Initial version of sl1 import with sla::Raster refactor.

src/libslic3r/SLA/RasterToPolygons.cpp

@@ -0,0 +1,88 @@
+#include "RasterToPolygons.hpp"
+
+#include "AGGRaster.hpp"
+#include "libslic3r/MarchingSquares.hpp"
+#include "MTUtils.hpp"
+#include "ClipperUtils.hpp"
+
+namespace marchsq {
+
+// Specialize this struct to register a raster type for the Marching squares alg
+template<> struct _RasterTraits<Slic3r::sla::RasterGrayscaleAA> {
+    using Rst = Slic3r::sla::RasterGrayscaleAA;
+    
+    // The type of pixel cell in the raster
+    using ValueType = uint8_t;
+    
+    // Value at a given position
+    static uint8_t get(const Rst &rst, size_t row, size_t col) { return rst.read_pixel(col, row); }
+    
+    // Number of rows and cols of the raster
+    static size_t rows(const Rst &rst) { return rst.resolution().height_px; }
+    static size_t cols(const Rst &rst) { return rst.resolution().width_px; }
+};
+
+} // namespace Slic3r::marchsq
+
+namespace Slic3r { namespace sla {
+
+template<class Fn> void foreach_vertex(ExPolygon &poly, Fn &&fn)
+{
+    for (auto &p : poly.contour.points) fn(p);
+    for (auto &h : poly.holes)
+        for (auto &p : h.points) fn(p);
+}
+
+ExPolygons raster_to_polygons(const RasterGrayscaleAA &rst, float accuracy)
+{    
+    size_t rows = rst.resolution().height_px, cols = rst.resolution().width_px;
+    
+    if (rows < 2 || cols < 2) return {};
+    
+    Polygons polys;
+    size_t w_rows = (2 + rows / 8) - size_t(accuracy * rows / 8);
+    size_t w_cols = std::max(size_t(2), w_rows * cols / rows);
+    
+    std::vector<marchsq::Ring> rings =
+        marchsq::execute(rst, 128, {w_rows, w_cols});
+    
+    polys.reserve(rings.size());
+    
+    auto pxd = rst.pixel_dimensions();
+    for (const marchsq::Ring &ring : rings) {
+        Polygon poly; Points &pts = poly.points;
+        pts.reserve(ring.size());
+        
+        for (const marchsq::Coord &crd : ring)
+            pts.emplace_back(scaled(crd.c * pxd.w_mm), scaled(crd.r * pxd.h_mm));
+        
+        polys.emplace_back(poly);
+    }
+    
+    // reverse the raster transformations
+    ExPolygons unioned = union_ex(polys);
+    coord_t width = scaled(cols * pxd.h_mm), height = scaled(rows * pxd.w_mm);
+    
+    auto tr = rst.trafo();
+    for (ExPolygon &expoly : unioned) {
+        if (tr.mirror_y)
+            foreach_vertex(expoly, [height](Point &p) {p.y() = height - p.y(); });
+        
+        if (tr.mirror_x)
+            foreach_vertex(expoly, [width](Point &p) {p.x() = width - p.x(); });
+        
+        expoly.translate(-tr.center_x, -tr.center_y);
+        
+        if (tr.flipXY)
+            foreach_vertex(expoly, [](Point &p) { std::swap(p.x(), p.y()); });
+        
+        if ((tr.mirror_x + tr.mirror_y + tr.flipXY) % 2) {
+            expoly.contour.reverse();
+            for (auto &h : expoly.holes) h.reverse();
+        }
+    }
+    
+    return unioned;
+}
+
+}} // namespace Slic3r