LibGfx: Use AntiAliasingPainter::fill_path() for drawing font glyphs

Using the general AA painter fill_path() is indistinguishable from the
previous rasterizer, so this switch simply allows us to share more code.

Userland/Libraries/LibGfx/CMakeLists.txt

@@ -21,7 +21,6 @@ set(SOURCES
     Font/OpenType/Font.cpp
     Font/OpenType/Glyf.cpp
     Font/OpenType/Hinting/Opcodes.cpp
-    Font/PathRasterizer.cpp
     Font/ScaledFont.cpp
     Font/Typeface.cpp
     Font/WOFF/Font.cpp

Userland/Libraries/LibGfx/Font/OpenType/Glyf.cpp

@@ -4,7 +4,9 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
+#include <LibGfx/AntiAliasingPainter.h>
 #include <LibGfx/Font/OpenType/Glyf.h>
+#include <LibGfx/Painter.h>
 #include <LibGfx/Path.h>
 #include <LibGfx/Point.h>
 
@@ -258,7 +260,7 @@ ReadonlyBytes Glyf::Glyph::program() const
     return m_slice.slice(instructions_start + 2, num_instructions);
 }
 
-void Glyf::Glyph::rasterize_impl(Gfx::PathRasterizer& rasterizer, Gfx::AffineTransform const& transform) const
+void Glyf::Glyph::rasterize_impl(Gfx::Painter& painter, Gfx::AffineTransform const& transform) const
 {
     // Get offset for flags, x, and y.
     u16 num_points = be_u16(m_slice.offset_pointer((m_num_contours - 1) * 2)) + 1;
@@ -332,20 +334,23 @@ void Glyf::Glyph::rasterize_impl(Gfx::PathRasterizer& rasterizer, Gfx::AffineTra
         }
     }
 
-    rasterizer.draw_path(path);
+    constexpr auto base_color = Color::White;
+    Gfx::AntiAliasingPainter aa_painter { painter };
+    aa_painter.fill_path(path, base_color);
 }
 
 RefPtr<Gfx::Bitmap> Glyf::Glyph::rasterize_simple(i16 font_ascender, i16 font_descender, float x_scale, float y_scale, Gfx::GlyphSubpixelOffset subpixel_offset) const
 {
     u32 width = (u32)(ceilf((m_xmax - m_xmin) * x_scale)) + 2;
     u32 height = (u32)(ceilf((font_ascender - font_descender) * y_scale)) + 2;
-    Gfx::PathRasterizer rasterizer(Gfx::IntSize(width, height));
+    auto bitmap = Gfx::Bitmap::create(Gfx::BitmapFormat::BGRA8888, { width, height }).release_value_but_fixme_should_propagate_errors();
     auto affine = Gfx::AffineTransform()
                       .translate(subpixel_offset.to_float_point())
                       .scale(x_scale, -y_scale)
                       .translate(-m_xmin, -font_ascender);
-    rasterize_impl(rasterizer, affine);
+    Gfx::Painter painter { bitmap };
-    return rasterizer.accumulate();
+    rasterize_impl(painter, affine);
+    return bitmap;
 }
 
 Optional<Glyf::Glyph> Glyf::glyph(u32 offset) const

Userland/Libraries/LibGfx/Font/OpenType/Glyf.h

@@ -13,7 +13,7 @@
 #include <LibGfx/Bitmap.h>
 #include <LibGfx/Font/Font.h>
 #include <LibGfx/Font/OpenType/Tables.h>
-#include <LibGfx/Font/PathRasterizer.h>
+#include <LibGfx/Painter.h>
 #include <math.h>
 
 namespace OpenType {
@@ -97,11 +97,11 @@ public:
             u32 m_offset { 0 };
         };
 
-        void rasterize_impl(Gfx::PathRasterizer&, Gfx::AffineTransform const&) const;
+        void rasterize_impl(Gfx::Painter&, Gfx::AffineTransform const&) const;
         RefPtr<Gfx::Bitmap> rasterize_simple(i16 ascender, i16 descender, float x_scale, float y_scale, Gfx::GlyphSubpixelOffset) const;
 
         template<typename GlyphCb>
-        void rasterize_composite_loop(Gfx::PathRasterizer& rasterizer, Gfx::AffineTransform const& transform, GlyphCb glyph_callback) const
+        void rasterize_composite_loop(Gfx::Painter& painter, Gfx::AffineTransform const& transform, GlyphCb glyph_callback) const
         {
             ComponentIterator component_iterator(m_slice);
 
