Fix a couple of bugs in the bilinear fetcher

- The x and y distances are the most significant fractional bits.

- We need to fetch four times the number pixels produced.

diff --git a/pixman/pixman-transformed.c b/pixman/pixman-transformed.c
index 4fcd4c0..308f4c4 100644 (file)
--- a/pixman/pixman-transformed.c
+++ b/pixman/pixman-transformed.c
@@ -295,8 +295,8 @@ fetch_bilinear_pixels (bits_image_t *image, uint32_t *buffer, int n_pixels)
            int32_t x1, y1, x2, y2;
            x1 = coords[0];
            y1 = coords[1];
-           distx = x1 & 0xff;
-           disty = y1 & 0xff;
+           distx = (x1 >> 8) & 0xff;
+           disty = (y1 >> 8) & 0xff;
            x1 >>= 16;
            y1 >>= 16;
            x2 = x1 + 1;
@@ -317,7 +317,7 @@ fetch_bilinear_pixels (bits_image_t *image, uint32_t *buffer, int n_pixels)
            coords += 2;
        }
 
-       fetch_extended (image, temps, tmp_n_pixels);
+       fetch_extended (image, temps, tmp_n_pixels * 4);
 
        u = (uint32_t *)temps;
        d = dists;
@@ -791,6 +791,8 @@ ACCESS(fbFetchTransformed)(bits_image_t * pict, int x, int y, int width,
                    coords[1] = div >> 16;
            }
 
+           coords += 2;
+
            v.vector[0] += unit.vector[0];
            v.vector[1] += unit.vector[1];
            v.vector[2] += unit.vector[2];
@@ -806,9 +808,34 @@ ACCESS(fbFetchTransformed)(bits_image_t * pict, int x, int y, int width,
        case PIXMAN_FILTER_BILINEAR:
        case PIXMAN_FILTER_GOOD:
        case PIXMAN_FILTER_BEST:
+       {
+#if 0
+           int k;
+           for (k = 0; k < n_pixels; ++k)
+           {
+               int32_t x, y;
+               uint32_t r1;
+               pixman_vector_t vv;
+
+               x = tmp_buffer[2 * k];
+               y = tmp_buffer[2 * k + 1];
+
+               vv.vector[0] = x;
+               vv.vector[1] = y;
+               vv.vector[2] = 1 << 16;
+               
+               r1 = fetch_bilinear (pict, affine, pict->common.repeat, FALSE, &vv);
+               
+               fetch_bilinear_pixels (pict, (uint32_t *)&(vv.vector), 1);
+
+               if (r1 != (uint32_t)vv.vector[0])
+                   assert (r1 == (uint32_t) (vv.vector[0]));
+           }
+#endif
+               
            fetch_bilinear_pixels (pict, tmp_buffer, n_pixels);
            break;
-
+       }
        case PIXMAN_FILTER_CONVOLUTION:
            fetch_convolution_pixels (pict, tmp_buffer, n_pixels);
            break;