Example #1
0
Mat3
SubRectMat3(const gfx::IntRect& subrect, const gfx::IntSize& size)
{
    return SubRectMat3(float(subrect.X()) / size.width,
                       float(subrect.Y()) / size.height,
                       float(subrect.Width()) / size.width,
                       float(subrect.Height()) / size.height);
}
Example #2
0
Mat3
SubRectMat3(const gfx::IntRect& bigSubrect, const gfx::IntSize& smallSize,
            const gfx::IntSize& divisors)
{
    const float x = float(bigSubrect.X()) / divisors.width;
    const float y = float(bigSubrect.Y()) / divisors.height;
    const float w = float(bigSubrect.Width()) / divisors.width;
    const float h = float(bigSubrect.Height()) / divisors.height;
    return SubRectMat3(x / smallSize.width,
                       y / smallSize.height,
                       w / smallSize.width,
                       h / smallSize.height);
}
void
DecomposeIntoNoRepeatTriangles(const gfx::IntRect& aTexCoordRect,
                               const gfx::IntSize& aTexSize,
                               RectTriangles& aRects,
                               bool aFlipY /* = false */)
{
    // normalize this
    gfx::IntRect tcr(aTexCoordRect);
    while (tcr.x >= aTexSize.width)
        tcr.x -= aTexSize.width;
    while (tcr.y >= aTexSize.height)
        tcr.y -= aTexSize.height;

    // Compute top left and bottom right tex coordinates
    GLfloat tl[2] =
        { GLfloat(tcr.x) / GLfloat(aTexSize.width),
          GLfloat(tcr.y) / GLfloat(aTexSize.height) };
    GLfloat br[2] =
        { GLfloat(tcr.XMost()) / GLfloat(aTexSize.width),
          GLfloat(tcr.YMost()) / GLfloat(aTexSize.height) };

    // then check if we wrap in either the x or y axis; if we do,
    // then also use fmod to figure out the "true" non-wrapping
    // texture coordinates.

    bool xwrap = false, ywrap = false;
    if (tcr.x < 0 || tcr.x > aTexSize.width ||
        tcr.XMost() < 0 || tcr.XMost() > aTexSize.width)
    {
        xwrap = true;
        tl[0] = WrapTexCoord(tl[0]);
        br[0] = WrapTexCoord(br[0]);
    }

    if (tcr.y < 0 || tcr.y > aTexSize.height ||
        tcr.YMost() < 0 || tcr.YMost() > aTexSize.height)
    {
        ywrap = true;
        tl[1] = WrapTexCoord(tl[1]);
        br[1] = WrapTexCoord(br[1]);
    }

    NS_ASSERTION(tl[0] >= 0.0f && tl[0] <= 1.0f &&
                 tl[1] >= 0.0f && tl[1] <= 1.0f &&
                 br[0] >= 0.0f && br[0] <= 1.0f &&
                 br[1] >= 0.0f && br[1] <= 1.0f,
                 "Somehow generated invalid texture coordinates");

    // If xwrap is false, the texture will be sampled from tl[0]
    // .. br[0].  If xwrap is true, then it will be split into tl[0]
    // .. 1.0, and 0.0 .. br[0].  Same for the Y axis.  The
    // destination rectangle is also split appropriately, according
    // to the calculated xmid/ymid values.

    // There isn't a 1:1 mapping between tex coords and destination coords;
    // when computing midpoints, we have to take that into account.  We
    // need to map the texture coords, which are (in the wrap case):
    // |tl->1| and |0->br| to the |0->1| range of the vertex coords.  So
    // we have the length (1-tl)+(br) that needs to map into 0->1.
    // These are only valid if there is wrap involved, they won't be used
    // otherwise.
    GLfloat xlen = (1.0f - tl[0]) + br[0];
    GLfloat ylen = (1.0f - tl[1]) + br[1];

    NS_ASSERTION(!xwrap || xlen > 0.0f, "xlen isn't > 0, what's going on?");
    NS_ASSERTION(!ywrap || ylen > 0.0f, "ylen isn't > 0, what's going on?");
    NS_ASSERTION(aTexCoordRect.Width() <= aTexSize.width &&
                 aTexCoordRect.Height() <= aTexSize.height, "tex coord rect would cause tiling!");

    if (!xwrap && !ywrap) {
        aRects.addRect(0.0f, 0.0f,
                       1.0f, 1.0f,
                       tl[0], tl[1],
                       br[0], br[1],
                       aFlipY);
    } else if (!xwrap && ywrap) {
        GLfloat ymid = (1.0f - tl[1]) / ylen;
        aRects.addRect(0.0f, 0.0f,
                       1.0f, ymid,
                       tl[0], tl[1],
                       br[0], 1.0f,
                       aFlipY);
        aRects.addRect(0.0f, ymid,
                       1.0f, 1.0f,
                       tl[0], 0.0f,
                       br[0], br[1],
                       aFlipY);
    } else if (xwrap && !ywrap) {
        GLfloat xmid = (1.0f - tl[0]) / xlen;
        aRects.addRect(0.0f, 0.0f,
                       xmid, 1.0f,
                       tl[0], tl[1],
                       1.0f, br[1],
                       aFlipY);
        aRects.addRect(xmid, 0.0f,
                       1.0f, 1.0f,
                       0.0f, tl[1],
                       br[0], br[1],
                       aFlipY);
    } else {
        GLfloat xmid = (1.0f - tl[0]) / xlen;
        GLfloat ymid = (1.0f - tl[1]) / ylen;
        aRects.addRect(0.0f, 0.0f,
                       xmid, ymid,
                       tl[0], tl[1],
                       1.0f, 1.0f,
                       aFlipY);
        aRects.addRect(xmid, 0.0f,
                       1.0f, ymid,
                       0.0f, tl[1],
                       br[0], 1.0f,
                       aFlipY);
        aRects.addRect(0.0f, ymid,
                       xmid, 1.0f,
                       tl[0], 0.0f,
                       1.0f, br[1],
                       aFlipY);
        aRects.addRect(xmid, ymid,
                       1.0f, 1.0f,
                       0.0f, 0.0f,
                       br[0], br[1],
                       aFlipY);
    }
}