Add boldness and skew(italic) for embossed text

Change line_gap and char_gap to optional value

src/libslic3r/Emboss.cpp

@@ -9,6 +9,9 @@
 
 #include <Triangulation.hpp> // CGAL project
 #include "libslic3r.h"
+
+#include "ClipperUtils.hpp" // for boldness - polygon extend(offset)
+
 using namespace Slic3r;
 
 double Emboss::SHAPE_SCALE = 0.001;//SCALING_FACTOR;
@@ -541,8 +544,11 @@ ExPolygons Emboss::text2shapes(Font &          font,
     std::wstring ws = boost::nowide::widen(text);
     for (wchar_t wc: ws){
         if (wc == '\n') { 
+            int line_height = font.ascent - font.descent + font.linegap;
+            if (font_prop.line_gap.has_value())
+                line_height += *font_prop.line_gap;
             cursor.x() = 0;
-            cursor.y() -= (font.ascent - font.descent + font.linegap + font_prop.line_gap) / SHAPE_SCALE;
+            cursor.y() -= static_cast<int>(line_height / SHAPE_SCALE);
             continue;
         } 
         if (wc == '\t') {
@@ -550,7 +556,10 @@ ExPolygons Emboss::text2shapes(Font &          font,
             const int count_spaces = 4;
             std::optional<Glyph> space_opt = Private::get_glyph(int(' '), font, font_prop, font.cache, font_info_opt);
             if (!space_opt.has_value()) continue;
-            cursor.x() += (count_spaces *(space_opt->advance_width + font_prop.char_gap)) / SHAPE_SCALE;
+            int width = space_opt->advance_width;
+            if (font_prop.char_gap.has_value()) 
+                width += *font_prop.char_gap;
+            cursor.x() += static_cast<int>((count_spaces * width) / SHAPE_SCALE);
             continue;
         }
 
@@ -562,7 +571,30 @@ ExPolygons Emboss::text2shapes(Font &          font,
         ExPolygons expolygons = glyph_opt->shape; // copy
         for (ExPolygon &expolygon : expolygons) 
             expolygon.translate(cursor);
-        cursor.x() += (glyph_opt->advance_width + font_prop.char_gap) / SHAPE_SCALE;
+
+        if (font_prop.boldness.has_value()) {
+            float delta = *font_prop.boldness / SHAPE_SCALE;
+            expolygons  = offset_ex(expolygons, delta);
+        }
+
+        if (font_prop.skew.has_value()) {
+            const float& ratio = *font_prop.skew;
+            auto skew = [&ratio](Polygon &polygon) { 
+                for (Point &p : polygon.points) { 
+                    p.x() += p.y() * ratio;
+                }
+            };
+            for (ExPolygon &expolygon : expolygons) { 
+                skew(expolygon.contour);
+                for (Polygon &hole : expolygon.holes)
+                    skew(hole);
+            }
+        }
+
+        int width = glyph_opt->advance_width;
+        if (font_prop.char_gap.has_value()) 
+            width += *font_prop.char_gap;
+        cursor.x() += static_cast<int>(width / SHAPE_SCALE);
         expolygons_append(result, expolygons);
     }
     result = Slic3r::union_ex(result);

src/libslic3r/Format/3mf.cpp

@@ -156,6 +156,8 @@ static constexpr const char *CHAR_GAP_ATTR    = "char_gap";
 static constexpr const char *LINE_GAP_ATTR    = "line_gap";
 static constexpr const char *LINE_HEIGHT_ATTR = "line_height";
 static constexpr const char *DEPTH_ATTR       = "depth";
+static constexpr const char *BOLDNESS_ATTR    = "boldness";
+static constexpr const char *SKEW_ATTR        = "skew";
 
 static constexpr const char *FONT_FAMILY_ATTR    = "family";
 static constexpr const char *FONT_FACE_NAME_ATTR = "face_name";
@@ -3254,10 +3256,18 @@ void TextConfigurationSerialization::to_xml(std::stringstream &stream, const Tex
 
     // font property
     const FontProp &fp = tc.font_prop;
-    stream << CHAR_GAP_ATTR << "=\"" << fp.char_gap << "\" ";
-    stream << LINE_GAP_ATTR << "=\"" << fp.line_gap << "\" ";
+    if (fp.char_gap.has_value())
+        stream << CHAR_GAP_ATTR << "=\"" << *fp.char_gap << "\" ";
+    if (fp.line_gap.has_value())
+        stream << LINE_GAP_ATTR << "=\"" << *fp.line_gap << "\" ";
+
     stream << LINE_HEIGHT_ATTR << "=\"" << fp.size_in_mm << "\" ";
     stream << DEPTH_ATTR << "=\"" << fp.emboss << "\" ";
+    if (fp.boldness.has_value())
+        stream << BOLDNESS_ATTR << "=\"" << *fp.boldness << "\" ";
+    if (fp.skew.has_value())
+        stream << SKEW_ATTR << "=\"" << *fp.skew << "\" ";
+
     // font descriptor
     if (fp.family.has_value())
         stream << FONT_FAMILY_ATTR << "=\"" << *fp.family << "\" ";
@@ -3280,8 +3290,17 @@ std::optional<TextConfiguration> TextConfigurationSerialization::read(const char
     FontItem fi(font_name, font_descriptor, type);
 
