Commit 54c5ad5c9215feca69614565be7ec2030ee46cfb
2021-02-10T19:24:13
[sfnt] Implement 'COLR' v1 sweep gradients. * freetype.h (FT_PaintSweepGradient): Add `FT_PaintSweepGradient` to represent a 'COLR' v1 sweep gradient. Update format. (FT_PaintFormat): Update shifted paint formats. Sync with spec. * sfnt/ttcolr.c (read_paint): Logic to parse sweep gradients. Fix struct access in radial gradient implementation.
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diff --git a/ChangeLog b/ChangeLog
index d310fac..62400f4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,15 @@
+2021-02-10 Dominik Röttsches <drott@chromium.org>
+
+ [sfnt] Implement 'COLR' v1 sweep gradients.
+
+ * freetype.h (FT_PaintSweepGradient): Add `FT_PaintSweepGradient` to
+ represent a 'COLR' v1 sweep gradient.
+ Update format.
+ (FT_PaintFormat): Update shifted paint formats.
+ Sync with spec.
+ * sfnt/ttcolr.c (read_paint): Logic to parse sweep gradients.
+ Fix struct access in radial gradient implementation.
+
2021-02-09 Dominik Röttsches <drott@chromium.org>
[sfnt] Provide optional root transform for 'COLR' v1 glyph graph.
diff --git a/include/freetype/freetype.h b/include/freetype/freetype.h
index 5d8e8dc..c157796 100644
--- a/include/freetype/freetype.h
+++ b/include/freetype/freetype.h
@@ -4235,14 +4235,15 @@ FT_BEGIN_HEADER
FT_COLR_PAINTFORMAT_SOLID = 2,
FT_COLR_PAINTFORMAT_LINEAR_GRADIENT = 3,
FT_COLR_PAINTFORMAT_RADIAL_GRADIENT = 4,
- FT_COLR_PAINTFORMAT_GLYPH = 5,
- FT_COLR_PAINTFORMAT_COLR_GLYPH = 6,
- FT_COLR_PAINTFORMAT_TRANSFORMED = 7,
- FT_COLR_PAINTFORMAT_TRANSLATE = 8,
- FT_COLR_PAINTFORMAT_ROTATE = 9,
- FT_COLR_PAINTFORMAT_SKEW = 10,
- FT_COLR_PAINTFORMAT_COMPOSITE = 11,
- FT_COLR_PAINT_FORMAT_MAX = 12,
+ FT_COLR_PAINTFORMAT_SWEEP_GRADIENT = 5,
+ FT_COLR_PAINTFORMAT_GLYPH = 6,
+ FT_COLR_PAINTFORMAT_COLR_GLYPH = 7,
+ FT_COLR_PAINTFORMAT_TRANSFORMED = 8,
+ FT_COLR_PAINTFORMAT_TRANSLATE = 9,
+ FT_COLR_PAINTFORMAT_ROTATE = 10,
+ FT_COLR_PAINTFORMAT_SKEW = 11,
+ FT_COLR_PAINTFORMAT_COMPOSITE = 12,
+ FT_COLR_PAINT_FORMAT_MAX = 13,
FT_COLR_PAINTFORMAT_UNSUPPORTED = 255
} FT_PaintFormat;
@@ -4611,7 +4612,6 @@ FT_BEGIN_HEADER
{
FT_ColorLine colorline;
- /* TODO: Potentially expose those as x0, y0 etc. */
FT_Vector c0;
FT_UShort r0;
FT_Vector c1;
@@ -4623,6 +4623,48 @@ FT_BEGIN_HEADER
/**************************************************************************
*
* @struct:
+ * FT_PaintSweepGradient
+ *
+ * @description:
+ * A structure representing a `PaintSweepGradient` value of the 'COLR'
+ * v1 extensions, see
+ * 'https://github.com/googlefonts/colr-gradients-spec'. The glyph
+ * layer filled with this paint is drawn filled with a sweep gradient
+ * from `start_angle` to `end_angle`.
