ThorVG: update to v0.11.0 release.

See https://github.com/thorvg/thorvg/releases/tag/v0.11.0

+ Infrastructure
    Repository folder structure was make it more intuitive and coherent.
        "thorvg/src/lib" -> "thorvg/src/common"
            (providing essential common functionalities
                used internally among the renderer and sub-modules)
        "thorvg/src/lib" -> "thorvg/src/renderer"
            (for vector drawing features)

+ SVG related
    Fix stroke regression https://github.com/thorvg/thorvg/issues/1670
    Support stroke dash offset function https://github.com/thorvg/thorvg/issues/1591#issuecomment-1681319321
    Support Focal property in Radial Gradient https://github.com/thorvg/thorvg/issues/1558

1 files changed, 1207 insertions, 0 deletions

diff --git a/thirdparty/thorvg/src/renderer/sw_engine/tvgSwRasterTexmap.h b/thirdparty/thorvg/src/renderer/sw_engine/tvgSwRasterTexmap.h
new file mode 100644
index 0000000000..698ab37da2
--- /dev/null
+++ b/thirdparty/thorvg/src/renderer/sw_engine/tvgSwRasterTexmap.h
@@ -0,0 +1,1207 @@
+/*
+ * Copyright (c) 2021 - 2023 the ThorVG project. All rights reserved.
+
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+struct AALine
+{
+   int32_t x[2];
+   int32_t coverage[2];
+   int32_t length[2];
+};
+
+struct AASpans
+{
+   AALine *lines;
+   int32_t yStart;
+   int32_t yEnd;
+};
+
+static inline void _swap(float& a, float& b, float& tmp)
+{
+    tmp = a;
+    a = b;
+    b = tmp;
+}
+
+
+//Careful! Shared resource, No support threading
+static float dudx, dvdx;
+static float dxdya, dxdyb, dudya, dvdya;
+static float xa, xb, ua, va;
+
+
+//Y Range exception handling
+static bool _arrange(const SwImage* image, const SwBBox* region, int& yStart, int& yEnd)
+{
+    int32_t regionTop, regionBottom;
+
+    if (region) {
+        regionTop = region->min.y;
+        regionBottom = region->max.y;
+    } else {
+        regionTop = image->rle->spans->y;
+        regionBottom = image->rle->spans[image->rle->size - 1].y;
+    }
+
+    if (yStart >= regionBottom) return false;
+
+    if (yStart < regionTop) yStart = regionTop;
+    if (yEnd > regionBottom) yEnd = regionBottom;
+
+    return true;
+}
+
+
+static bool _rasterMaskedPolygonImageSegment(SwSurface* surface, const SwImage* image, const SwBBox* region, int yStart, int yEnd, AASpans* aaSpans, uint8_t opacity, uint8_t dirFlag = 0)
+{
+    return false;
+
+#if 0 //Enable it when GRAYSCALE image is supported
+    auto maskOp = _getMaskOp(surface->compositor->method);
+    auto direct = _direct(surface->compositor->method);
+    float _dudx = dudx, _dvdx = dvdx;
+    float _dxdya = dxdya, _dxdyb = dxdyb, _dudya = dudya, _dvdya = dvdya;
+    float _xa = xa, _xb = xb, _ua = ua, _va = va;
+    auto sbuf = image->buf8;
+    int32_t sw = static_cast<int32_t>(image->stride);
+    int32_t sh = image->h;
+    int32_t x1, x2, x, y, ar, ab, iru, irv, px, ay;
+    int32_t vv = 0, uu = 0;
+    int32_t minx = INT32_MAX, maxx = INT32_MIN;
+    float dx, u, v, iptr;
+    SwSpan* span = nullptr;         //used only when rle based.
+
+    if (!_arrange(image, region, yStart, yEnd)) return false;
+
+    //Loop through all lines in the segment
+    uint32_t spanIdx = 0;
+
+    if (region) {
+        minx = region->min.x;
+        maxx = region->max.x;
+    } else {
+        span = image->rle->spans;
+        while (span->y < yStart) {
+            ++span;
+            ++spanIdx;
+        }
+    }
+
+    y = yStart;
+
+    while (y < yEnd) {
+        x1 = (int32_t)_xa;
+        x2 = (int32_t)_xb;
+
+        if (!region) {
+            minx = INT32_MAX;
+            maxx = INT32_MIN;
+            //one single row, could be consisted of multiple spans.
+            while (span->y == y && spanIdx < image->rle->size) {
+                if (minx > span->x) minx = span->x;
+                if (maxx < span->x + span->len) maxx = span->x + span->len;
+                ++span;
+                ++spanIdx;
+            }
+        }
+        if (x1 < minx) x1 = minx;
+        if (x2 > maxx) x2 = maxx;
+
+        //Anti-Aliasing frames
+        ay = y - aaSpans->yStart;
+        if (aaSpans->lines[ay].x[0] > x1) aaSpans->lines[ay].x[0] = x1;
+        if (aaSpans->lines[ay].x[1] < x2) aaSpans->lines[ay].x[1] = x2;
+
+        //Range allowed
+        if ((x2 - x1) >= 1 && (x1 < maxx) && (x2 > minx)) {
+
+            //Perform subtexel pre-stepping on UV
+            dx = 1 - (_xa - x1);
+            u = _ua + dx * _dudx;
+            v = _va + dx * _dvdx;
+
+            x = x1;
+
+            auto cmp = &surface->compositor->image.buf8[y * surface->compositor->image.stride + x1];
+            auto dst = &surface->buf8[y * surface->stride + x1];
+
+            if (opacity == 255) {
+                //Draw horizontal line
+                while (x++ < x2) {
+                    uu = (int) u;
+                    if (uu >= sw) continue;
+                    vv = (int) v;
+                    if (vv >= sh) continue;
+
+                    ar = (int)(255 * (1 - modff(u, &iptr)));
+                    ab = (int)(255 * (1 - modff(v, &iptr)));
+                    iru = uu + 1;
+                    irv = vv + 1;
+
+                    px = *(sbuf + (vv * sw) + uu);
+
+                    /* horizontal interpolate */
+                    if (iru < sw) {
+                        /* right pixel */
+                        int px2 = *(sbuf + (vv * sw) + iru);
+                        px = INTERPOLATE(px, px2, ar);
+                    }
+                    /* vertical interpolate */
+                    if (irv < sh) {
+                        /* bottom pixel */
+                        int px2 = *(sbuf + (irv * sw) + uu);
+
+                        /* horizontal interpolate */
+                        if (iru < sw) {
+                            /* bottom right pixel */
+                            int px3 = *(sbuf + (irv * sw) + iru);
+                            px2 = INTERPOLATE(px2, px3, ar);
+                        }
+                        px = INTERPOLATE(px, px2, ab);
+                    }
+                    if (direct) {
+                        auto tmp = maskOp(px, *cmp, 0);  //not use alpha
+                        *dst = tmp + MULTIPLY(*dst, ~tmp);
+                        ++dst;
+                    } else {
+                        *cmp = maskOp(px, *cmp, ~px);
+                    }
+                    ++cmp;
+
+                    //Step UV horizontally
+                    u += _dudx;
+                    v += _dvdx;
+                    //range over?
