size_t
DecomposeIntoNoRepeatRects(const gfx::Rect& aRect,
const gfx::Rect& aTexCoordRect,
decomposedRectArrayT* aLayerRects,
decomposedRectArrayT* aTextureRects)
{
gfx::Rect texCoordRect = aTexCoordRect;
// If the texture should be flipped, it will have negative height. Detect that
// here and compensate for it. We will flip each rect as we emit it.
bool flipped = false;
if (texCoordRect.height < 0) {
flipped = true;
texCoordRect.y += texCoordRect.height;
texCoordRect.height = -texCoordRect.height;
}
// Wrap the texture coordinates so they are within [0,1] and cap width/height
// at 1. We rely on this below.
texCoordRect = gfx::Rect(gfx::Point(WrapTexCoord(texCoordRect.x),
WrapTexCoord(texCoordRect.y)),
gfx::Size(std::min(texCoordRect.width, 1.0f),
std::min(texCoordRect.height, 1.0f)));
NS_ASSERTION(texCoordRect.x >= 0.0f && texCoordRect.x <= 1.0f &&
texCoordRect.y >= 0.0f && texCoordRect.y <= 1.0f &&
texCoordRect.width >= 0.0f && texCoordRect.width <= 1.0f &&
texCoordRect.height >= 0.0f && texCoordRect.height <= 1.0f &&
texCoordRect.XMost() >= 0.0f && texCoordRect.XMost() <= 2.0f &&
texCoordRect.YMost() >= 0.0f && texCoordRect.YMost() <= 2.0f,
"We just wrapped the texture coordinates, didn't we?");
// Get the top left and bottom right points of the rectangle. Note that
// tl.x/tl.y are within [0,1] but br.x/br.y are within [0,2].
gfx::Point tl = texCoordRect.TopLeft();
gfx::Point br = texCoordRect.BottomRight();
NS_ASSERTION(tl.x >= 0.0f && tl.x <= 1.0f &&
tl.y >= 0.0f && tl.y <= 1.0f &&
br.x >= tl.x && br.x <= 2.0f &&
br.y >= tl.y && br.y <= 2.0f &&
FuzzyLTE(br.x - tl.x, 1.0f) &&
FuzzyLTE(br.y - tl.y, 1.0f),
"Somehow generated invalid texture coordinates");
// Then check if we wrap in either the x or y axis.
bool xwrap = br.x > 1.0f;
bool ywrap = br.y > 1.0f;
// If xwrap is false, the texture will be sampled from tl.x .. br.x.
// If xwrap is true, then it will be split into tl.x .. 1.0, and
// 0.0 .. WrapTexCoord(br.x). Same for the Y axis. The destination
// rectangle is also split appropriately, according to the calculated
// xmid/ymid values.
if (!xwrap && !ywrap) {
SetRects(0, aLayerRects, aTextureRects,
aRect.x, aRect.y, aRect.XMost(), aRect.YMost(),
tl.x, tl.y, br.x, br.y,
flipped);
return 1;
}
// If we are dealing with wrapping br.x and br.y are greater than 1.0 so
// wrap them here as well.
br = gfx::Point(xwrap ? WrapTexCoord(br.x) : br.x,
ywrap ? WrapTexCoord(br.y) : br.y);
// If we wrap around along the x axis, we will draw first from
// tl.x .. 1.0 and then from 0.0 .. br.x (which we just wrapped above).
// The same applies for the Y axis. The midpoints we calculate here are
// only valid if we actually wrap around.
GLfloat xmid = aRect.x + (1.0f - tl.x) / texCoordRect.width * aRect.width;
GLfloat ymid = aRect.y + (1.0f - tl.y) / texCoordRect.height * aRect.height;
NS_ASSERTION(!xwrap ||
(xmid > aRect.x &&
xmid < aRect.XMost() &&
FuzzyEqual((xmid - aRect.x) + (aRect.XMost() - xmid), aRect.width)),
"xmid should be within [x,XMost()] and the wrapped rect should have the same width");
NS_ASSERTION(!ywrap ||
(ymid > aRect.y &&
ymid < aRect.YMost() &&
FuzzyEqual((ymid - aRect.y) + (aRect.YMost() - ymid), aRect.height)),
"ymid should be within [y,YMost()] and the wrapped rect should have the same height");
if (!xwrap && ywrap) {
SetRects(0, aLayerRects, aTextureRects,
aRect.x, aRect.y, aRect.XMost(), ymid,
tl.x, tl.y, br.x, 1.0f,
flipped);
SetRects(1, aLayerRects, aTextureRects,
aRect.x, ymid, aRect.XMost(), aRect.YMost(),
tl.x, 0.0f, br.x, br.y,
flipped);
return 2;
}
if (xwrap && !ywrap) {
SetRects(0, aLayerRects, aTextureRects,
aRect.x, aRect.y, xmid, aRect.YMost(),
tl.x, tl.y, 1.0f, br.y,
flipped);
SetRects(1, aLayerRects, aTextureRects,
xmid, aRect.y, aRect.XMost(), aRect.YMost(),
0.0f, tl.y, br.x, br.y,
flipped);
return 2;
}
SetRects(0, aLayerRects, aTextureRects,
aRect.x, aRect.y, xmid, ymid,
tl.x, tl.y, 1.0f, 1.0f,
flipped);
SetRects(1, aLayerRects, aTextureRects,
xmid, aRect.y, aRect.XMost(), ymid,
0.0f, tl.y, br.x, 1.0f,
flipped);
SetRects(2, aLayerRects, aTextureRects,
aRect.x, ymid, xmid, aRect.YMost(),
tl.x, 0.0f, 1.0f, br.y,
flipped);
SetRects(3, aLayerRects, aTextureRects,
xmid, ymid, aRect.XMost(), aRect.YMost(),
0.0f, 0.0f, br.x, br.y,
flipped);
return 4;
}
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);
}
}