+ *
+ * @fields:
+ * colorline ::
+ * The @FT_ColorLine information for this paint, i.e., the list of
+ * color stops along the gradient.
+ *
+ * center ::
+ * The center of the sweep gradient (in font units).
+ *
+ * start_angle ::
+ * The start angle of the sweep gradient, in 16.16 fixed point format
+ * specifying degrees. Values are given counter-clockwise, starting
+ * from the (positive) y~axis.
+ *
+ * end_angle ::
+ * The end angle of the sweep gradient, in 16.16 fixed point format
+ * specifying degrees. Values are given counter-clockwise, starting
+ * from the (positive) y~axis.
+ *
+ */
+ typedef struct FT_PaintSweepGradient_
+ {
+ FT_ColorLine colorline;
+
+ FT_Vector center;
+ FT_Fixed start_angle;
+ FT_Fixed end_angle;
+
+ } FT_PaintSweepGradient;
+
+
+ /**************************************************************************
+ *
+ * @struct:
* FT_PaintGlyph
*
* @description:
@@ -4853,6 +4895,7 @@ FT_BEGIN_HEADER
* * @FT_PaintSolid
* * @FT_PaintLinearGradient
* * @FT_PaintRadialGradient
+ * * @FT_PaintSweepGradient
* * @FT_PaintTransformed
* * @FT_PaintTranslate
* * @FT_PaintRotate
@@ -4871,6 +4914,7 @@ FT_BEGIN_HEADER
FT_PaintSolid solid;
FT_PaintLinearGradient linear_gradient;
FT_PaintRadialGradient radial_gradient;
+ FT_PaintSweepGradient sweep_gradient;
FT_PaintTransformed transformed;
FT_PaintTranslate translate;
FT_PaintRotate rotate;
diff --git a/src/sfnt/ttcolr.c b/src/sfnt/ttcolr.c
index 6ba3a63..b90e35b 100644
--- a/src/sfnt/ttcolr.c
+++ b/src/sfnt/ttcolr.c
@@ -441,7 +441,7 @@
if ( !read_color_line( paint_base,
color_line_offset,
- &apaint->u.linear_gradient.colorline ) )
+ &apaint->u.radial_gradient.colorline ) )
return 0;
/* skip VarIdx entries */
@@ -462,6 +462,28 @@
FT_NEXT_ULONG ( p );
}
+ else if ( apaint->format == FT_COLR_PAINTFORMAT_SWEEP_GRADIENT )
+ {
+ FT_ULong color_line_offset = color_line_offset = FT_NEXT_OFF3( p );
+
+
+ if ( !read_color_line( paint_base,
+ color_line_offset,
+ &apaint->u.sweep_gradient.colorline ) )
+ return 0;
+
+ /* skip VarIdx entries */
+ apaint->u.sweep_gradient.center.x = FT_NEXT_SHORT ( p );
+ FT_NEXT_ULONG ( p );
+ apaint->u.sweep_gradient.center.y = FT_NEXT_SHORT ( p );
+ FT_NEXT_ULONG ( p );
+
+ apaint->u.sweep_gradient.start_angle = FT_NEXT_LONG( p );
+ FT_NEXT_ULONG ( p );
+ apaint->u.sweep_gradient.end_angle = FT_NEXT_LONG( p );
+ FT_NEXT_ULONG ( p );
+ }
+
else if ( apaint->format == FT_COLR_PAINTFORMAT_TRANSFORMED )
{
FT_UInt32 paint_offset;
@@ -842,7 +864,7 @@
/* `x_scale` and `y_scale` are in 26.6 format, representing the scale
* factor to get from font units to requested size. However, expected
- * return values are in 16.16, so we shift accordingly with rounding.
+ * return values are in 16.16, so we shift accordingly with rounding.
*/
ft_root_scale.xx = ( face->root.size->metrics.x_scale + 32 ) >> 6;
ft_root_scale.xy = 0;