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[freetype2] master da8e42897 2/2: [raster] Rearrange dropout control.
|
From: |
Werner Lemberg |
|
Subject: |
[freetype2] master da8e42897 2/2: [raster] Rearrange dropout control. |
|
Date: |
Tue, 21 Nov 2023 00:56:54 -0500 (EST) |
branch: master
commit da8e4289776316bf2d13dc5fcb83def745ee3810
Author: Alexei Podtelezhnikov <apodtele@gmail.com>
Commit: Alexei Podtelezhnikov <apodtele@gmail.com>
[raster] Rearrange dropout control.
This reduces the code duplication.
* src/raster/ftraster.c (Function_Sweep_Span): Change signature.
(Vertical_Sweep_Drop, Horizontal_Sweep_Drop): Focus on pixel setting
and move duplicated the dropout control logic to...
(Draw_Sweep): ... this function and refactor.
(Vertical_Sweep_Span, Horizontal_Sweep_Span): Minor.
---
src/raster/ftraster.c | 375 +++++++++++++++++---------------------------------
1 file changed, 128 insertions(+), 247 deletions(-)
diff --git a/src/raster/ftraster.c b/src/raster/ftraster.c
index 3fc4c53f3..2a84aef3a 100644
--- a/src/raster/ftraster.c
+++ b/src/raster/ftraster.c
@@ -401,9 +401,7 @@
typedef void
Function_Sweep_Span( RAS_ARGS Int y,
FT_F26Dot6 x1,
- FT_F26Dot6 x2,
- PProfile left,
- PProfile right );
+ FT_F26Dot6 x2 );
typedef void
Function_Sweep_Step( RAS_ARG );
@@ -1989,15 +1987,11 @@
static void
Vertical_Sweep_Span( RAS_ARGS Int y,
FT_F26Dot6 x1,
- FT_F26Dot6 x2,
- PProfile left,
- PProfile right )
+ FT_F26Dot6 x2 )
{
Int e1, e2;
FT_UNUSED( y );
- FT_UNUSED( left );
- FT_UNUSED( right );
FT_TRACE7(( " y=%d x=[% .*f;% .*f]",
@@ -2054,137 +2048,38 @@
static void
Vertical_Sweep_Drop( RAS_ARGS Int y,
FT_F26Dot6 x1,
- FT_F26Dot6 x2,
- PProfile left,
- PProfile right )
+ FT_F26Dot6 x2 )
{
- Long e1, e2, pxl;
- Int c1, f1;
+ Int e1 = (Int)TRUNC( x1 );
+ Int e2 = (Int)TRUNC( x2 );
+ Int c1, f1;
FT_UNUSED( y );
- FT_TRACE7(( " y=%d x=[% .*f;% .*f]",
- y,
- ras.precision_bits, (double)x1 / (double)ras.precision,
- ras.precision_bits, (double)x2 / (double)ras.precision ));
+ /* undocumented but confirmed: If the drop-out would result in a */
+ /* pixel outside of the bounding box, use the pixel inside of the */
+ /* bounding box instead */
+ if ( e1 < 0 || e1 > ras.bRight )
+ e1 = e2;
- /* Drop-out control */
-
- /* e2 x2 x1 e1 */
- /* */
- /* ^ | */
- /* | | */
- /* +-------------+---------------------+------------+ */
- /* | | */
- /* | v */
- /* */
- /* pixel contour contour pixel */
- /* center center */
-
- /* drop-out mode scan conversion rules (OpenType specs) */
- /* ------------------------------------------------------- */
- /* bit 0 exclude stubs if set */
- /* bit 1 ignore drop-outs if set */
- /* bit 2 smart rounding if set */
-
- e1 = CEILING( x1 );
- e2 = FLOOR ( x2 );
- pxl = e1;
-
- if ( e1 > e2 )
+ /* otherwise check that the other pixel isn't set */
+ else if ( e2 >=0 && e2 <= ras.bRight )
{
