 
>-    /* XXX */
>-    *surface = image = (cairo_image_surface_t *)
>+    *surface = (cairo_image_surface_t *)
> 	cairo_image_surface_create_for_data (data,
> 					     format,
> 					     width, height, stride);
>-    if (image->base.status) {
>+    if ((*surface)->base.status) {
> 	free (data);
> 	return (*surface)->base.status;
>     }
> 
>-    if (font_options->antialias == CAIRO_ANTIALIAS_SUBPIXEL)
>-	pixman_image_set_component_alpha (image->pixman_image, TRUE);
>+    if (subpixel)
>+	pixman_image_set_component_alpha ((*surface)->pixman_image, TRUE);
> 
>-    _cairo_image_surface_assume_ownership_of_data (image);
>+    _cairo_image_surface_assume_ownership_of_data ((*surface));
> 
>     return CAIRO_STATUS_SUCCESS;
> }
>@@ -1188,6 +1325,7 @@ _render_glyph_outline (FT_Face                    face,
>     FT_Bitmap bitmap;
>     FT_BBox cbox;
>     unsigned int width, height;
>+    double device_offset_left, device_offset_top;
>     cairo_status_t status;
>     FT_Error fterror;
>     FT_Library library = glyphslot->library;
>@@ -1199,18 +1337,6 @@ _render_glyph_outline (FT_Face                    face,
> 	break;
> 
>     case CAIRO_ANTIALIAS_SUBPIXEL:
>-	switch (font_options->subpixel_order) {
>-	    case CAIRO_SUBPIXEL_ORDER_DEFAULT:
>-	    case CAIRO_SUBPIXEL_ORDER_RGB:
>-	    case CAIRO_SUBPIXEL_ORDER_BGR:
>-		render_mode = FT_RENDER_MODE_LCD;
>-		break;
>-
>-	    case CAIRO_SUBPIXEL_ORDER_VRGB:
>-	    case CAIRO_SUBPIXEL_ORDER_VBGR:
>-		render_mode = FT_RENDER_MODE_LCD_V;
>-		break;
>-	}
> 
> 	switch (font_options->lcd_filter) {
> 	case CAIRO_LCD_FILTER_NONE:
>@@ -1228,6 +1354,27 @@ _render_glyph_outline (FT_Face                    face,
> 	    break;
> 	}
> 
>+#if HAVE_FT_LIBRARY_SETLCDFILTER
>+	fterror = FT_Library_SetLcdFilter (library, lcd_filter);
>+	if(fterror != FT_Err_Unimplemented_Feature)
>+	    FT_CAN_LCD_FILTER = TRUE;
>+#endif
>+
>+        if (FT_CAN_LCD_FILTER) {
>+	    switch (font_options->subpixel_order) {
>+		case CAIRO_SUBPIXEL_ORDER_DEFAULT:
>+		case CAIRO_SUBPIXEL_ORDER_RGB:
>+		case CAIRO_SUBPIXEL_ORDER_BGR:
>+		    render_mode = FT_RENDER_MODE_LCD;
>+		    break;
>+
>+		case CAIRO_SUBPIXEL_ORDER_VRGB:
>+		case CAIRO_SUBPIXEL_ORDER_VBGR:
>+		    render_mode = FT_RENDER_MODE_LCD_V;
>+		    break;
>+	    }
>+	}
>+
> 	break;
> 
>     case CAIRO_ANTIALIAS_DEFAULT:
>@@ -1268,75 +1415,126 @@ _render_glyph_outline (FT_Face                    face,
> 	    cairo_image_surface_create_for_data (NULL, format, 0, 0, 0);
> 	if ((*surface)->base.status)
> 	    return (*surface)->base.status;
>-    } else  {
> 
>-	int bitmap_size;
>+    } else {
> 
>-	switch (render_mode) {
>-	case FT_RENDER_MODE_LCD:
>-	    if (font_options->subpixel_order == CAIRO_SUBPIXEL_ORDER_BGR) {
>-		rgba = FC_RGBA_BGR;
>-	    } else {
>-		rgba = FC_RGBA_RGB;
>-	    }
>-	    break;
>-	case FT_RENDER_MODE_LCD_V:
>-	    if (font_options->subpixel_order == CAIRO_SUBPIXEL_ORDER_VBGR) {
>-		rgba = FC_RGBA_VBGR;
