diff options
| -rw-r--r-- | pixman/pixman.c | 94 |
1 files changed, 36 insertions, 58 deletions
diff --git a/pixman/pixman.c b/pixman/pixman.c index 264a56b2..3ecd3115 100644 --- a/pixman/pixman.c +++ b/pixman/pixman.c @@ -514,45 +514,9 @@ compute_transformed_extents (pixman_transform_t *transform, return TRUE; } -static pixman_bool_t -compute_sample_extents (pixman_transform_t *transform, - pixman_box32_t *extents, - pixman_fixed_t x_off, pixman_fixed_t y_off, - pixman_fixed_t width, pixman_fixed_t height) -{ - box_48_16_t transformed; - - if (!compute_transformed_extents (transform, extents, &transformed)) - return FALSE; - - /* Expand the source area by a tiny bit so account of different rounding that - * may happen during sampling. Note that (8 * pixman_fixed_e) is very far from - * 0.5 so this won't cause the area computed to be overly pessimistic. - */ - transformed.x1 += x_off - 8 * pixman_fixed_e; - transformed.y1 += y_off - 8 * pixman_fixed_e; - transformed.x2 += x_off + width + 8 * pixman_fixed_e; - transformed.y2 += y_off + height + 8 * pixman_fixed_e; - - if (transformed.x1 < pixman_min_fixed_48_16 || transformed.x1 > pixman_max_fixed_48_16 || - transformed.y1 < pixman_min_fixed_48_16 || transformed.y1 > pixman_max_fixed_48_16 || - transformed.x2 < pixman_min_fixed_48_16 || transformed.x2 > pixman_max_fixed_48_16 || - transformed.y2 < pixman_min_fixed_48_16 || transformed.y2 > pixman_max_fixed_48_16) - { - return FALSE; - } - else - { - extents->x1 = pixman_fixed_to_int (transformed.x1); - extents->y1 = pixman_fixed_to_int (transformed.y1); - extents->x2 = pixman_fixed_to_int (transformed.x2) + 1; - extents->y2 = pixman_fixed_to_int (transformed.y2) + 1; - - return TRUE; - } -} - #define IS_16BIT(x) (((x) >= INT16_MIN) && ((x) <= INT16_MAX)) +#define ABS(f) (((f) < 0)? (-(f)) : (f)) +#define IS_16_16(f) (((f) >= pixman_min_fixed_48_16 && ((f) <= pixman_max_fixed_48_16))) static pixman_bool_t analyze_extent (pixman_image_t *image, @@ -563,7 +527,8 @@ analyze_extent (pixman_image_t *image, pixman_fixed_t *params; pixman_fixed_t x_off, y_off; pixman_fixed_t width, height; - pixman_box32_t ex; + pixman_fixed_t m00, m10; + box_48_16_t transformed; if (!image) return TRUE; @@ -633,17 +598,6 @@ analyze_extent (pixman_image_t *image, default: return FALSE; } - - /* Check whether the non-expanded, transformed extent is entirely within - * the source image, and set the FAST_PATH_SAMPLES_COVER_CLIP if it is. - */ - ex = *extents; - if (compute_sample_extents (transform, &ex, x_off, y_off, width, height) && - ex.x1 >= 0 && ex.y1 >= 0 && - ex.x2 <= image->bits.width && ex.y2 <= image->bits.height) - { - *flags |= FAST_PATH_SAMPLES_COVER_CLIP; - } } else { @@ -653,17 +607,41 @@ analyze_extent (pixman_image_t *image, height = 0; } - /* Check that the extents expanded by one don't overflow. This ensures that - * compositing functions can simply walk the source space using 16.16 - * variables without worrying about overflow. + if (!compute_transformed_extents (transform, extents, &transformed)) + return FALSE; + + /* Expand the source area by a tiny bit so account of different rounding that + * may happen during sampling. Note that (8 * pixman_fixed_e) is very far from + * 0.5 so this won't cause the area computed to be overly pessimistic. + */ + transformed.x1 += x_off - 8 * pixman_fixed_e; + transformed.y1 += y_off - 8 * pixman_fixed_e; + transformed.x2 += x_off + width + 8 * pixman_fixed_e; + transformed.y2 += y_off + height + 8 * pixman_fixed_e; + + /* Check we don't overflow when the destination extents are expanded by one. + * This ensures that compositing functions can simply walk the source space + * using 16.16 variables without worrying about overflow. */ - ex.x1 = extents->x1 - 1; - ex.y1 = extents->y1 - 1; - ex.x2 = extents->x2 + 1; - ex.y2 = extents->y2 + 1; + m00 = transform? ABS (transform->matrix[0][0]) : pixman_fixed_1; + m10 = transform? ABS (transform->matrix[1][0]) : 0; - if (!compute_sample_extents (transform, &ex, x_off, y_off, width, height)) + if (!IS_16_16 (transformed.x1 - m00) || + !IS_16_16 (transformed.y1 - m10) || + !IS_16_16 (transformed.x2 + m00) || + !IS_16_16 (transformed.y2 + m10)) + { return FALSE; + } + + if (image->common.type == BITS && + pixman_fixed_to_int (transformed.x1) >= 0 && + pixman_fixed_to_int (transformed.y1) >= 0 && + pixman_fixed_to_int (transformed.x2) < image->bits.width && + pixman_fixed_to_int (transformed.y2) < image->bits.height) + { + *flags |= FAST_PATH_SAMPLES_COVER_CLIP; + } return TRUE; } |