- Int dropOutControl = left->flags & 7;
-
-
- if ( e1 == e2 + ras.precision )
- {
- /* Drop-out Control Rules #4 and #6 */
-
- /* The specification neither provides an exact definition */
- /* of a `stub' nor gives exact rules to exclude them. */
- /* */
- /* Here the constraints we use to recognize a stub. */
- /* */
- /* upper stub: */
- /* */
- /* - P_Left and P_Right are in the same contour */
- /* - P_Right is the successor of P_Left in that contour */
- /* - y is the top of P_Left and P_Right */
- /* */
- /* lower stub: */
- /* */
- /* - P_Left and P_Right are in the same contour */
- /* - P_Left is the successor of P_Right in that contour */
- /* - y is the bottom of P_Left */
- /* */
- /* We draw a stub if the following constraints are met. */
- /* */
- /* - for an upper or lower stub, there is top or bottom */
- /* overshoot, respectively */
- /* - the covered interval is greater or equal to a half */
- /* pixel */
-
- if ( dropOutControl & 1 )
- {
- /* rightmost stub test */
- if ( left->next == right &&
- left->height == 1 &&
- !( left->flags & Overshoot_Top &&
- x2 - x1 >= ras.precision_half ) )
- goto Exit;
-
- /* leftmost stub test */
- if ( right->next == left &&
- left->offset == 0 &&
- !( left->flags & Overshoot_Bottom &&
- x2 - x1 >= ras.precision_half ) )
- goto Exit;
- }
+ c1 = (Int)( e2 >> 3 );
+ f1 = (Int)( e2 & 7 );
- if ( dropOutControl & 4 )
- pxl = SMART( x1, x2 );
- else
- pxl = e2;
-
- /* undocumented but confirmed: If the drop-out would result in a */
- /* pixel outside of the bounding box, use the pixel inside of the */
- /* bounding box instead */
- if ( pxl < 0 )
- pxl = e1;
- else if ( TRUNC( pxl ) > ras.bRight )
- pxl = e2;
-
- /* check that the other pixel isn't set */
- e1 = ( pxl == e1 ) ? e2 : e1;
-
- e1 = TRUNC( e1 );
-
- c1 = (Int)( e1 >> 3 );
- f1 = (Int)( e1 & 7 );
-
- if ( e1 >= 0 && e1 <= ras.bRight &&
- ras.bLine[c1] & ( 0x80 >> f1 ) )
- goto Exit;
- }
- else
- goto Exit;
+ if ( ras.bLine[c1] & ( 0x80 >> f1 ) )
+ return;
}
- e1 = TRUNC( pxl );
-
if ( e1 >= 0 && e1 <= ras.bRight )
{
- FT_TRACE7(( " -> x=%ld", e1 ));
-
c1 = (Int)( e1 >> 3 );
f1 = (Int)( e1 & 7 );
ras.bLine[c1] |= 0x80 >> f1;
}
-
- Exit:
- FT_TRACE7(( " dropout=%d\n", left->flags & 7 ));
}
@@ -2218,15 +2113,10 @@
static void
Horizontal_Sweep_Span( RAS_ARGS Int y,
FT_F26Dot6 x1,
- FT_F26Dot6 x2,
- PProfile left,
- PProfile right )
+ FT_F26Dot6 x2 )
{
Long e1, e2;
- FT_UNUSED( left );
- FT_UNUSED( right );
-
FT_TRACE7(( " x=%d y=[% .*f;% .*f]",
y,
@@ -2290,103 +2180,37 @@
static void
Horizontal_Sweep_Drop( RAS_ARGS Int y,
FT_F26Dot6 x1,
- FT_F26Dot6 x2,
- PProfile left,
- PProfile right )
+ FT_F26Dot6 x2 )
{
- Long e1, e2, pxl;
+ Int e1 = (Int)TRUNC( x1 );
+ Int e2 = (Int)TRUNC( x2 );
PByte bits;
Int f1;
- FT_TRACE7(( " x=%d y=[% .*f;% .*f]",
- y,
- ras.precision_bits, (double)x1 / (double)ras.precision,