>-	    } else {
>-		rgba = FC_RGBA_VRGB;
>-	    }
>-	    break;
>-	case FT_RENDER_MODE_MONO:
>-	case FT_RENDER_MODE_LIGHT:
>-	case FT_RENDER_MODE_NORMAL:
>-	case FT_RENDER_MODE_MAX:
>-	default:
>-	    break;
>-	}
>+	if (FT_CAN_LCD_FILTER) {
> 
>-#if HAVE_FT_LIBRARY_SETLCDFILTER
>-	FT_Library_SetLcdFilter (library, lcd_filter);
>-#endif
>+	    int bitmap_size;
> 
>-	fterror = FT_Render_Glyph (face->glyph, render_mode);
>+	    switch (render_mode) {
>+	    case FT_RENDER_MODE_LCD:
>+		if (font_options->subpixel_order == CAIRO_SUBPIXEL_ORDER_BGR) {
>+		    rgba = FC_RGBA_BGR;
>+		} else {
>+		    rgba = FC_RGBA_RGB;
>+		}
>+		break;
>+	    case FT_RENDER_MODE_LCD_V:
>+		if (font_options->subpixel_order == CAIRO_SUBPIXEL_ORDER_VBGR) {
>+		    rgba = FC_RGBA_VBGR;
>+		} else {
>+		    rgba = FC_RGBA_VRGB;
>+		}
>+	        break;
>+	    case FT_RENDER_MODE_MONO:
>+	    case FT_RENDER_MODE_LIGHT:
>+	    case FT_RENDER_MODE_NORMAL:
>+	    case FT_RENDER_MODE_MAX:
>+	    default:
>+		break;
>+	    }
>+
>+	    fterror = FT_Render_Glyph (face->glyph, render_mode);
> 
> #if HAVE_FT_LIBRARY_SETLCDFILTER
>-	FT_Library_SetLcdFilter (library, FT_LCD_FILTER_NONE);
>+	    FT_Library_SetLcdFilter (library, FT_LCD_FILTER_NONE);
> #endif
> 
>-	if (fterror != 0)
>-	    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
>+	    if (fterror != 0)
>+		return _cairo_error (CAIRO_STATUS_NO_MEMORY);
> 
>-	bitmap_size = _compute_xrender_bitmap_size (&bitmap,
>+	    bitmap_size = _compute_xrender_bitmap_size (&bitmap,
> 						    face->glyph,
> 						    render_mode);
>-	if (bitmap_size < 0)
>-	    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
>+	    if (bitmap_size < 0)
>+		return _cairo_error (CAIRO_STATUS_NO_MEMORY);
> 
>-	bitmap.buffer = calloc (1, bitmap_size);
>-	if (bitmap.buffer == NULL)
>-	    return _cairo_error (CAIRO_STATUS_NO_MEMORY);
>+	    bitmap.buffer = calloc (1, bitmap_size);
>+	    if (bitmap.buffer == NULL)
>+		return _cairo_error (CAIRO_STATUS_NO_MEMORY);
> 
>-	_fill_xrender_bitmap (&bitmap, face->glyph, render_mode,
>+	    _fill_xrender_bitmap (&bitmap, face->glyph, render_mode,
> 			      (rgba == FC_RGBA_BGR || rgba == FC_RGBA_VBGR));
> 
>+	    device_offset_left = (double)-glyphslot->bitmap_left;
>+	    device_offset_top = (double)+glyphslot->bitmap_top;
>+
>+	} else {
>+
>+	    FT_Matrix matrix;
>+	    int hmul = 1;
>+	    int vmul = 1;
>+	    unsigned int stride;
>+
>+	    stride = (width * hmul + 3) & ~3;
>+
>+	    matrix.xx = matrix.yy = 0x10000L;
>+	    matrix.xy = matrix.yx = 0;
>+
>+	    switch (font_options->subpixel_order) {
>+	    case CAIRO_SUBPIXEL_ORDER_RGB:
>+	    case CAIRO_SUBPIXEL_ORDER_BGR:
>+	    case CAIRO_SUBPIXEL_ORDER_DEFAULT:
>+	    default:
>+		matrix.xx *= 3;
>+		hmul = 3;
>+		break;
>+	    case CAIRO_SUBPIXEL_ORDER_VRGB:
>+	    case CAIRO_SUBPIXEL_ORDER_VBGR:
>+		matrix.yy *= 3;
>+		vmul = 3;
>+		break;
>+	    }
>+	    FT_Outline_Transform (outline, &matrix);
>+