@@ -118,9 +118,9 @@ public:
                     continue;
 
                 if (glyph->m_type == Type::Simple) {
-                    glyph->rasterize_impl(rasterizer, affine_here);
+                    glyph->rasterize_impl(painter, affine_here);
                 } else {
-                    glyph->rasterize_composite_loop(rasterizer, transform, glyph_callback);
+                    glyph->rasterize_composite_loop(painter, transform, glyph_callback);
                 }
             }
         }
@@ -130,15 +130,16 @@ public:
         {
             u32 width = (u32)(ceilf((m_xmax - m_xmin) * x_scale)) + 1;
             u32 height = (u32)(ceilf((font_ascender - font_descender) * y_scale)) + 1;
-            Gfx::PathRasterizer rasterizer(Gfx::IntSize(width, height));
+            auto bitmap = Gfx::Bitmap::create(Gfx::BitmapFormat::BGRA8888, { width, height }).release_value_but_fixme_should_propagate_errors();
             auto affine = Gfx::AffineTransform()
                               .translate(subpixel_offset.to_float_point())
                               .scale(x_scale, -y_scale)
                               .translate(-m_xmin, -font_ascender);
 
-            rasterize_composite_loop(rasterizer, affine, glyph_callback);
+            Gfx::Painter painter { bitmap };
+            rasterize_composite_loop(painter, affine, glyph_callback);
 
-            return rasterizer.accumulate();
+            return bitmap;
         }
 
         Type m_type { Type::Composite };

Userland/Libraries/LibGfx/Font/PathRasterizer.cpp

@@ -1,124 +0,0 @@
-/*
- * Copyright (c) 2020, Srimanta Barua <srimanta.barua1@gmail.com>
- * Copyright (c) 2023, Jelle Raaijmakers <jelle@gmta.nl>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#include <LibGfx/Font/PathRasterizer.h>
-
-namespace Gfx {
-
-PathRasterizer::PathRasterizer(Gfx::IntSize size)
-    : m_size(size)
-{
-    m_data.resize(m_size.area());
-    for (int i = 0; i < m_size.area(); i++)
-        m_data[i] = 0.f;
-}
-
-void PathRasterizer::draw_path(Gfx::Path& path)
-{
-    for (auto& line : path.split_lines())
-        draw_line(line.a(), line.b());
-}
-
-RefPtr<Gfx::Bitmap> PathRasterizer::accumulate()
-{
-    auto bitmap_or_error = Gfx::Bitmap::create(Gfx::BitmapFormat::BGRA8888, m_size);
-    if (bitmap_or_error.is_error())
-        return {};
-    auto bitmap = bitmap_or_error.release_value_but_fixme_should_propagate_errors();
-    Color base_color = Color::from_rgb(0xffffff);
-    for (int y = 0; y < m_size.height(); y++) {
-        float accumulator = 0.f;
-        for (int x = 0; x < m_size.width(); x++) {
-            accumulator += m_data[y * m_size.width() + x];
-            float value = AK::min(AK::abs(accumulator), 1.f);
-            u8 alpha = value * 255.f;
-            bitmap->set_pixel(x, y, base_color.with_alpha(alpha));
-        }
-    }
-    return bitmap;
-}
-
-void PathRasterizer::draw_line(Gfx::FloatPoint p0, Gfx::FloatPoint p1)
-{
-    // FIXME: Shift x and y according to dy/dx
-    if (p0.x() < 0.f)
-        p0.set_x(roundf(p0.x()));
-    if (p0.y() < 0.f)
-        p0.set_y(roundf(p0.y()));
-    if (p1.x() < 0.f)
-        p1.set_x(roundf(p1.x()));
-    if (p1.y() < 0.f)
-        p1.set_y(roundf(p1.y()));
-
-    if (p0.x() < 0.f || p0.y() < 0.f || p0.x() > m_size.width() || p0.y() > m_size.height()) {
-        dbgln("!P0({},{})", p0.x(), p0.y());
-        return;
-    }
-
-    if (p1.x() < 0.f || p1.y() < 0.f || p1.x() > m_size.width() || p1.y() > m_size.height()) {
-        dbgln("!P1({},{})", p1.x(), p1.y());
-        return;
-    }
-
-    // If we're on the same Y, there's no need to draw
-    if (p0.y() == p1.y())
-        return;
-
-    float direction = -1.f;
-    if (p1.y() < p0.y()) {
-        direction = 1.f;
-        AK::swap(p0, p1);
-    }
-
-    float const dxdy = (p1.x() - p0.x()) / (p1.y() - p0.y());
-    float const dydx = AK::abs(1.f / dxdy);
-
-    u32 y0 = floorf(p0.y());
-    u32 y1 = ceilf(p1.y());
-    float x_cur = p0.x();
-
-    for (u32 y = y0; y < y1; y++) {
-        u32 line_offset = m_size.width() * y;
-
-        float dy = AK::min(y + 1.f, p1.y()) - AK::max(static_cast<float>(y), p0.y());
-        float directed_dy = dy * direction;
-        float x_next = x_cur + dy * dxdy;
-        x_next = AK::max(x_next, 0.f);
-        float x0 = x_cur;
-        float x1 = x_next;
-        if (x1 < x0) {
-            x1 = x_cur;
-            x0 = x_next;
-        }
-        float x0_floor = floorf(x0);
-        float x1_ceil = ceilf(x1);
-        u32 x0_floor_i = x0_floor;
-
-        if (x1_ceil <= x0_floor + 1.f) {
-            // If x0 and x1 are within the same pixel, then area to the right is (1 - (mid(x0, x1) - x0_floor)) * dy
-            float area = .5f * (x0 + x1) - x0_floor;
-            m_data[line_offset + x0_floor_i] += directed_dy * (1.f - area);
-            if (x0_floor_i + 1 < static_cast<u32>(m_size.width()))
-                m_data[line_offset + x0_floor_i + 1] += directed_dy * area;
-        } else {
-            float x0_right = 1.f - (x0 - x0_floor);
-            u32 x1_floor_i = floorf(x1);
-            float area_upto_here = .5f * x0_right * x0_right * dydx;
-            m_data[line_offset + x0_floor_i] += direction * area_upto_here;
-            for (u32 x = x0_floor_i + 1; x < x1_floor_i; x++) {
-                m_data[line_offset + x] += direction * dydx;
-                area_upto_here += dydx;
-            }
-            float remaining_area = dy - area_upto_here;
-            m_data[line_offset + x1_floor_i] += direction * remaining_area;
-        }
-
-        x_cur = x_next;
-    }
-}
-
-}

