CF2_Fixed stemWidth,
CF2_Fixed* darkenAmount,
CF2_Fixed boldenAmount,
- FT_Bool stemDarkened )
+ FT_Bool stemDarkened,
+ FT_Int* darkenParams )
{
+ /*
+ * Total darkening amount is computed in 1000 unit character space
+ * using the modified 5 part curve as Adobe's Avalon rasterizer.
+ * The darkening amount is smaller for thicker stems.
+ * It becomes zero when the stem is thicker than 2.333 pixels.
+ *
+ * By default, we use
+ *
+ * darkenAmount = 0.4 pixels if scaledStem <= 0.5 pixels,
+ * darkenAmount = 0.275 pixels if 1 <= scaledStem <= 1.667 pixels,
+ * darkenAmount = 0 pixel if scaledStem >= 2.333 pixels,
+ *
+ * and piecewise linear in-between:
+ *
+ *
+ * darkening
+ * ^
+ * |
+ * | (x1,y1)
+ * |--------+
+ * | \
+ * | \
+ * | \ (x3,y3)
+ * | +----------+
+ * | (x2,y2) \
+ * | \
+ * | \
+ * | +-----------------
+ * | (x4,y4)
+ * +---------------------------------------------> stem
+ * thickness
+ *
+ *
+ * This corresponds to the following values for the
+ * `darkening-parameters' property:
+ *
+ * (x1, y1) = (500, 400)
+ * (x2, y2) = (1000, 275)
+ * (x3, y3) = (1667, 275)
+ * (x4, y4) = (2333, 0)
+ *
+ */
+
/* Internal calculations are done in units per thousand for */
- /* convenience. */
+ /* convenience. The x axis is scaled stem width in */
+ /* thousandths of a pixel. That is, 1000 is 1 pixel. */
+ /* The y axis is darkening amount in thousandths of a pixel.*/
+ /* In the code, below, dividing by ppem and */
+ /* adjusting for emRatio converts darkenAmount to character */
+ /* space (font units). */
CF2_Fixed stemWidthPer1000, scaledStem;
if ( stemDarkened )
{
+ FT_Int x1 = darkenParams[0];
+ FT_Int y1 = darkenParams[1];
+ FT_Int x2 = darkenParams[2];
+ FT_Int y2 = darkenParams[3];
+ FT_Int x3 = darkenParams[4];
+ FT_Int y3 = darkenParams[5];
+ FT_Int x4 = darkenParams[6];
+ FT_Int y4 = darkenParams[7];
+
+
/* convert from true character space to 1000 unit character space; */
/* add synthetic emboldening effect */
stemWidthPer1000 <= ( stemWidth + boldenAmount ) )
{
stemWidthPer1000 = 0; /* to pacify compiler */
- scaledStem = cf2_intToFixed( 2333 );
+ scaledStem = cf2_intToFixed( x4 );
}
else
{
if ( ppem > CF2_FIXED_ONE &&
scaledStem <= stemWidthPer1000 )
- scaledStem = cf2_intToFixed( 2333 );
+ scaledStem = cf2_intToFixed( x4 );
+ }
+
+ /* now apply the darkening parameters */
+
+ if ( scaledStem < cf2_intToFixed( x1 ) )
+ *darkenAmount = FT_DivFix( cf2_intToFixed( y1 ), ppem );
+
+ else if ( scaledStem < cf2_intToFixed( x2 ) )
+ {
+ FT_Int xdelta = x2 - x1;
+ FT_Int ydelta = y2 - y1;
+ FT_Int x = stemWidthPer1000 -
+ FT_DivFix( cf2_intToFixed( x1 ), ppem );
+
+
+ if ( !xdelta )
+ goto Try_x3;
+
+ *darkenAmount = FT_MulFix( x, FT_DivFix( ydelta, xdelta ) ) +
+ FT_DivFix( cf2_intToFixed( y1 ), ppem );
+ }
+
+ else if ( scaledStem < cf2_intToFixed( x3 ) )
+ {
+ Try_x3:
+ {
+ FT_Int xdelta = x3 - x2;
+ FT_Int ydelta = y3 - y2;
+ FT_Int x = stemWidthPer1000 -
+ FT_DivFix( cf2_intToFixed( x2 ), ppem );
+
+
+ if ( !xdelta )
+ goto Try_x4;
+
+ *darkenAmount = FT_MulFix( x, FT_DivFix( ydelta, xdelta ) ) +
+ FT_DivFix( cf2_intToFixed( y2 ), ppem );
+ }
}
- /*
- * Total darkening amount is computed in 1000 unit character space
- * using the modified 5 part curve as Avalon rasterizer.
- * The darkening amount is smaller for thicker stems.
- * It becomes zero when the stem is thicker than 2.333 pixels.
- *
- * In Avalon rasterizer,
- *
- * darkenAmount = 0.5 pixels if scaledStem <= 0.5 pixels,
- * darkenAmount = 0.333 pixels if 1 <= scaledStem <= 1.667 pixels,
- * darkenAmount = 0 pixel if scaledStem >= 2.333 pixels,
- *
- * and piecewise linear in-between.
- *
- */
- if ( scaledStem < cf2_intToFixed( 500 ) )
- *darkenAmount = FT_DivFix( cf2_intToFixed( 400 ), ppem );
-
- else if ( scaledStem < cf2_intToFixed( 1000 ) )
- *darkenAmount = FT_DivFix( cf2_intToFixed( 525 ), ppem ) -
- FT_MulFix( stemWidthPer1000,
- cf2_floatToFixed( .25 ) );
-
- else if ( scaledStem < cf2_intToFixed( 1667 ) )
- *darkenAmount = FT_DivFix( cf2_intToFixed( 275 ), ppem );
-
- else if ( scaledStem < cf2_intToFixed( 2333 ) )
- *darkenAmount = FT_DivFix( cf2_intToFixed( 963 ), ppem ) -
- FT_MulFix( stemWidthPer1000,
- cf2_floatToFixed( .413 ) );
+ else if ( scaledStem < cf2_intToFixed( x4 ) )
+ {
+ Try_x4:
+ {
+ FT_Int xdelta = x4 - x3;
+ FT_Int ydelta = y4 - y3;
+ FT_Int x = stemWidthPer1000 -
+ FT_DivFix( cf2_intToFixed( x3 ), ppem );
+
+
+ if ( !xdelta )
+ goto Use_y4;
+
+ *darkenAmount = FT_MulFix( x, FT_DivFix( ydelta, xdelta ) ) +
+ FT_DivFix( cf2_intToFixed( y3 ), ppem );
+ }
+ }
+
+ else
+ {
+ Use_y4:
+ *darkenAmount = FT_DivFix( cf2_intToFixed( y4 ), ppem );
+ }
/* use half the amount on each side and convert back to true */
/* character space */
font->stdVW,
&font->darkenX,
boldenX,
- FALSE );
+ FALSE,
+ font->darkenParams );
}
else
cf2_computeDarkening( emRatio,
font->stdVW,
&font->darkenX,
0,
- font->stemDarkened );
+ font->stemDarkened,
+ font->darkenParams );
#if 0
/* since hstem is measured in the y-direction, we use the `d' member */
font->stdHW,
&font->darkenY,
boldenY,
- font->stemDarkened );
+ font->stemDarkened,
+ font->darkenParams );
if ( font->darkenX != 0 || font->darkenY != 0 )
font->darkened = TRUE;
projects / reactos.git / blobdiff