>+	    bitmap.pixel_mode = FT_PIXEL_MODE_GRAY;
>+	    bitmap.num_grays  = 256;
>+	    stride = (width * hmul + 3) & -4;
>+
>+	    bitmap.pitch = stride;
>+	    bitmap.width = width * hmul;
>+	    bitmap.rows = height * vmul;
>+	    bitmap.buffer = calloc (stride, bitmap.rows);
>+	    if (bitmap.buffer == NULL)
>+		return _cairo_error (CAIRO_STATUS_NO_MEMORY);
>+
>+	    FT_Outline_Translate (outline, -cbox.xMin*hmul, -cbox.yMin*vmul);
>+
>+	    if (FT_Outline_Get_Bitmap (glyphslot->library, outline, &bitmap) != 0) {
>+		free (bitmap.buffer);
>+		return _cairo_error (CAIRO_STATUS_NO_MEMORY);
>+	    }
>+
>+	    device_offset_left = floor (-(double) cbox.xMin / 64.0);
>+	    device_offset_top = floor (+(double) cbox.yMax / 64.0);
>+	}
>+
> 	/* Note:
> 	 * _get_bitmap_surface will free bitmap.buffer if there is an error
> 	 */
> 	status = _get_bitmap_surface (&bitmap, TRUE, font_options, surface);
> 	if (status)
> 	    return status;
>-
>-	/* Note: the font's coordinate system is upside down from ours, so the
>-	 * Y coordinate of the control box needs to be negated.  Moreover, device
>-	 * offsets are position of glyph origin relative to top left while xMin
>-	 * and yMax are offsets of top left relative to origin.  Another negation.
>-	 */
>-	cairo_surface_set_device_offset (&(*surface)->base,
>-					 (double)-glyphslot->bitmap_left,
>-					 (double)+glyphslot->bitmap_top);
>     }
>+    /* Note: the font's coordinate system is upside down from ours, so the
>+     * Y coordinate of the control box needs to be negated.  Moreover, device
>+     * offsets are position of glyph origin relative to top left while xMin
>+     * and yMax are offsets of top left relative to origin.  Another negation.
>+     */
>+    cairo_surface_set_device_offset (&(*surface)->base,
>+				     device_offset_left,
>+	    			     device_offset_top);
> 
>     return CAIRO_STATUS_SUCCESS;
> }
>@@ -1729,7 +1927,7 @@ _cairo_ft_options_merge (cairo_ft_options_t *options,
> 	    load_flags |= FT_LOAD_NO_HINTING;
> 	    break;
> 	case CAIRO_HINT_STYLE_SLIGHT:
>-	    load_target = FT_LOAD_TARGET_LIGHT;
>+	    load_target |= FT_LOAD_TARGET_LIGHT;
> 	    break;
> 	case CAIRO_HINT_STYLE_MEDIUM:
> 	    break;
>@@ -1740,11 +1938,11 @@ _cairo_ft_options_merge (cairo_ft_options_t *options,
> 		case CAIRO_SUBPIXEL_ORDER_DEFAULT:
> 		case CAIRO_SUBPIXEL_ORDER_RGB:
> 		case CAIRO_SUBPIXEL_ORDER_BGR:
>-		    load_target = FT_LOAD_TARGET_LCD;
>+		    load_target |= FT_LOAD_TARGET_LCD;
> 		    break;
> 		case CAIRO_SUBPIXEL_ORDER_VRGB:
> 		case CAIRO_SUBPIXEL_ORDER_VBGR:
>-		    load_target = FT_LOAD_TARGET_LCD_V;
>+		    load_target |= FT_LOAD_TARGET_LCD_V;
> 		break;
> 		}
> 	    }

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Attachments on bug 10301: 9148 | 10583 | 12910 | 12955 | 12971 | 12997 | 13825 | 17973 | 17975 | 19349 | 19362 | 21150 | 22299 | 22302 | 22336 | 36349 | 40431

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