Userland/Libraries/LibGfx/Font/PathRasterizer.h

@@ -1,28 +0,0 @@
-/*
- * Copyright (c) 2020, Srimanta Barua <srimanta.barua1@gmail.com>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <AK/Vector.h>
-#include <LibGfx/Bitmap.h>
-#include <LibGfx/Path.h>
-
-namespace Gfx {
-
-class PathRasterizer {
-public:
-    PathRasterizer(Gfx::IntSize);
-    void draw_path(Gfx::Path&);
-    RefPtr<Gfx::Bitmap> accumulate();
-
-private:
-    void draw_line(Gfx::FloatPoint, Gfx::FloatPoint);
-
-    Gfx::IntSize m_size;
-    Vector<float> m_data;
-};
-
-}

Userland/Libraries/LibPDF/Fonts/PS1FontProgram.cpp

@@ -4,7 +4,6 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <LibGfx/Font/PathRasterizer.h>
 #include <LibPDF/CommonNames.h>
 #include <LibPDF/Encoding.h>
 #include <LibPDF/Fonts/PS1FontProgram.h>

Userland/Libraries/LibPDF/Fonts/Type1FontProgram.cpp

@@ -4,7 +4,8 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <LibGfx/Font/PathRasterizer.h>
+#include <LibGfx/AntiAliasingPainter.h>
+#include <LibGfx/Painter.h>
 #include <LibPDF/Fonts/Type1FontProgram.h>
 
 namespace PDF {
@@ -54,15 +55,19 @@ enum ExtendedCommand {
 
 RefPtr<Gfx::Bitmap> Type1FontProgram::rasterize_glyph(DeprecatedFlyString const& char_name, float width, Gfx::GlyphSubpixelOffset subpixel_offset)
 {
+    constexpr auto base_color = Color::White;
     auto path = build_char(char_name, width, subpixel_offset);
     auto bounding_box = path.bounding_box().size();
 
     u32 w = (u32)ceilf(bounding_box.width()) + 2;
     u32 h = (u32)ceilf(bounding_box.height()) + 2;
 
-    Gfx::PathRasterizer rasterizer(Gfx::IntSize(w, h));
+    auto bitmap = Gfx::Bitmap::create(Gfx::BitmapFormat::BGRA8888, { w, h }).release_value_but_fixme_should_propagate_errors();
-    rasterizer.draw_path(path);
+    Gfx::Painter painter { bitmap };
-    return rasterizer.accumulate();
+    Gfx::AntiAliasingPainter aa_painter { painter };
+
+    aa_painter.fill_path(path, base_color);
+    return bitmap;
 }
 
 Gfx::Path Type1FontProgram::build_char(DeprecatedFlyString const& char_name, float width, Gfx::GlyphSubpixelOffset subpixel_offset)