+                    if ((uint32_t)v >= image->h) break;
+                }
+            } else {
+                //Draw horizontal line
+                while (x++ < x2) {
+                    uu = (int) u;
+                    if (uu >= sw) continue;
+                    vv = (int) v;
+                    if (vv >= sh) continue;
+
+                    ar = (int)(255 * (1 - modff(u, &iptr)));
+                    ab = (int)(255 * (1 - modff(v, &iptr)));
+                    iru = uu + 1;
+                    irv = vv + 1;
+
+                    px = *(sbuf + (vv * sw) + uu);
+
+                    /* horizontal interpolate */
+                    if (iru < sw) {
+                        /* right pixel */
+                        int px2 = *(sbuf + (vv * sw) + iru);
+                        px = INTERPOLATE(px, px2, ar);
+                    }
+                    /* vertical interpolate */
+                    if (irv < sh) {
+                        /* bottom pixel */
+                        int px2 = *(sbuf + (irv * sw) + uu);
+
+                        /* horizontal interpolate */
+                        if (iru < sw) {
+                            /* bottom right pixel */
+                            int px3 = *(sbuf + (irv * sw) + iru);
+                            px2 = INTERPOLATE(px2, px3, ar);
+                        }
+                        px = INTERPOLATE(px, px2, ab);
+                    }
+
+                    if (direct) {
+                        auto tmp = maskOp(MULTIPLY(px, opacity), *cmp, 0);
+                        *dst = tmp + MULTIPLY(*dst, ~tmp);
+                        ++dst;
+                    } else {
+                        auto tmp = MULTIPLY(px, opacity);
+                        *cmp = maskOp(tmp, *cmp, ~px);
+                    }
+                    ++cmp;
+
+                    //Step UV horizontally
+                    u += _dudx;
+                    v += _dvdx;
+                    //range over?
+                    if ((uint32_t)v >= image->h) break;
+                }
+            }
+        }
+
+        //Step along both edges
+        _xa += _dxdya;
+        _xb += _dxdyb;
+        _ua += _dudya;
+        _va += _dvdya;
+
+        if (!region && spanIdx >= image->rle->size) break;
+
+        ++y;
+    }
+    xa = _xa;
+    xb = _xb;
+    ua = _ua;
+    va = _va;
+
+    return true;
+#endif
+}
+
+
+static void _rasterBlendingPolygonImageSegment(SwSurface* surface, const SwImage* image, const SwBBox* region, int yStart, int yEnd, AASpans* aaSpans, uint8_t opacity)
+{
+    float _dudx = dudx, _dvdx = dvdx;
+    float _dxdya = dxdya, _dxdyb = dxdyb, _dudya = dudya, _dvdya = dvdya;
+    float _xa = xa, _xb = xb, _ua = ua, _va = va;
+    auto sbuf = image->buf32;
+    auto dbuf = surface->buf32;
+    int32_t sw = static_cast<int32_t>(image->stride);
+    int32_t sh = image->h;
+    int32_t dw = surface->stride;
+    int32_t x1, x2, x, y, ar, ab, iru, irv, px, ay;
+    int32_t vv = 0, uu = 0;
+    int32_t minx = INT32_MAX, maxx = INT32_MIN;
+    float dx, u, v, iptr;
+    uint32_t* buf;
+    SwSpan* span = nullptr;         //used only when rle based.
+
+    if (!_arrange(image, region, yStart, yEnd)) return;
+
+    //Loop through all lines in the segment
+    uint32_t spanIdx = 0;
+
+    if (region) {
+        minx = region->min.x;
+        maxx = region->max.x;
+    } else {
+        span = image->rle->spans;
+        while (span->y < yStart) {
+            ++span;
+            ++spanIdx;
+        }
+    }
+
+    y = yStart;
+
+    while (y < yEnd) {
+        x1 = (int32_t)_xa;
+        x2 = (int32_t)_xb;
+
+        if (!region) {
+            minx = INT32_MAX;
+            maxx = INT32_MIN;
+            //one single row, could be consisted of multiple spans.
