Commit 134711d78a7d30fb6479c541e47aa989f2b84571
2008-05-06T21:19:29
* Make FTContour:FTContour comply with the FreeType specification and remove duplicate points in the Bézier curves. Fixes weird rendering errors with some fonts.
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diff --git a/src/FTContour.cpp b/src/FTContour.cpp
index 548322a..fee1e78 100644
--- a/src/FTContour.cpp
+++ b/src/FTContour.cpp
@@ -31,7 +31,7 @@
#include <math.h>
-static const float BEZIER_STEP_SIZE = 0.2f;
+static const unsigned int BEZIER_STEPS = 5;
void FTContour::AddPoint(FTPoint point)
@@ -64,9 +64,9 @@ void FTContour::AddBackPoint(FTPoint point)
void FTContour::evaluateQuadraticCurve(FTPoint A, FTPoint B, FTPoint C)
{
- for(unsigned int i = 0; i <= (1.0f / BEZIER_STEP_SIZE); i++)
+ for(unsigned int i = 1; i < BEZIER_STEPS; i++)
{
- float t = static_cast<float>(i) * BEZIER_STEP_SIZE;
+ float t = static_cast<float>(i) / BEZIER_STEPS;
FTPoint U = (1.0f - t) * A + t * B;
FTPoint V = (1.0f - t) * B + t * C;
@@ -75,11 +75,12 @@ void FTContour::evaluateQuadraticCurve(FTPoint A, FTPoint B, FTPoint C)
}
}
+
void FTContour::evaluateCubicCurve(FTPoint A, FTPoint B, FTPoint C, FTPoint D)
{
- for(unsigned int i = 0; i <= (1.0f / BEZIER_STEP_SIZE); i++)
+ for(unsigned int i = 0; i < BEZIER_STEPS; i++)
{
- float t = static_cast<float>(i) * BEZIER_STEP_SIZE;
+ float t = static_cast<float>(i) / BEZIER_STEPS;
FTPoint U = (1.0f - t) * A + t * B;
FTPoint V = (1.0f - t) * B + t * C;
@@ -156,54 +157,48 @@ void FTContour::outsetContour()
}
}
+
FTContour::FTContour(FT_Vector* contour, char* tags, unsigned int n)
{
- for(unsigned int i = 0; i < n; ++ i)
+ // See http://freetype.sourceforge.net/freetype2/docs/glyphs/glyphs-6.html
+ // for a full description of FreeType tags.
+ for(unsigned int i = 0; i < n; i++)
{
- if(tags[i] == FT_Curve_Tag_On || n < 2)
+ FTPoint cur(contour[i]);
+
+ // Only process point tags we know.
+ if(n < 2 || FT_CURVE_TAG(tags[i]) == FT_Curve_Tag_On)
{
- AddPoint(FTPoint(contour[i]));
- continue;
+ AddPoint(cur);
}
-
- FTPoint cur(contour[i]);
- FTPoint prev = (pointList.size() == 0 || i == 0)
- ? FTPoint(contour[n - 1])
- : pointList[pointList.size() - 1];
- FTPoint next = (i == n - 1)
- ? (pointList.size() == 0)
- ? FTPoint(contour[0])
- : pointList[0]
- : FTPoint(contour[i + 1]);
-
- if(tags[i] == FT_Curve_Tag_Conic)
+ else if(FT_CURVE_TAG(tags[i]) == FT_Curve_Tag_Conic)
{
- while(tags[(i == n - 1) ? 0 : i + 1] == FT_Curve_Tag_Conic)
+ // Previous point is either the real previous point (an "on"
+ // point), or the midpoint between the current one and the
+ // previous "conic off" point.
+ FTPoint prev(contour[(i - 1 + n) % n]);
+ if(FT_CURVE_TAG(tags[(i - 1 + n) % n]) == FT_Curve_Tag_Conic)
{
- next = (cur + next) * 0.5f;
-
- evaluateQuadraticCurve(prev, cur, next);
- ++i;
+ prev = (cur + prev) * 0.5;
+ AddPoint(prev);
+ }
- prev = next;
- cur = FTPoint(contour[i]);
- next = (i == n - 1)
- ? pointList[0]
- : FTPoint(contour[i + 1]);
+ // Next point is either the real next point or the midpoint.
+ FTPoint next(contour[(i + 1) % n]);
+ if(FT_CURVE_TAG(tags[(i + 1) % n]) == FT_Curve_Tag_Conic)
+ {
+ next = (cur + next) * 0.5;
}
evaluateQuadraticCurve(prev, cur, next);
- continue;
}
-
- if(tags[i] == FT_Curve_Tag_Cubic)
+ else if(FT_CURVE_TAG(tags[i]) == FT_Curve_Tag_Cubic
+ && FT_CURVE_TAG(tags[(i + 1) % n]) == FT_Curve_Tag_Cubic)
{
- FTPoint next2 = (i == n - 2)
- ? pointList[0]
- : FTPoint(contour[i + 2]);
- evaluateCubicCurve(prev, cur, next, next2);
- ++i;
- continue;
+ evaluateCubicCurve(FTPoint(contour[(i - 1 + n) % n]),
+ cur,
+ FTPoint(contour[(i + 1) % n]),
+ FTPoint(contour[(i + 2) % n]));
}
}
@@ -211,6 +206,7 @@ FTContour::FTContour(FT_Vector* contour, char* tags, unsigned int n)
outsetContour();
}
+
void FTContour::buildFrontOutset(float outset)
{
for(size_t i = 0; i < PointCount(); ++i)