diff --git a/spine-cpp/spine-cpp/src/spine/SkeletonClipping.cpp b/spine-cpp/spine-cpp/src/spine/SkeletonClipping.cpp index 30be38675..f0ad30b84 100644 --- a/spine-cpp/spine-cpp/src/spine/SkeletonClipping.cpp +++ b/spine-cpp/spine-cpp/src/spine/SkeletonClipping.cpp @@ -292,56 +292,53 @@ bool SkeletonClipping::clip(float x1, float y1, float x2, float y2, float x3, fl input->add(y1); output->clear(); - Vector &clippingVertices = *clippingArea; size_t clippingVerticesLast = clippingArea->size() - 4; + Vector &clippingVertices = *clippingArea; for (size_t i = 0;; i += 2) { float edgeX = clippingVertices[i], edgeY = clippingVertices[i + 1]; - float edgeX2 = clippingVertices[i + 2], edgeY2 = clippingVertices[i + 3]; - float deltaX = edgeX - edgeX2, deltaY = edgeY - edgeY2; + float ex = edgeX - clippingVertices[i + 2], ey = edgeY - clippingVertices[i + 3]; + size_t outputStart = output->size(); Vector &inputVertices = *input; - size_t inputVerticesLength = input->size() - 2, outputStart = output->size(); - for (size_t ii = 0; ii < inputVerticesLength; ii += 2) { - float inputX = inputVertices[ii], inputY = inputVertices[ii + 1]; - float inputX2 = inputVertices[ii + 2], inputY2 = inputVertices[ii + 3]; - bool side2 = deltaX * (inputY2 - edgeY2) - deltaY * (inputX2 - edgeX2) > 0; - if (deltaX * (inputY - edgeY2) - deltaY * (inputX - edgeX2) > 0) { - if (side2) { - // v1 inside, v2 inside - output->add(inputX2); - output->add(inputY2); - continue; - } - // v1 inside, v2 outside - float c0 = inputY2 - inputY, c2 = inputX2 - inputX; - float s = c0 * (edgeX2 - edgeX) - c2 * (edgeY2 - edgeY); - if (MathUtil::abs(s) > 0.000001f) { - float ua = (c2 * (edgeY - inputY) - c0 * (edgeX - inputX)) / s; - output->add(edgeX + (edgeX2 - edgeX) * ua); - output->add(edgeY + (edgeY2 - edgeY) * ua); - } else { - output->add(edgeX); - output->add(edgeY); - } - } else if (side2) { - // v1 outside, v2 inside - float c0 = inputY2 - inputY, c2 = inputX2 - inputX; - float s = c0 * (edgeX2 - edgeX) - c2 * (edgeY2 - edgeY); - if (MathUtil::abs(s) > 0.000001f) { - float ua = (c2 * (edgeY - inputY) - c0 * (edgeX - inputX)) / s; - output->add(edgeX + (edgeX2 - edgeX) * ua); - output->add(edgeY + (edgeY2 - edgeY) * ua); - } else { - output->add(edgeX); - output->add(edgeY); - } - output->add(inputX2); - output->add(inputY2); - } - clipped = true; - } + for (size_t ii = 0, nn = input->size() - 2; ii < nn;) { + float inputX = inputVertices[ii], inputY = inputVertices[ii + 1]; + ii += 2; + float inputX2 = inputVertices[ii], inputY2 = inputVertices[ii + 1]; + float s2 = ey * (edgeX - inputX2) > ex * (edgeY - inputY2); + float s1 = ey * (edgeX - inputX) - ex * (edgeY - inputY); + if (s1 > 0) { + if (s2) { // v1 inside, v2 inside + output->add(inputX2); + output->add(inputY2); + continue; + } + // v1 inside, v2 outside + float ix = inputX2 - inputX, iy = inputY2 - inputY, t = s1 / (ix * ey - iy * ex); + if (t >= 0 && t <= 1) { + output->add(inputX + ix * t); + output->add(inputY + iy * t); + } else { + output->add(inputX2); + output->add(inputY2); + } + } else if (s2) { // v1 outside, v2 inside + float ix = inputX2 - inputX, iy = inputY2 - inputY, t = s1 / (ix * ey - iy * ex); + if (t >= 0 && t <= 1) { + output->add(inputX + ix * t); + output->add(inputY + iy * t); + output->add(inputX2); + output->add(inputY2); + } else { + output->add(inputX2); + output->add(inputY2); + continue; + } + } + clipped = true; + } - if (outputStart == output->size()) { + + if (outputStart == output->size()) { // All edges outside. originalOutput->clear(); return true;