+            while (span->y == y && spanIdx < image->rle->size) {
+                if (minx > span->x) minx = span->x;
+                if (maxx < span->x + span->len) maxx = span->x + span->len;
+                ++span;
+                ++spanIdx;
+            }
+        }
+        if (x1 < minx) x1 = minx;
+        if (x2 > maxx) x2 = maxx;
+
+        //Anti-Aliasing frames
+        ay = y - aaSpans->yStart;
+        if (aaSpans->lines[ay].x[0] > x1) aaSpans->lines[ay].x[0] = x1;
+        if (aaSpans->lines[ay].x[1] < x2) aaSpans->lines[ay].x[1] = x2;
+
+        //Range allowed
+        if ((x2 - x1) >= 1 && (x1 < maxx) && (x2 > minx)) {
+
+            //Perform subtexel pre-stepping on UV
+            dx = 1 - (_xa - x1);
+            u = _ua + dx * _dudx;
+            v = _va + dx * _dvdx;
+
+            buf = dbuf + ((y * dw) + x1);
+
+            x = x1;
+
+            if (opacity == 255) {
+                //Draw horizontal line
+                while (x++ < x2) {
+                    uu = (int) u;
+                    if (uu >= sw) continue;
+                    vv = (int) v;
+                    if (vv >= sh) continue;
+
+                    ar = (int)(255 * (1 - modff(u, &iptr)));
+                    ab = (int)(255 * (1 - modff(v, &iptr)));
+                    iru = uu + 1;
+                    irv = vv + 1;
+
+                    px = *(sbuf + (vv * sw) + uu);
+
+                    /* horizontal interpolate */
+                    if (iru < sw) {
+                        /* right pixel */
+                        int px2 = *(sbuf + (vv * sw) + iru);
+                        px = INTERPOLATE(px, px2, ar);
+                    }
+                    /* vertical interpolate */
+                    if (irv < sh) {
+                        /* bottom pixel */
+                        int px2 = *(sbuf + (irv * sw) + uu);
+
+                        /* horizontal interpolate */
+                        if (iru < sw) {
+                            /* bottom right pixel */
+                            int px3 = *(sbuf + (irv * sw) + iru);
+                            px2 = INTERPOLATE(px2, px3, ar);
+                        }
+                        px = INTERPOLATE(px, px2, ab);
+                    }
+                    *buf = surface->blender(px, *buf, IA(px));
+                    ++buf;
+
+                    //Step UV horizontally
+                    u += _dudx;
+                    v += _dvdx;
+                    //range over?
+                    if ((uint32_t)v >= image->h) break;
+                }
+            } else {
+                //Draw horizontal line
+                while (x++ < x2) {
+                    uu = (int) u;
+                    if (uu >= sw) continue;
+                    vv = (int) v;
+                    if (vv >= sh) continue;
+
+                    ar = (int)(255 * (1 - modff(u, &iptr)));
+                    ab = (int)(255 * (1 - modff(v, &iptr)));
+                    iru = uu + 1;
+                    irv = vv + 1;
+
+                    px = *(sbuf + (vv * sw) + uu);
+
+                    /* horizontal interpolate */
+                    if (iru < sw) {
+                        /* right pixel */
+                        int px2 = *(sbuf + (vv * sw) + iru);
+                        px = INTERPOLATE(px, px2, ar);
+                    }
+                    /* vertical interpolate */
+                    if (irv < sh) {
+                        /* bottom pixel */
+                        int px2 = *(sbuf + (irv * sw) + uu);
+
+                        /* horizontal interpolate */
+                        if (iru < sw) {
+                            /* bottom right pixel */
+                            int px3 = *(sbuf + (irv * sw) + iru);
+                            px2 = INTERPOLATE(px2, px3, ar);
+                        }
+                        px = INTERPOLATE(px, px2, ab);
+                    }
+                    auto src = ALPHA_BLEND(px, opacity);
+                    *buf = surface->blender(src, *buf, IA(src));
+                    ++buf;
+
+                    //Step UV horizontally
+                    u += _dudx;
+                    v += _dvdx;
+                    //range over?
+                    if ((uint32_t)v >= image->h) break;
+                }
+            }
+        }
+
+        //Step along both edges
+        _xa += _dxdya;
+        _xb += _dxdyb;
+        _ua += _dudya;
+        _va += _dvdya;
+
+        if (!region && spanIdx >= image->rle->size) break;
+
+        ++y;
+    }
+    xa = _xa;
+    xb = _xb;
+    ua = _ua;
+    va = _va;
+}
+
+
+static void _rasterPolygonImageSegment(SwSurface* surface, const SwImage* image, const SwBBox* region, int yStart, int yEnd, AASpans* aaSpans, uint8_t opacity, bool matting)
+{
+    float _dudx = dudx, _dvdx = dvdx;
+    float _dxdya = dxdya, _dxdyb = dxdyb, _dudya = dudya, _dvdya = dvdya;
+    float _xa = xa, _xb = xb, _ua = ua, _va = va;
+    auto sbuf = image->buf32;
+    auto dbuf = surface->buf32;
+    int32_t sw = static_cast<int32_t>(image->stride);
+    int32_t sh = image->h;
+    int32_t dw = surface->stride;
+    int32_t x1, x2, x, y, ar, ab, iru, irv, px, ay;
+    int32_t vv = 0, uu = 0;
+    int32_t minx = INT32_MAX, maxx = INT32_MIN;
+    float dx, u, v, iptr;
+    uint32_t* buf;
+    SwSpan* span = nullptr;         //used only when rle based.
+
+    //for matting(composition)
+    auto csize = matting ? surface->compositor->image.channelSize: 0;
+    auto alpha = matting ? surface->alpha(surface->compositor->method) : nullptr;
+    uint8_t* cmp = nullptr;
+
+    if (!_arrange(image, region, yStart, yEnd)) return;
+
+    //Loop through all lines in the segment
+    uint32_t spanIdx = 0;
+
+    if (region) {
+        minx = region->min.x;
+        maxx = region->max.x;
+    } else {
+        span = image->rle->spans;
+        while (span->y < yStart) {
+            ++span;
+            ++spanIdx;
+        }
+    }
+
+    y = yStart;
+
+    while (y < yEnd) {
+        x1 = (int32_t)_xa;
+        x2 = (int32_t)_xb;
+
+        if (!region) {
+            minx = INT32_MAX;
+            maxx = INT32_MIN;
+            //one single row, could be consisted of multiple spans.