- ras.precision_bits, (double)x2 / (double)ras.precision ));
-
- /* During the horizontal sweep, we only take care of drop-outs */
-
- /* e1 + <-- pixel center */
- /* | */
- /* x1 ---+--> <-- contour */
- /* | */
- /* | */
- /* x2 <--+--- <-- contour */
- /* | */
- /* | */
- /* e2 + <-- pixel center */
+ /* undocumented but confirmed: If the drop-out would result in a */
+ /* pixel outside of the bounding box, use the pixel inside of the */
+ /* bounding box instead */
+ if ( e1 < 0 || e1 > ras.bTop )
+ e1 = e2;
- e1 = CEILING( x1 );
- e2 = FLOOR ( x2 );
- pxl = e1;
-
- if ( e1 > e2 )
+ /* otherwise check that the other pixel isn't set */
+ else if ( e2 >=0 && e2 <= ras.bTop )
{
- Int dropOutControl = left->flags & 7;
-
-
- if ( e1 == e2 + ras.precision )
- {
- if ( dropOutControl & 1 )
- {
- /* rightmost stub test */
- if ( left->next == right &&
- left->height == 1 &&
- !( left->flags & Overshoot_Top &&
- x2 - x1 >= ras.precision_half ) )
- goto Exit;
-
- /* leftmost stub test */
- if ( right->next == left &&
- left->offset == 0 &&
- !( left->flags & Overshoot_Bottom &&
- x2 - x1 >= ras.precision_half ) )
- goto Exit;
- }
-
- if ( dropOutControl & 4 )
- pxl = SMART( x1, x2 );
- else
- pxl = e2;
-
- /* undocumented but confirmed: If the drop-out would result in a */
- /* pixel outside of the bounding box, use the pixel inside of the */
- /* bounding box instead */
- if ( pxl < 0 )
- pxl = e1;
- else if ( TRUNC( pxl ) > ras.bTop )
- pxl = e2;
+ bits = ras.bOrigin + ( y >> 3 ) - e2 * ras.bPitch;
+ f1 = 0x80 >> ( y & 7 );
- /* check that the other pixel isn't set */
- e1 = ( pxl == e1 ) ? e2 : e1;
-
- e1 = TRUNC( e1 );
-
- bits = ras.bOrigin + ( y >> 3 ) - e1 * ras.bPitch;
- f1 = 0x80 >> ( y & 7 );
-
- if ( e1 >= 0 && e1 <= ras.bTop &&
- *bits & f1 )
- goto Exit;
- }
- else
- goto Exit;
+ if ( *bits & f1 )
+ return;
}
- e1 = TRUNC( pxl );
-
if ( e1 >= 0 && e1 <= ras.bTop )
{
- FT_TRACE7(( " -> y=%ld", e1 ));
-
bits = ras.bOrigin + ( y >> 3 ) - e1 * ras.bPitch;
f1 = 0x80 >> ( y & 7 );
- bits[0] |= f1;
+ *bits |= f1;
}
-
- Exit:
- FT_TRACE7(( " dropout=%d\n", left->flags & 7 ));
}
@@ -2477,37 +2301,120 @@
x2 = xs;
}
- /* if bottom ceiling exceeds top floor, it is a drop-out */
- if ( CEILING( x1 ) > FLOOR( x2 ) )
+ if ( CEILING( x1 ) <= FLOOR( x2 ) )
+ ras.Proc_Sweep_Span( RAS_VARS y, x1, x2 );
+
+ /* otherwise, bottom ceiling > top floor, it is a drop-out */
+ else
{
Int dropOutControl = P_Left->flags & 7;
+ /* Drop-out control */
+
+ /* e2 x2 x1 e1 */
+ /* */
+ /* ^ | */
+ /* | | */
+ /* +-------------+---------------------+------------+ */
+ /* | | */
+ /* | v */
+ /* */
+ /* pixel contour contour pixel */
+ /* center center */
+
+ /* drop-out mode scan conversion rules (OpenType specs) */
+ /* ------------------------------------------------------- */
+ /* bit 0 exclude stubs if set */
+ /* bit 1 ignore drop-outs if set */
+ /* bit 2 smart rounding if set */
