/* * 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 void _rasterPolygonImageSegment(SwSurface* surface, const SwImage* image, const SwBBox* region, int yStart, int yEnd, uint32_t opacity, uint8_t(*blender)(uint8_t*), AASpans* aaSpans) { #define TEXMAP_TRANSLUCENT #define TEXMAP_MASKING #include "tvgSwRasterTexmapInternal.h" #undef TEXMAP_MASKING #undef TEXMAP_TRANSLUCENT } static void _rasterPolygonImageSegment(SwSurface* surface, const SwImage* image, const SwBBox* region, int yStart, int yEnd, uint8_t(*blender)(uint8_t*), AASpans* aaSpans) { #define TEXMAP_MASKING #include "tvgSwRasterTexmapInternal.h" #undef TEXMAP_MASKING } static void _rasterPolygonImageSegment(SwSurface* surface, const SwImage* image, const SwBBox* region, int yStart, int yEnd, uint32_t opacity, AASpans* aaSpans) { #define TEXMAP_TRANSLUCENT #include "tvgSwRasterTexmapInternal.h" #undef TEXMAP_TRANSLUCENT } static void _rasterPolygonImageSegment(SwSurface* surface, const SwImage* image, const SwBBox* region, int yStart, int yEnd, AASpans* aaSpans) { #include "tvgSwRasterTexmapInternal.h" } /* This mapping algorithm is based on Mikael Kalms's. */ static void _rasterPolygonImage(SwSurface* surface, const SwImage* image, const SwBBox* region, uint32_t opacity, Polygon& polygon, uint8_t(*blender)(uint8_t*), AASpans* aaSpans) { 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? //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 (blender) { if (opacity == 255) _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], blender, aaSpans); else _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], opacity, blender, aaSpans); } else { if (opacity == 255) _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans); else _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], opacity, aaSpans); } 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 (blender) { if (opacity == 255) _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], blender, aaSpans); else _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], opacity, blender, aaSpans); } else { if (opacity == 255) _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans); else _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], opacity, aaSpans); } } //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 (blender) { if (opacity == 255) _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], blender, aaSpans); else _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], opacity, blender, aaSpans); } else { if (opacity == 255) _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], aaSpans); else _rasterPolygonImageSegment(surface, image, region, yi[0], yi[1], opacity, aaSpans); } 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 (blender) { if (opacity == 255) _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], blender, aaSpans); else _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], opacity, blender, aaSpans); } else { if (opacity == 255) _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], aaSpans); else _rasterPolygonImageSegment(surface, image, region, yi[1], yi[2], opacity, aaSpans); } } } } static AASpans* _AASpans(float ymin, float ymax, const SwImage* image, const SwBBox* region) { auto yStart = static_cast(ymin); auto yEnd = static_cast(ymax); if (!_arrange(image, region, yStart, yEnd)) return nullptr; auto aaSpans = static_cast(malloc(sizeof(AASpans))); aaSpans->yStart = yStart; aaSpans->yEnd = yEnd; //Initialize X range auto height = yEnd - yStart; aaSpans->lines = static_cast(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((line->coverage[0] * pos), *dst, pixel); ++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(255 - (line->coverage[1] * (line->length[1] - (width - pos))), *dst, pixel); --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, uint32_t opacity, uint8_t(*blender)(uint8_t*)) { //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, opacity, polygon, blender, aaSpans); //Draw the second polygon polygon.vertex[0] = vertices[1]; polygon.vertex[1] = vertices[2]; polygon.vertex[2] = vertices[3]; _rasterPolygonImage(surface, image, region, opacity, polygon, blender, aaSpans); 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, uint32_t opacity, uint8_t(*blender)(uint8_t*)) { //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 auto aaSpans = _AASpans(ys, ye, image, region); if (aaSpans) { for (uint32_t i = 0; i < mesh->triangleCnt; i++) { _rasterPolygonImage(surface, image, region, opacity, transformedTris[i], blender, aaSpans); } // Apply to surface (note: frees the AA spans) _apply(surface, aaSpans); } free(transformedTris); return true; }