+            while (span->y == y && spanIdx < image->rle->size) {
+                if (minx > span->x) minx = span->x;
+                if (maxx < span->x + span->len) maxx = span->x + span->len;
+                ++span;
+                ++spanIdx;
+            }
+        }
+        if (x1 < minx) x1 = minx;
+        if (x2 > maxx) x2 = maxx;
+
+        //Anti-Aliasing frames
+        ay = y - aaSpans->yStart;
+        if (aaSpans->lines[ay].x[0] > x1) aaSpans->lines[ay].x[0] = x1;
+        if (aaSpans->lines[ay].x[1] < x2) aaSpans->lines[ay].x[1] = x2;
+
+        //Range allowed
+        if ((x2 - x1) >= 1 && (x1 < maxx) && (x2 > minx)) {
+
+            //Perform subtexel pre-stepping on UV
+            dx = 1 - (_xa - x1);
+            u = _ua + dx * _dudx;
+            v = _va + dx * _dvdx;
+
+            buf = dbuf + ((y * dw) + x1);
+
+            x = x1;
+
+            if (matting) cmp = &surface->compositor->image.buf8[(y * surface->compositor->image.stride + x1) * csize];
+
+            if (opacity == 255) {
+                //Draw horizontal line
+                while (x++ < x2) {
+                    uu = (int) u;
+                    if (uu >= sw) continue;
+                    vv = (int) v;
+                    if (vv >= sh) continue;
+
+                    ar = (int)(255 * (1 - modff(u, &iptr)));
+                    ab = (int)(255 * (1 - modff(v, &iptr)));
+                    iru = uu + 1;
+                    irv = vv + 1;
+
+                    px = *(sbuf + (vv * sw) + uu);
+
+                    /* horizontal interpolate */
+                    if (iru < sw) {
+                        /* right pixel */
+                        int px2 = *(sbuf + (vv * sw) + iru);
+                        px = INTERPOLATE(px, px2, ar);
+                    }
+                    /* vertical interpolate */
+                    if (irv < sh) {
+                        /* bottom pixel */
+                        int px2 = *(sbuf + (irv * sw) + uu);
+
+                        /* horizontal interpolate */
+                        if (iru < sw) {
+                            /* bottom right pixel */
+                            int px3 = *(sbuf + (irv * sw) + iru);
+                            px2 = INTERPOLATE(px2, px3, ar);
+                        }
+                        px = INTERPOLATE(px, px2, ab);
+                    }
+                    uint32_t src;
+                    if (matting) {
+                        src = ALPHA_BLEND(px, alpha(cmp));
+                        cmp += csize;
+                    } else {
+                        src = px;
+                    }
+                    *buf = src + ALPHA_BLEND(*buf, IA(src));
+                    ++buf;
+
+                    //Step UV horizontally
+                    u += _dudx;
+                    v += _dvdx;
+                    //range over?
+                    if ((uint32_t)v >= image->h) break;
+                }
+            } else {
+                //Draw horizontal line
+                while (x++ < x2) {
+                    uu = (int) u;
+                    vv = (int) v;
+
+                    ar = (int)(255 * (1 - modff(u, &iptr)));
+                    ab = (int)(255 * (1 - modff(v, &iptr)));
+                    iru = uu + 1;
+                    irv = vv + 1;
+
+                    if (vv >= sh) continue;
+
+                    px = *(sbuf + (vv * sw) + uu);
+
+                    /* horizontal interpolate */
+                    if (iru < sw) {
+                        /* right pixel */
+                        int px2 = *(sbuf + (vv * sw) + iru);
+                        px = INTERPOLATE(px, px2, ar);
+                    }
+                    /* vertical interpolate */
+                    if (irv < sh) {
+                        /* bottom pixel */
+                        int px2 = *(sbuf + (irv * sw) + uu);
+
+                        /* horizontal interpolate */
+                        if (iru < sw) {
+                            /* bottom right pixel */
+                            int px3 = *(sbuf + (irv * sw) + iru);
+                            px2 = INTERPOLATE(px2, px3, ar);
+                        }
+                        px = INTERPOLATE(px, px2, ab);
+                    }
+                    uint32_t src;
+                    if (matting) {
+                        src = ALPHA_BLEND(px, MULTIPLY(opacity, alpha(cmp)));
+                        cmp += csize;
+                    } else {
+                        src = ALPHA_BLEND(px, opacity);
+                    }
+                    *buf = src + ALPHA_BLEND(*buf, IA(src));
+                    ++buf;
+
+                    //Step UV horizontally
+                    u += _dudx;
+                    v += _dvdx;
+                    //range over?
+                    if ((uint32_t)v >= image->h) break;
+                }
+            }
+        }
+
+        //Step along both edges
+        _xa += _dxdya;
+        _xb += _dxdyb;
+        _ua += _dudya;
+        _va += _dvdya;
+
+        if (!region && spanIdx >= image->rle->size) break;
+
+        ++y;
+    }
+    xa = _xa;
+    xb = _xb;
+    ua = _ua;
+    va = _va;
+}
+
+
+/* This mapping algorithm is based on Mikael Kalms's. */
+static void _rasterPolygonImage(SwSurface* surface, const SwImage* image, const SwBBox* region, Polygon& polygon, AASpans* aaSpans, uint8_t opacity)
+{
+    float x[3] = {polygon.vertex[0].pt.x, polygon.vertex[1].pt.x, polygon.vertex[2].pt.x};
+    float y[3] = {polygon.vertex[0].pt.y, polygon.vertex[1].pt.y, polygon.vertex[2].pt.y};
+    float u[3] = {polygon.vertex[0].uv.x, polygon.vertex[1].uv.x, polygon.vertex[2].uv.x};
+    float v[3] = {polygon.vertex[0].uv.y, polygon.vertex[1].uv.y, polygon.vertex[2].uv.y};
+
+    float off_y;
+    float dxdy[3] = {0.0f, 0.0f, 0.0f};
+    float tmp;
+
+    auto upper = false;
+
+    //Sort the vertices in ascending Y order
+    if (y[0] > y[1]) {
+        _swap(x[0], x[1], tmp);
+        _swap(y[0], y[1], tmp);
+        _swap(u[0], u[1], tmp);
+        _swap(v[0], v[1], tmp);
+    }
+    if (y[0] > y[2])  {
+        _swap(x[0], x[2], tmp);
+        _swap(y[0], y[2], tmp);
+        _swap(u[0], u[2], tmp);
+        _swap(v[0], v[2], tmp);
+    }
+    if (y[1] > y[2]) {
+        _swap(x[1], x[2], tmp);
+        _swap(y[1], y[2], tmp);
+        _swap(u[1], u[2], tmp);
+        _swap(v[1], v[2], tmp);
+    }
+
+    //Y indexes
+    int yi[3] = {(int)y[0], (int)y[1], (int)y[2]};
+
+    //Skip drawing if it's too thin to cover any pixels at all.
