Commit 32a7d87050bf891d476892d441a56921eda299b0
2013-08-17T22:19:21
[base] Clean up BBox_Conic_Check. * src/base/ftbbox.c (BBox_Conic_Check): Remove redundant checks for extremum at the segment ends, which are already within the bbox. Slightly modify calculations.
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diff --git a/ChangeLog b/ChangeLog
index 0098354..c79b8c0 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2013-08-17 Alexei Podtelezhnikov <apodtele@gmail.com>
+
+ [base] Clean up BBox_Conic_Check.
+
+ * src/base/ftbbox.c (BBox_Conic_Check): Remove redundant checks for
+ extremum at the segment ends, which are already within the bbox.
+ Slightly modify calculations.
+
2013-08-15 Alexei Podtelezhnikov <apodtele@gmail.com>
[base] Finish experimental (disabled) BBox_Cubic_Check implementation.
diff --git a/src/base/ftbbox.c b/src/base/ftbbox.c
index 3fe0a7d..c4bd027 100644
--- a/src/base/ftbbox.c
+++ b/src/base/ftbbox.c
@@ -108,30 +108,19 @@
FT_Pos* min,
FT_Pos* max )
{
- if ( y1 <= y3 && y2 == y1 ) /* flat arc */
- goto Suite;
-
- if ( y1 < y3 )
- {
- if ( y2 >= y1 && y2 <= y3 ) /* ascending arc */
- goto Suite;
- }
- else
- {
- if ( y2 >= y3 && y2 <= y1 ) /* descending arc */
- {
- y2 = y1;
- y1 = y3;
- y3 = y2;
- goto Suite;
- }
- }
-
- y1 = y3 = y1 - FT_MulDiv( y2 - y1, y2 - y1, y1 - 2*y2 + y3 );
-
- Suite:
- if ( y1 < *min ) *min = y1;
- if ( y3 > *max ) *max = y3;
+ /* This function is only called when a control off-point is outside */
+ /* the bbox. This also means there must be a local extremum within */
+ /* the segment with the value of (y1*y3 - y2*y2)/(y1 - 2*y2 + y3). */
+ /* Offsetting from the closest point to the extermum, y2, we get */
+
+ y1 -= y2;
+ y3 -= y2;
+ y2 += FT_MulDiv( y1, y3, y1 + y3 );
+
+ if ( y2 < *min )
+ *min = y2;
+ if ( y2 > *max )
+ *max = y2;
}