ws and comment for recommended aa method

diff --git a/ext/gd/libgd/gd_interpolation.c b/ext/gd/libgd/gd_interpolation.c
index a1916a13d431f426cb20149f960a7052670bc69b..ccdefb9b46746318f3843e353888b29d9155d9d3 100644 (file)
--- a/ext/gd/libgd/gd_interpolation.c
+++ b/ext/gd/libgd/gd_interpolation.c
@@ -34,6 +34,17 @@
 
 */
 
+/*
+       Additional functions are available for simple rotation or up/downscaling.
+       downscaling using the fixed point implementations are usually much faster
+       than the existing gdImageCopyResampled while having a similar or better
+       quality.
+       
+       For image rotations, the optimized versions have a lazy antialiasing for 
+       the edges of the images. For a much better antialiased result, the affine
+       function is recommended.
+*/
+
 /*
 TODO:
  - Optimize pixel accesses and loops once we have continuous buffer
@@ -1004,24 +1015,24 @@ static inline void _gdScaleHoriz(gdImagePtr pSrc, unsigned int src_width, unsign
 static inline void _gdScaleCol (gdImagePtr pSrc,  unsigned int src_width, gdImagePtr pRes, unsigned int dst_width, unsigned int dst_height, unsigned int uCol, LineContribType *contrib)
 {
        unsigned int y;
-    for (y = 0; y < dst_height - 1; y++) {
-        register unsigned char r = 0, g = 0, b = 0, a = 0;
-        const int iLeft = contrib->ContribRow[y].Left;
-        const int iRight = contrib->ContribRow[y].Right;
+       for (y = 0; y < dst_height - 1; y++) {
+               register unsigned char r = 0, g = 0, b = 0, a = 0;
+               const int iLeft = contrib->ContribRow[y].Left;
+               const int iRight = contrib->ContribRow[y].Right;
                int i;
                int *row = pRes->tpixels[y];
 
                /* Accumulate each channel */
-        for (i = iLeft; i <= iRight; i++) {
-            const int pCurSrc = pSrc->tpixels[i][uCol];
+               for (i = iLeft; i <= iRight; i++) {
+                       const int pCurSrc = pSrc->tpixels[i][uCol];
                        const int i_iLeft = i - iLeft;
-            r += (unsigned char)(contrib->ContribRow[y].Weights[i_iLeft] * (double)(gdTrueColorGetRed(pCurSrc)));
-            g += (unsigned char)(contrib->ContribRow[y].Weights[i_iLeft] * (double)(gdTrueColorGetGreen(pCurSrc)));
-            b += (unsigned char)(contrib->ContribRow[y].Weights[i_iLeft] * (double)(gdTrueColorGetBlue(pCurSrc)));
+                       r += (unsigned char)(contrib->ContribRow[y].Weights[i_iLeft] * (double)(gdTrueColorGetRed(pCurSrc)));
+                       g += (unsigned char)(contrib->ContribRow[y].Weights[i_iLeft] * (double)(gdTrueColorGetGreen(pCurSrc)));
+                       b += (unsigned char)(contrib->ContribRow[y].Weights[i_iLeft] * (double)(gdTrueColorGetBlue(pCurSrc)));
                        a += (unsigned char)(contrib->ContribRow[y].Weights[i_iLeft] * (double)(gdTrueColorGetAlpha(pCurSrc)));
-        }
+               }
                pRes->tpixels[y][uCol] = gdTrueColorAlpha(r, g, b, a);
-    }
+       }
 }
 
 static inline void _gdScaleVert (const gdImagePtr pSrc, const unsigned int src_width, const unsigned int src_height, const gdImagePtr pDst, const unsigned int dst_width, const unsigned int dst_height)
@@ -1030,12 +1041,12 @@ static inline void _gdScaleVert (const gdImagePtr pSrc, const unsigned int src_w
        LineContribType * contrib;
 
        /* same height, copy it */
-    if (src_height == dst_height) {
+       if (src_height == dst_height) {
                unsigned int y;
                for (y = 0; y < src_height - 1; ++y) {
                        memcpy(pDst->tpixels[y], pSrc->tpixels[y], src_width);
                }
-    }
+       }
 
        contrib = _gdContributionsCalc(dst_height, src_height, (double)(dst_height) / (double)(src_height), pSrc->interpolation);
        /* scale each column */
@@ -1047,14 +1058,14 @@ static inline void _gdScaleVert (const gdImagePtr pSrc, const unsigned int src_w
 
 gdImagePtr gdImageScaleTwoPass(const gdImagePtr src, const unsigned int src_width, const unsigned int src_height, const unsigned int new_width, const unsigned int new_height)
 {
-    gdImagePtr tmp_im;
+       gdImagePtr tmp_im;
        gdImagePtr dst;
 
        tmp_im = gdImageCreateTrueColor(new_width, src_height);
        if (tmp_im == NULL) {
                return NULL;
        }
-       _gdScaleHoriz (src,  src_width, src_height, tmp_im, new_width, src_height);
+       _gdScaleHoriz(src, src_width, src_height, tmp_im, new_width, src_height);
 
        dst = gdImageCreateTrueColor(new_width, new_height);
        if (dst == NULL) {
@@ -1064,24 +1075,23 @@ gdImagePtr gdImageScaleTwoPass(const gdImagePtr src, const unsigned int src_widt
        _gdScaleVert(tmp_im, new_width, src_height, dst, new_width, new_height);
        gdFree(tmp_im);
 
-
-    return dst;
+       return dst;
 }
 
 gdImagePtr Scale(const gdImagePtr src, const unsigned int src_width, const unsigned int src_height, const gdImagePtr dst, const unsigned int new_width, const unsigned int new_height)
 {
-    gdImagePtr tmp_im;
+       gdImagePtr tmp_im;
 
        tmp_im = gdImageCreateTrueColor(new_width, src_height);
        if (tmp_im == NULL) {
                return NULL;
        }
-    _gdScaleHoriz(src, src_width, src_height, tmp_im, new_width, src_height);
+       _gdScaleHoriz(src, src_width, src_height, tmp_im, new_width, src_height);
 
-    _gdScaleVert(tmp_im, new_width, src_height, dst, new_width, new_height);
+       _gdScaleVert(tmp_im, new_width, src_height, dst, new_width, new_height);
 
        gdFree(tmp_im);
-    return dst;
+       return dst;
 }
 
 /*