+    if ((yi[0] == yi[1] && yi[0] == yi[2]) || ((int) x[0] == (int) x[1] && (int) x[0] == (int) x[2])) return;
+
+    //Calculate horizontal and vertical increments for UV axes (these calcs are certainly not optimal, although they're stable (handles any dy being 0)
+    auto denom = ((x[2] - x[0]) * (y[1] - y[0]) - (x[1] - x[0]) * (y[2] - y[0]));
+
+    //Skip poly if it's an infinitely thin line
+    if (mathZero(denom)) return;
+
+    denom = 1 / denom;   //Reciprocal for speeding up
+    dudx = ((u[2] - u[0]) * (y[1] - y[0]) - (u[1] - u[0]) * (y[2] - y[0])) * denom;
+    dvdx = ((v[2] - v[0]) * (y[1] - y[0]) - (v[1] - v[0]) * (y[2] - y[0])) * denom;
+    auto dudy = ((u[1] - u[0]) * (x[2] - x[0]) - (u[2] - u[0]) * (x[1] - x[0])) * denom;
+    auto dvdy = ((v[1] - v[0]) * (x[2] - x[0]) - (v[2] - v[0]) * (x[1] - x[0])) * denom;
+
+    //Calculate X-slopes along the edges
+    if (y[1] > y[0]) dxdy[0] = (x[1] - x[0]) / (y[1] - y[0]);
+    if (y[2] > y[0]) dxdy[1] = (x[2] - x[0]) / (y[2] - y[0]);
+    if (y[2] > y[1]) dxdy[2] = (x[2] - x[1]) / (y[2] - y[1]);
+
+    //Determine which side of the polygon the longer edge is on
+    auto side = (dxdy[1] > dxdy[0]) ? true : false;
+
+    if (mathEqual(y[0], y[1])) side = x[0] > x[1];
+    if (mathEqual(y[1], y[2])) side = x[2] > x[1];
+
+    auto regionTop = region ? region->min.y : image->rle->spans->y;  //Normal Image or Rle Image?
+    auto compositing = _compositing(surface);   //Composition required
+    auto blending = _blending(surface);         //Blending required
+
+    //Longer edge is on the left side
+    if (!side) {
+        //Calculate slopes along left edge
+        dxdya = dxdy[1];
+        dudya = dxdya * dudx + dudy;
+        dvdya = dxdya * dvdx + dvdy;
+
+        //Perform subpixel pre-stepping along left edge
+        auto dy = 1.0f - (y[0] - yi[0]);
+        xa = x[0] + dy * dxdya;
+        ua = u[0] + dy * dudya;
+        va = v[0] + dy * dvdya;
+
+        //Draw upper segment if possibly visible
+        if (yi[0] < yi[1]) {
+            off_y = y[0] < regionTop ? (regionTop - y[0]) : 0;
+            xa += (off_y * dxdya);
+            ua += (off_y * dudya);
+            va += (off_y * dvdya);
+
+            // Set right edge X-slope and perform subpixel pre-stepping
+            dxdyb = dxdy[0];
+            xb = x[0] + dy * dxdyb + (off_y * dxdyb);
+
+            if (compositing) {
+                if (_matting(surface)) _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans, opacity, true);
+                else _rasterMaskedPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans, opacity, 1);
+            } else if (blending) {
+                _rasterBlendingPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans, opacity);
+            } else {
+                _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans, opacity, false);
+            }
+            upper = true;
+        }
+        //Draw lower segment if possibly visible
+        if (yi[1] < yi[2]) {
+            off_y = y[1] < regionTop ? (regionTop - y[1]) : 0;
+            if (!upper) {
+                xa += (off_y * dxdya);
+                ua += (off_y * dudya);
+                va += (off_y * dvdya);
+            }
+            // Set right edge X-slope and perform subpixel pre-stepping
+            dxdyb = dxdy[2];
+            xb = x[1] + (1 - (y[1] - yi[1])) * dxdyb + (off_y * dxdyb);
+            if (compositing) {
+                if (_matting(surface)) _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans, opacity, true);
+                else _rasterMaskedPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans, opacity, 2);
+            } else if (blending) {
+                 _rasterBlendingPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans, opacity);
+            } else {
+                _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans, opacity, false);
+            }
+        }
+    //Longer edge is on the right side
+    } else {
+        //Set right edge X-slope and perform subpixel pre-stepping
+        dxdyb = dxdy[1];
+        auto dy = 1.0f - (y[0] - yi[0]);
+        xb = x[0] + dy * dxdyb;
+
+        //Draw upper segment if possibly visible
+        if (yi[0] < yi[1]) {
+            off_y = y[0] < regionTop ? (regionTop - y[0]) : 0;
+            xb += (off_y *dxdyb);
+
+            // Set slopes along left edge and perform subpixel pre-stepping
+            dxdya = dxdy[0];
+            dudya = dxdya * dudx + dudy;
+            dvdya = dxdya * dvdx + dvdy;
+
+            xa = x[0] + dy * dxdya + (off_y * dxdya);
+            ua = u[0] + dy * dudya + (off_y * dudya);
+            va = v[0] + dy * dvdya + (off_y * dvdya);
+
+            if (compositing) {
+                if (_matting(surface)) _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans, opacity, true);
+                else _rasterMaskedPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans, opacity, 3);
+            } else if (blending) {
+                _rasterBlendingPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans, opacity);
+            } else {
+                _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans, opacity, false);
+            }
+            upper = true;
+        }
+        //Draw lower segment if possibly visible
+        if (yi[1] < yi[2]) {
+            off_y = y[1] < regionTop ? (regionTop - y[1]) : 0;
+            if (!upper) xb += (off_y *dxdyb);
+
+            // Set slopes along left edge and perform subpixel pre-stepping
+            dxdya = dxdy[2];