     FontProp fp;
-    fp.char_gap = get_attribute_value_int(attributes, num_attributes, CHAR_GAP_ATTR);
-    fp.line_gap = get_attribute_value_int(attributes, num_attributes, LINE_GAP_ATTR);
+    int char_gap = get_attribute_value_int(attributes, num_attributes, CHAR_GAP_ATTR);
+    if (char_gap != 0) fp.char_gap = char_gap;
+    int line_gap = get_attribute_value_int(attributes, num_attributes, LINE_GAP_ATTR); 
+    if (line_gap != 0) fp.line_gap = line_gap;
+    float boldness = get_attribute_value_float(attributes, num_attributes, BOLDNESS_ATTR);
+    if (std::fabs(boldness) > std::numeric_limits<float>::epsilon())
+        fp.boldness = boldness;
+    float skew = get_attribute_value_float(attributes, num_attributes, SKEW_ATTR);
+    if (std::fabs(skew) > std::numeric_limits<float>::epsilon())
+        fp.skew = skew;
+
     fp.size_in_mm = get_attribute_value_float(attributes, num_attributes, LINE_HEIGHT_ATTR);
     fp.emboss = get_attribute_value_float(attributes, num_attributes, DEPTH_ATTR);
 

src/libslic3r/TextConfiguration.hpp

@@ -38,11 +38,20 @@ using FontList = std::vector<FontItem>;
 struct FontProp
 {
     // define extra space between letters, negative mean closer letter
-    int char_gap = 0;
+    std::optional<int> char_gap = 0;
     // define extra space between lines, negative mean closer lines
-    int line_gap = 0;
+    std::optional<int> line_gap = 0;
     // Z depth of text [in mm]
     float emboss = 5;
+
+    // positive value mean wider character shape
+    // negative value mean tiner character shape
+    std::optional<float> boldness = 0.f; // [in mm]
+
+    // positive value mean italic of character (CW)
+    // negative value mean CCW skew (unItalic)
+    std::optional<float> skew = 0.f;
+
     // TODO: add enum class Align: center/left/right
     
     //////

src/slic3r/GUI/Gizmos/GLGizmoEmboss.cpp

@@ -423,7 +423,7 @@ void GLGizmoEmboss::initialize()
         m_gui_cfg->text_size.y +
         style.WindowPadding.y * 2.f;
     m_gui_cfg->minimal_window_size = ImVec2(window_width, window_height);
-    float advance_height = (input_height + style.ItemSpacing.y) * 4.f;
+    float advance_height = (input_height + style.ItemSpacing.y) * 6.f;
     m_gui_cfg->minimal_window_size_with_advance =
         ImVec2(window_width, window_height + advance_height);
 
@@ -765,13 +765,21 @@ void GLGizmoEmboss::draw_advanced()
     ImGui::SetNextItemWidth(m_gui_cfg->advanced_input_width);
     if (ImGui::InputFloat(_u8L("Emboss[in mm]").c_str(), &m_font_prop.emboss))
         process();
-    ImGui::SetNextItemWidth(2*m_gui_cfg->advanced_input_width);
-    if (ImGui::InputInt(_u8L("CharGap[in font points]").c_str(),
-                        &m_font_prop.char_gap))
+    
+    ImGui::SetNextItemWidth(2 * m_gui_cfg->advanced_input_width);
+    if(ImGuiWrapper::input_optional_int(_u8L("CharGap[in font points]").c_str(), m_font_prop.char_gap))
         process();
+
     ImGui::SetNextItemWidth(2*m_gui_cfg->advanced_input_width);
-    if (ImGui::InputInt(_u8L("LineGap[in font points]").c_str(),
-                        &m_font_prop.line_gap))
+    if (ImGuiWrapper::input_optional_int(_u8L("LineGap[in font points]").c_str(), m_font_prop.line_gap))
+        process();
+
+    ImGui::SetNextItemWidth(2 * m_gui_cfg->advanced_input_width);
+    if (m_imgui->slider_optional_float(_u8L("Boldness[in font points]").c_str(), m_font_prop.boldness, -200.f, 200.f, "%.0f", 1.f, false, _L("tiny / wide chars")))
+        process();
+
+    ImGui::SetNextItemWidth(2 * m_gui_cfg->advanced_input_width);
+    if (m_imgui->slider_optional_float(_u8L("Skew ratio").c_str(), m_font_prop.skew, -1.f, 1.f, "%.2f", 1.f, false, _L("italic strength")))
         process();
 