+
if ( dropOutControl & 2 )
goto Next_Pair;
- P_Left ->X = x1;
- P_Right->X = x2;
+ /* The specification neither provides an exact definition */
+ /* of a `stub' nor gives exact rules to exclude them. */
+ /* */
+ /* Here the constraints we use to recognize a stub. */
+ /* */
+ /* upper stub: */
+ /* */
+ /* - P_Left and P_Right are in the same contour */
+ /* - P_Right is the successor of P_Left in that contour */
+ /* - y is the top of P_Left and P_Right */
+ /* */
+ /* lower stub: */
+ /* */
+ /* - P_Left and P_Right are in the same contour */
+ /* - P_Left is the successor of P_Right in that contour */
+ /* - y is the bottom of P_Left */
+ /* */
+ /* We draw a stub if the following constraints are met. */
+ /* */
+ /* - for an upper or lower stub, there is top or bottom */
+ /* overshoot, respectively */
+ /* - the covered interval is greater or equal to a half */
+ /* pixel */
+
+ if ( dropOutControl & 1 )
+ {
+ /* rightmost stub test */
+ if ( P_Left->next == P_Right &&
+ P_Left->height == 1 &&
+ !( P_Left->flags & Overshoot_Top &&
+ x2 - x1 >= ras.precision_half ) )
+ goto Next_Pair;
+
+ /* leftmost stub test */
+ if ( P_Right->next == P_Left &&
+ P_Left->offset == 0 &&
+ !( P_Left->flags & Overshoot_Bottom &&
+ x2 - x1 >= ras.precision_half ) )
+ goto Next_Pair;
+ }
+
+ /* select the pixel to set and the other pixel */
+ if ( dropOutControl & 4 )
+ {
+ x2 = SMART( x1, x2 );
+ x1 = x1 > x2 ? x2 + ras.precision : x2 - ras.precision;
+ }
+ else
+ {
+ x2 = FLOOR ( x2 );
+ x1 = CEILING( x1 );
+ }
+
+ P_Left ->X = x2;
+ P_Right->X = x1;
/* mark profile for drop-out processing */
P_Left->flags |= Dropout;
dropouts++;
}
- else
- ras.Proc_Sweep_Span( RAS_VARS y, x1, x2, P_Left, P_Right );
Next_Pair:
P_Left = P_Left->link;
P_Right = P_Right->link;
}
- /* handle drop-outs _after_ the span drawing -- */
- /* drop-out processing has been moved out of the loop */
- /* for performance tuning */
- if ( dropouts > 0 )
- goto Scan_DropOuts;
+ /* handle drop-outs _after_ the span drawing */
+ P_Left = draw_left;
+ P_Right = draw_right;
+
+ while ( dropouts && P_Left && P_Right )
+ {
+ if ( P_Left->flags & Dropout )
+ {
+ ras.Proc_Sweep_Drop( RAS_VARS y, P_Left->X, P_Right->X );
- Next_Line:
+ P_Left->flags &= ~Dropout;
+ dropouts--;
+ }
+
+ P_Left = P_Left->link;
+ P_Right = P_Right->link;
+ }
ras.Proc_Sweep_Step( RAS_VAR );
@@ -2518,32 +2425,6 @@
}
return SUCCESS;
-
- Scan_DropOuts:
-
- P_Left = draw_left;
- P_Right = draw_right;
-
- while ( P_Left && P_Right )
- {
- if ( P_Left->flags & Dropout )
- {
- P_Left->flags &= ~Dropout;
-#if 0
- dropouts--; /* -- this is useful when debugging only */
-#endif
- ras.Proc_Sweep_Drop( RAS_VARS y,
- P_Left->X,
- P_Right->X,
- P_Left,
- P_Right );
- }
-
- P_Left = P_Left->link;
- P_Right = P_Right->link;
- }
-
- goto Next_Line;
}
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