+            dudya = dxdya * dudx + dudy;
+            dvdya = dxdya * dvdx + dvdy;
+            dy = 1 - (y[1] - yi[1]);
+            xa = x[1] + dy * dxdya + (off_y * dxdya);
+            ua = u[1] + dy * dudya + (off_y * dudya);
+            va = v[1] + dy * dvdya + (off_y * dvdya);
+
+            if (compositing) {
+                if (_matting(surface)) _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans, opacity, true);
+                else _rasterMaskedPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans, opacity, 4);
+            } else if (blending) {
+                _rasterBlendingPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans, opacity);
+            } else {
+                _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans, opacity, false);
+            }
+        }
+    }
+}
+
+
+static AASpans* _AASpans(float ymin, float ymax, const SwImage* image, const SwBBox* region)
+{
+    auto yStart = static_cast<int32_t>(ymin);
+    auto yEnd = static_cast<int32_t>(ymax);
+
+    if (!_arrange(image, region, yStart, yEnd)) return nullptr;
+
+    auto aaSpans = static_cast<AASpans*>(malloc(sizeof(AASpans)));
+    aaSpans->yStart = yStart;
+    aaSpans->yEnd = yEnd;
+
+    //Initialize X range
+    auto height = yEnd - yStart;
+
+    aaSpans->lines = static_cast<AALine*>(calloc(height, sizeof(AALine)));
+
+    for (int32_t i = 0; i < height; i++) {
+        aaSpans->lines[i].x[0] = INT32_MAX;
+        aaSpans->lines[i].x[1] = INT32_MIN;
+    }
+    return aaSpans;
+}
+
+
+static void _calcIrregularCoverage(AALine* lines, int32_t eidx, int32_t y, int32_t diagonal, int32_t edgeDist, bool reverse)
+{
+    if (eidx == 1) reverse = !reverse;
+    int32_t coverage = (255 / (diagonal + 2));
+    int32_t tmp;
+    for (int32_t ry = 0; ry < (diagonal + 2); ry++) {
+        tmp = y - ry - edgeDist;
+        if (tmp < 0) return;
+        lines[tmp].length[eidx] = 1;
+        if (reverse) lines[tmp].coverage[eidx] = 255 - (coverage * ry);
+        else lines[tmp].coverage[eidx] = (coverage * ry);
+    }
+}
+
+
+static void _calcVertCoverage(AALine *lines, int32_t eidx, int32_t y, int32_t rewind, bool reverse)
+{
+    if (eidx == 1) reverse = !reverse;
+    int32_t coverage = (255 / (rewind + 1));
+    int32_t tmp;
+    for (int ry = 1; ry < (rewind + 1); ry++) {
+        tmp = y - ry;
+        if (tmp < 0) return;
+        lines[tmp].length[eidx] = 1;
+        if (reverse) lines[tmp].coverage[eidx] = (255 - (coverage * ry));
+        else lines[tmp].coverage[eidx] = (coverage * ry);
+    }
+}
+
+
+static void _calcHorizCoverage(AALine *lines, int32_t eidx, int32_t y, int32_t x, int32_t x2)
+{
+    if (lines[y].length[eidx] < abs(x - x2)) {
+        lines[y].length[eidx] = abs(x - x2);
+        lines[y].coverage[eidx] = (255 / (lines[y].length[eidx] + 1));
+    }
+}
+
+
+/*
+ * This Anti-Aliasing mechanism is originated from Hermet Park's idea.
+ * To understand this AA logic, you can refer this page:
+ * www.hermet.pe.kr/122 (hermetpark@gmail.com)
+*/
+static void _calcAAEdge(AASpans *aaSpans, int32_t eidx)
+{
+//Previous edge direction:
+#define DirOutHor 0x0011
+#define DirOutVer 0x0001
+#define DirInHor  0x0010
+#define DirInVer  0x0000
+#define DirNone   0x1000
+
+#define PUSH_VERTEX() \
+    do { \
+        pEdge.x = lines[y].x[eidx]; \
+        pEdge.y = y; \
+        ptx[0] = tx[0]; \
+        ptx[1] = tx[1]; \
+    } while (0)
+
+    int32_t y = 0;
+    SwPoint pEdge = {-1, -1};       //previous edge point
+    SwPoint edgeDiff = {0, 0};      //temporary used for point distance
+
+    /* store bigger to tx[0] between prev and current edge's x positions. */
+    int32_t tx[2] = {0, 0};
+    /* back up prev tx values */
+    int32_t ptx[2] = {0, 0};
+    int32_t diagonal = 0;           //straight diagonal pixels count
+
+    auto yStart = aaSpans->yStart;
+    auto yEnd = aaSpans->yEnd;
+    auto lines = aaSpans->lines;
+
+    int32_t prevDir = DirNone;
+    int32_t curDir = DirNone;
+
+    yEnd -= yStart;
+
+    //Start Edge
+    if (y < yEnd) {
+        pEdge.x = lines[y].x[eidx];
+        pEdge.y = y;
+    }
+
+    //Calculates AA Edges
+    for (y++; y < yEnd; y++) {
+        //Ready tx
+        if (eidx == 0) {
+            tx[0] = pEdge.x;
+            tx[1] = lines[y].x[0];
+        } else {
+            tx[0] = lines[y].x[1];
+            tx[1] = pEdge.x;
+        }
+        edgeDiff.x = (tx[0] - tx[1]);
+        edgeDiff.y = (y - pEdge.y);
+
+        //Confirm current edge direction
+        if (edgeDiff.x > 0) {
+            if (edgeDiff.y == 1) curDir = DirOutHor;
+            else curDir = DirOutVer;
+        } else if (edgeDiff.x < 0) {
+            if (edgeDiff.y == 1) curDir = DirInHor;
+            else curDir = DirInVer;
+        } else curDir = DirNone;
+
+        //straight diagonal increase
+        if ((curDir == prevDir) && (y < yEnd)) {
+            if ((abs(edgeDiff.x) == 1) && (edgeDiff.y == 1)) {
+                ++diagonal;
+                PUSH_VERTEX();
+                continue;
+            }
+        }
+
+        switch (curDir) {
+            case DirOutHor: {
+                _calcHorizCoverage(lines, eidx, y, tx[0], tx[1]);
+                if (diagonal > 0) {
+                    _calcIrregularCoverage(lines, eidx, y, diagonal, 0, true);
+                    diagonal = 0;
+                }
+               /* Increment direction is changed: Outside Vertical -> Outside Horizontal */
+               if (prevDir == DirOutVer) _calcHorizCoverage(lines, eidx, pEdge.y, ptx[0], ptx[1]);
+
+               //Trick, but fine-tunning!
