tree bcfd9601f36a77cfede262b950b75ce750d0b34c
parent a8110001165ca60597deb24ef6ef61458a2a0bf7
author Sam Lantinga <slouken@libsdl.org> 1475888430 -0700
committer Sam Lantinga <slouken@libsdl.org> 1475888430 -0700

Fixed bug 3029 - software renderer cuts off edges when rotate-blitting with a multiple of 90 degrees

Adam M.

When doing a rotated texture copy with the software renderer, where the angle is a multiple of 90 degrees, one or two edges of the image get cut off. This is because of the following line in sw_rotate.c:
    if ((unsigned)dx < (unsigned)sw && (unsigned)dy < (unsigned)sh) {
which is effectively saying:
    if (dx >= 0 && dx < src->w-1 && dy >= 0 && dy < src->h-1) {

As a result, it doesn't process pixels in the right column or bottom row of the source image (except when they're accessed as part of the bilinear filtering for nearby pixels). This causes it to look like the edges are cut off, and it's especially obvious with an exact multiple of 90 degrees.