Partial emboss

src/libslic3r/Emboss.cpp

@@ -0,0 +1,111 @@
+#include "Emboss.hpp"
+#include <stdio.h>
+
+#define STB_TRUETYPE_IMPLEMENTATION // force following include to generate implementation
+#include "imgui/imstb_truetype.h" // stbtt_fontinfo
+
+using namespace Slic3r;
+
+std::optional<Emboss::Font> Emboss::load_font(const char *file_path)
+{
+    FILE *file = fopen(file_path, "rb");
+    if (file == nullptr) {
+        std::cerr << "Couldn't open " << file_path << " for reading.";
+        return {};
+    }
+
+    // find size of file
+    if (fseek(file, 0L, SEEK_END) != 0) {
+        std::cerr << "Couldn't fseek file " << file_path << " for size measure.";
+        return {};
+    }
+    size_t size = ftell(file);
+    if (size == 0) {
+        std::cerr << "Size of font file is zero. Can't read.";
+        return {};    
+    }
+    rewind(file);
+
+    Font res;
+    res.buffer = std::vector<unsigned char>(size);
+    size_t count_loaded_bytes = fread((void *) &res.buffer.front(), 1, size, file);
+
+    unsigned int index = 0;
+    int font_offset = 0;
+    while (font_offset >= 0) {
+        font_offset = stbtt_GetFontOffsetForIndex(res.buffer.data(), index++);
+    }
+    // at least one font must be inside collection
+    if (index < 1) {
+        std::cerr << "There is no font collection inside file.";
+        return {};        
+    }
+    // select default font on index 0
+    res.index = 0;
+    res.count = index;
+    // first fonst has offset zero
+    font_offset = 0;
+
+    stbtt_fontinfo font_info;
+    if (stbtt_InitFont(&font_info, res.buffer.data(), font_offset) == 0) {
+        std::cerr << "Can't initialize font.";
+        return {};    
+    }
+
+    // load information about line gap
+    stbtt_GetFontVMetrics(&(font_info), &res.ascent, &res.descent, &res.linegap);
+    return res;
+}
+
+Polygons Emboss::letter2polygons(const Font &font, char letter)
+{
+    int font_offset = stbtt_GetFontOffsetForIndex(font.buffer.data(), font.index);
+    stbtt_fontinfo font_info;
+    if (stbtt_InitFont(&font_info, font.buffer.data(), font_offset) == 0)
+        return Polygons();
+
+    int glyph_index = stbtt_FindGlyphIndex(&(font_info), letter);
+    int advanceWidth, leftSideBearing;
+    stbtt_GetGlyphHMetrics(&(font_info), glyph_index, &advanceWidth,
+                           &leftSideBearing);
+
+    stbtt_vertex *vertices;
+    int num_verts = stbtt_GetGlyphShape(&(font_info), glyph_index, &vertices);
+    if (num_verts < 0) return {}; // no shape
+
+    int *         contour_lengths = NULL;
+    int           num_countour    = 0;
+    stbtt__point *points = stbtt_FlattenCurves(vertices, num_verts, font.flatness,
+                                               &contour_lengths,
+                                               &num_countour,
+                                               (font_info).userdata);
+
+    Polygons result;
+    result.reserve(num_countour);
+    size_t pi = 0; // point index
+    for (size_t ci = 0; ci < num_countour; ++ci) {
+        int    length = contour_lengths[ci];
+        Points pts;
+        pts.reserve(length);
+        for (size_t i = 0; i < length; i++) {
+            const stbtt__point &point = points[pi];
+            pi++;
+            pts.emplace_back(point.x, point.y);
+        }
+        result.emplace_back(pts);
+    }
+
+    BoundingBox bb;
+    for (auto &r : result) bb.merge(r.points);
+
+    // inner ccw
+    // outer cw
+    return result;
+}
+
+indexed_triangle_set Emboss::create_model(const std::string &text,
+                                          const Font &       font,
+                                          float              z_size)
+{
+    return indexed_triangle_set();
+}