+               if (y == 1) _calcHorizCoverage(lines, eidx, pEdge.y, tx[0], tx[1]);
+               PUSH_VERTEX();
+            }
+            break;
+            case DirOutVer: {
+                _calcVertCoverage(lines, eidx, y, edgeDiff.y, true);
+                if (diagonal > 0) {
+                    _calcIrregularCoverage(lines, eidx, y, diagonal, edgeDiff.y, false);
+                    diagonal = 0;
+                }
+               /* Increment direction is changed: Outside Horizontal -> Outside Vertical */
+               if (prevDir == DirOutHor) _calcHorizCoverage(lines, eidx, pEdge.y, ptx[0], ptx[1]);
+               PUSH_VERTEX();
+            }
+            break;
+            case DirInHor: {
+                _calcHorizCoverage(lines, eidx, (y - 1), tx[0], tx[1]);
+                if (diagonal > 0) {
+                    _calcIrregularCoverage(lines, eidx, y, diagonal, 0, false);
+                    diagonal = 0;
+                }
+                /* Increment direction is changed: Outside Horizontal -> Inside Horizontal */
+               if (prevDir == DirOutHor) _calcHorizCoverage(lines, eidx, pEdge.y, ptx[0], ptx[1]);
+               PUSH_VERTEX();
+            }
+            break;
+            case DirInVer: {
+                _calcVertCoverage(lines, eidx, y, edgeDiff.y, false);
+                if (prevDir == DirOutHor) edgeDiff.y -= 1;      //Weird, fine tuning?????????????????????
+                if (diagonal > 0) {
+                    _calcIrregularCoverage(lines, eidx, y, diagonal, edgeDiff.y, true);
+                    diagonal = 0;
+                }
+                /* Increment direction is changed: Outside Horizontal -> Inside Vertical */
+                if (prevDir == DirOutHor) _calcHorizCoverage(lines, eidx, pEdge.y, ptx[0], ptx[1]);
+                PUSH_VERTEX();
+            }
+            break;
+        }
+        if (curDir != DirNone) prevDir = curDir;
+    }
+
+    //leftovers...?
+    if ((edgeDiff.y == 1) && (edgeDiff.x != 0)) {
+        if (y >= yEnd) y = (yEnd - 1);
+        _calcHorizCoverage(lines, eidx, y - 1, ptx[0], ptx[1]);
+        _calcHorizCoverage(lines, eidx, y, tx[0], tx[1]);
+    } else {
+        ++y;
+        if (y > yEnd) y = yEnd;
+        _calcVertCoverage(lines, eidx, y, (edgeDiff.y + 1), (prevDir & 0x00000001));
+    }
+}
+
+
+static bool _apply(SwSurface* surface, AASpans* aaSpans)
+{
+    auto y = aaSpans->yStart;
+    uint32_t pixel;
+    uint32_t* dst;
+    int32_t pos;
+
+   //left side
+   _calcAAEdge(aaSpans, 0);
+   //right side
+   _calcAAEdge(aaSpans, 1);
+
+    while (y < aaSpans->yEnd) {
+        auto line = &aaSpans->lines[y - aaSpans->yStart];
+        auto width = line->x[1] - line->x[0];
+        if (width > 0) {
+            auto offset = y * surface->stride;
+
+            //Left edge
+            dst = surface->buf32 + (offset + line->x[0]);
+            if (line->x[0] > 1) pixel = *(dst - 1);
+            else pixel = *dst;
+
+            pos = 1;
+            while (pos <= line->length[0]) {
+                *dst = INTERPOLATE(*dst, pixel, line->coverage[0] * pos);
+                ++dst;
+                ++pos;
+            }
+
+            //Right edge
+            dst = surface->buf32 + (offset + line->x[1] - 1);
+            if (line->x[1] < (int32_t)(surface->w - 1)) pixel = *(dst + 1);
+            else pixel = *dst;
+
+            pos = width;
+            while ((int32_t)(width - line->length[1]) < pos) {
+                *dst = INTERPOLATE(*dst, pixel, 255 - (line->coverage[1] * (line->length[1] - (width - pos))));
+                --dst;
+                --pos;
+            }
+          }
+        y++;
+    }
+
+    free(aaSpans->lines);
+    free(aaSpans);
+
+    return true;
+}
+
+
+/*
+    2 triangles constructs 1 mesh.
+    below figure illustrates vert[4] index info.
+    If you need better quality, please divide a mesh by more number of triangles.
