Grid fitting tweaks.

Extract the grid fitting code from the scaling code and the affine image
drawing code into it's own separate function. This reduces code
duplication. It also allows us to make better allowance for rounding
errors.

Add a voodoo offset in the draw_affine.c code for painting interpolated
images. This gives us the best possible match between all the different
combinations of scaled/unscaled and interpolated/uninterpolated images.

1 files changed, 0 insertions, 59 deletions

diff --git a/draw/draw_simple_scale.c b/draw/draw_simple_scale.c
index fc706597..c2d429b1 100644
--- a/draw/draw_simple_scale.c
+++ b/draw/draw_simple_scale.c
@@ -1167,65 +1167,6 @@ scale_single_col(unsigned char *dst, unsigned char *src, fz_weights *weights, in
 #endif /* SINGLE_PIXEL_SPECIALS */
 
 fz_pixmap *
-fz_scale_pixmap_gridfit(fz_pixmap *src, float x, float y, float w, float h, int gridfit)
-{
-	if (gridfit) {
-		float n;
-		if (w > 0) {
-			/* Adjust the left hand edge, leftwards to a pixel boundary */
-			n = (float)(int)x;   /* n is now on a pixel boundary */
-			if (n > x)           /* Ensure it's the pixel boundary BELOW x */
-				n -= 1.0f;
-			w += x-n;            /* width gets wider as x >= n */
-			x = n;
-			/* Adjust the right hand edge rightwards to a pixel boundary */
-			n = (float)(int)w;   /* n is now the integer width <= w */
-			if (n != w)          /* If w isn't an integer already, bump it */
-				w = 1.0f + n;/* up to the next integer. */
-		} else {
-			/* Adjust the right hand edge, rightwards to a pixel boundary */
-			n = (float)(int)x;   /* n is now on a pixel boundary */
-			if (n > x)           /* Ensure it's the pixel boundary <= x */
-				n -= 1.0f;
-			if (n != x)          /* If x isn't on a pixel boundary already, */
-				n += 1.0f;   /* make n be the pixel boundary above x. */
-			w -= n-x;            /* Expand width (more negative!) as n >= x */
-			x = n;
-			/* Adjust the left hand edge leftwards to a pixel boundary */
-			n = (float)(int)w;
-			if (n != w)
-				w = n - 1.0f;
-		}
-		if (h > 0) {
-			/* Adjust the bottom edge, downwards to a pixel boundary */
-			n = (float)(int)y;   /* n is now on a pixel boundary */
-			if (n > y)           /* Ensure it's the pixel boundary BELOW y */
-				n -= 1.0f;
-			h += y-n;            /* height gets larger as y >= n */
-			y = n;
-			/* Adjust the top edge upwards to a pixel boundary */
-			n = (float)(int)h;   /* n is now the integer height <= h */
-			if (n != h)          /* If h isn't an integer already, bump it */
-				h = 1.0f + n;/* up to the next integer. */
-		} else {
-			/* Adjust the top edge, upwards to a pixel boundary */
-			n = (float)(int)y;   /* n is now on a pixel boundary */
-			if (n > y)           /* Ensure it's the pixel boundary <= y */
-			n -= 1.0f;
-			if (n != y)          /* If y isn't on a pixel boundary already, */
-				n += 1.0f;   /* make n be the pixel boundary above y. */
-			h -= n-y;            /* Expand height (more negative!) as n >= y */
-			y = n;
-			/* Adjust the bottom edge downwards to a pixel boundary */
-			n = (float)(int)h;
-			if (n != h)
-				h = n - 1.0f;
-		}
-	}
-	return fz_scale_pixmap(src, x, y, w, h);
-}
-
-fz_pixmap *
 fz_scale_pixmap(fz_pixmap *src, float x, float y, float w, float h)
 {
 	fz_scale_filter *filter = &fz_scale_filter_simple;