     // when more collection add selector
@@ -793,6 +801,7 @@ void GLGizmoEmboss::draw_advanced()
         }
     }
 
+
 #ifdef ALLOW_DEBUG_MODE
     std::string descriptor = m_font_list[m_font_selected].path;
     ImGui::Text("family = %s", (m_font_prop.family.has_value() ?

src/slic3r/GUI/ImGuiWrapper.cpp

@@ -1041,6 +1041,93 @@ bool ImGuiWrapper::want_any_input() const
     return io.WantCaptureMouse || io.WantCaptureKeyboard || io.WantTextInput;
 }
 
+template <typename T, typename Func> 
+static bool input_optional(std::optional<T> &v, Func& f, std::function<bool(const T&)> is_default)
+{
+    if (v.has_value()) {
+        if (f(*v)) {
+            if (is_default(*v)) v.reset();
+            return true;
+        }
+    } else {
+        T val = 0;
+        if (f(val)) {
+            if (!is_default(val)) v = val;
+            return true;
+        }
+    }
+    return false;
+}
+
+bool ImGuiWrapper::input_optional_int(const char *        label,
+                                      std::optional<int>& v,
+                                      int                 step,
+                                      int                 step_fast,
+                                      ImGuiInputTextFlags flags)
+{
+    auto func = [&](int &value) {
+        return ImGui::InputInt(label, &value, step, step_fast, flags);
+    };
+    std::function<bool(const int &)> is_default = 
+        [](const int &value) -> bool { return value == 0; };
+    return input_optional(v, func, is_default);
+}
+
+bool ImGuiWrapper::input_optional_float(const char *          label,
+                                        std::optional<float> &v,
+                                        float                 step,
+                                        float                 step_fast,
+                                        const char *          format,
+                                        ImGuiInputTextFlags   flags)
+{
+    auto func = [&](float &value) {
+        return ImGui::InputFloat(label, &value, step, step_fast, format, flags);
+    };
+    std::function<bool(const float &)> is_default =
+        [](const float &value) -> bool {
+        return std::fabs(value) < std::numeric_limits<float>::epsilon();
+    };
+    return input_optional(v, func, is_default);
+}
+
+bool ImGuiWrapper::drag_optional_float(const char *          label,
+                                       std::optional<float> &v,
+                                       float                 v_speed,
+                                       float                 v_min,
+                                       float                 v_max,
+                                       const char *          format,
+                                       float                 power)
+{
+    auto func = [&](float &value) {
+        return ImGui::DragFloat(label, &value, v_speed, v_min, v_max, format, power);
+    };
+    std::function<bool(const float &)> is_default =
+        [](const float &value) -> bool {
+        return std::fabs(value) < std::numeric_limits<float>::epsilon();
+    };
+    return input_optional(v, func, is_default);
+}
+
+bool ImGuiWrapper::slider_optional_float(const char *          label,
+                                         std::optional<float> &v,
+                                         float                 v_min,
+                                         float                 v_max,
+                                         const char *          format,
+                                         float                 power,
+                                         bool                  clamp,
+                                         const wxString &      tooltip,
+                                         bool                  show_edit_btn)
+{
+    auto func = [&](float &value) {
+        return slider_float(label, &value, v_min, v_max, format, power, clamp, tooltip, show_edit_btn);
+    };
+    std::function<bool(const float &)> is_default =
+        [](const float &value) -> bool {
+        return std::fabs(value) < std::numeric_limits<float>::epsilon();
+    };
+    return input_optional(v, func, is_default);
+}
+
 std::string ImGuiWrapper::trunc(const std::string &text,
                                 float              width,
                                 const char *       tail)

src/slic3r/GUI/ImGuiWrapper.hpp

@@ -128,6 +128,12 @@ public:
     bool want_text_input() const;
     bool want_any_input() const;
 
+    // Input [optional] int for nonzero value more info in ImGui::InputInt
+    static bool input_optional_int(const char *label, std::optional<int>& v, int step=1, int step_fast=100, ImGuiInputTextFlags flags=0);
+    // Input [optional] float for nonzero value more info in ImGui::InputFloat
+    static bool input_optional_float(const char* label, std::optional<float> &v, float step = 0.0f, float step_fast = 0.0f, const char* format = "%.3f", ImGuiInputTextFlags flags = 0);
+    static bool drag_optional_float(const char* label, std::optional<float> &v, float v_speed, float v_min, float v_max, const char* format, float power);
+    bool slider_optional_float(const char* label, std::optional<float> &v, float v_min, float v_max, const char* format = "%.3f", float power = 1.0f, bool clamp = true, const wxString& tooltip = {}, bool show_edit_btn = true);
     /// <summary>
     /// Truncate text by ImGui draw function to specific width
     /// NOTE 1: ImGui must be initialized