+
+    0 -- 1
+    |  / |
+    | /  |
+    3 -- 2
+*/
+static bool _rasterTexmapPolygon(SwSurface* surface, const SwImage* image, const Matrix* transform, const SwBBox* region, uint8_t opacity)
+{
+    if (surface->channelSize == sizeof(uint8_t)) {
+        TVGERR("SW_ENGINE", "Not supported grayscale Textmap polygon!");
+        return false;
+    }
+
+    //Exceptions: No dedicated drawing area?
+    if ((!image->rle && !region) || (image->rle && image->rle->size == 0)) return false;
+
+   /* Prepare vertices.
+      shift XY coordinates to match the sub-pixeling technique. */
+    Vertex vertices[4];
+    vertices[0] = {{0.0f, 0.0f}, {0.0f, 0.0f}};
+    vertices[1] = {{float(image->w), 0.0f}, {float(image->w), 0.0f}};
+    vertices[2] = {{float(image->w), float(image->h)}, {float(image->w), float(image->h)}};
+    vertices[3] = {{0.0f, float(image->h)}, {0.0f, float(image->h)}};
+
+    float ys = FLT_MAX, ye = -1.0f;
+    for (int i = 0; i < 4; i++) {
+        mathMultiply(&vertices[i].pt, transform);
+
+        if (vertices[i].pt.y < ys) ys = vertices[i].pt.y;
+        if (vertices[i].pt.y > ye) ye = vertices[i].pt.y;
+    }
+
+    auto aaSpans = _AASpans(ys, ye, image, region);
+    if (!aaSpans) return true;
+
+    Polygon polygon;
+
+    //Draw the first polygon
+    polygon.vertex[0] = vertices[0];
+    polygon.vertex[1] = vertices[1];
+    polygon.vertex[2] = vertices[3];
+
+    _rasterPolygonImage(surface, image, region, polygon, aaSpans, opacity);
+
+    //Draw the second polygon
+    polygon.vertex[0] = vertices[1];
+    polygon.vertex[1] = vertices[2];
+    polygon.vertex[2] = vertices[3];
+
+    _rasterPolygonImage(surface, image, region, polygon, aaSpans, opacity);
+
+#if 0
+    if (_compositing(surface) && _masking(surface) && !_direct(surface->compositor->method)) {
+        _compositeMaskImage(surface, &surface->compositor->image, surface->compositor->bbox);
+    }
+#endif
+    return _apply(surface, aaSpans);
+}
+
+
+/*
+    Provide any number of triangles to draw a mesh using the supplied image.
+    Indexes are not used, so each triangle (Polygon) vertex has to be defined, even if they copy the previous one.
+    Example:
+
+      0 -- 1       0 -- 1   0
+      |  / |  -->  |  /   / |
+      | /  |       | /   /  |
+      2 -- 3       2   1 -- 2
+
+      Should provide two Polygons, one for each triangle.
+      // TODO: region?
+*/
+static bool _rasterTexmapPolygonMesh(SwSurface* surface, const SwImage* image, const RenderMesh* mesh, const Matrix* transform, const SwBBox* region, uint8_t opacity)
+{
+    if (surface->channelSize == sizeof(uint8_t)) {
+        TVGERR("SW_ENGINE", "Not supported grayscale Textmap polygon mesh!");
+        return false;
+    }
+
+    //Exceptions: No dedicated drawing area?
+    if ((!image->rle && !region) || (image->rle && image->rle->size == 0)) return false;
+
+    // Step polygons once to transform
+    auto transformedTris = (Polygon*)malloc(sizeof(Polygon) * mesh->triangleCnt);
+    float ys = FLT_MAX, ye = -1.0f;
+    for (uint32_t i = 0; i < mesh->triangleCnt; i++) {
+        transformedTris[i] = mesh->triangles[i];
+        mathMultiply(&transformedTris[i].vertex[0].pt, transform);
+        mathMultiply(&transformedTris[i].vertex[1].pt, transform);
+        mathMultiply(&transformedTris[i].vertex[2].pt, transform);
+
+        if (transformedTris[i].vertex[0].pt.y < ys) ys = transformedTris[i].vertex[0].pt.y;
+        else if (transformedTris[i].vertex[0].pt.y > ye) ye = transformedTris[i].vertex[0].pt.y;
+        if (transformedTris[i].vertex[1].pt.y < ys) ys = transformedTris[i].vertex[1].pt.y;
+        else if (transformedTris[i].vertex[1].pt.y > ye) ye = transformedTris[i].vertex[1].pt.y;
+        if (transformedTris[i].vertex[2].pt.y < ys) ys = transformedTris[i].vertex[2].pt.y;
+        else if (transformedTris[i].vertex[2].pt.y > ye) ye = transformedTris[i].vertex[2].pt.y;
+
+        // Convert normalized UV coordinates to image coordinates
+        transformedTris[i].vertex[0].uv.x *= (float)image->w;
+        transformedTris[i].vertex[0].uv.y *= (float)image->h;
+        transformedTris[i].vertex[1].uv.x *= (float)image->w;
+        transformedTris[i].vertex[1].uv.y *= (float)image->h;
+        transformedTris[i].vertex[2].uv.x *= (float)image->w;
+        transformedTris[i].vertex[2].uv.y *= (float)image->h;
+    }
+
+    // Get AA spans and step polygons again to draw
+    if (auto aaSpans = _AASpans(ys, ye, image, region)) {
+        for (uint32_t i = 0; i < mesh->triangleCnt; i++) {
+            _rasterPolygonImage(surface, image, region, transformedTris[i], aaSpans, opacity);
+        }
+#if 0
+        if (_compositing(surface) && _masking(surface) && !_direct(surface->compositor->method)) {
+            _compositeMaskImage(surface, &surface->compositor->image, surface->compositor->bbox);
+        }
+#endif
+        _apply(surface, aaSpans);
+    }
+    free(transformedTris);
+    return true;
+}