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/*
* Copyright (c) 2020, Srimanta Barua <srimanta.barua1@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/Span.h>
#include <AK/Vector.h>
#include <LibGfx/AffineTransform.h>
#include <LibGfx/Bitmap.h>
#include <LibTTF/Tables.h>
#include <math.h>
namespace TTF {
class Rasterizer {
public:
Rasterizer(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;
};
class Loca {
public:
static Optional<Loca> from_slice(const ReadonlyBytes&, u32 num_glyphs, IndexToLocFormat);
u32 get_glyph_offset(u32 glyph_id) const;
private:
Loca(const ReadonlyBytes& slice, u32 num_glyphs, IndexToLocFormat index_to_loc_format)
: m_slice(slice)
, m_num_glyphs(num_glyphs)
, m_index_to_loc_format(index_to_loc_format)
{
}
ReadonlyBytes m_slice;
u32 m_num_glyphs { 0 };
IndexToLocFormat m_index_to_loc_format;
};
class Glyf {
public:
class Glyph {
public:
Glyph(const ReadonlyBytes& slice, i16 xmin, i16 ymin, i16 xmax, i16 ymax, i16 num_contours = -1)
: m_xmin(xmin)
, m_ymin(ymin)
, m_xmax(xmax)
, m_ymax(ymax)
, m_num_contours(num_contours)
, m_slice(slice)
{
if (m_num_contours >= 0) {
m_type = Type::Simple;
}
}
template<typename GlyphCb>
RefPtr<Gfx::Bitmap> raster(float x_scale, float y_scale, GlyphCb glyph_callback) const
{
switch (m_type) {
case Type::Simple:
return raster_simple(x_scale, y_scale);
case Type::Composite:
return raster_composite(x_scale, y_scale, glyph_callback);
}
VERIFY_NOT_REACHED();
}
int ascender() const { return m_ymax; }
int descender() const { return m_ymin; }
private:
enum class Type {
Simple,
Composite,
};
class ComponentIterator {
public:
struct Item {
u16 glyph_id;
Gfx::AffineTransform affine;
};
ComponentIterator(const ReadonlyBytes& slice)
: m_slice(slice)
{
}
Optional<Item> next();
private:
ReadonlyBytes m_slice;
bool m_has_more { true };
u32 m_offset { 0 };
};
void raster_inner(Rasterizer&, Gfx::AffineTransform&) const;
RefPtr<Gfx::Bitmap> raster_simple(float x_scale, float y_scale) const;
template<typename GlyphCb>
RefPtr<Gfx::Bitmap> raster_composite(float x_scale, float y_scale, GlyphCb glyph_callback) const
{
u32 width = (u32)(ceil((m_xmax - m_xmin) * x_scale)) + 1;
u32 height = (u32)(ceil((m_ymax - m_ymin) * y_scale)) + 1;
Rasterizer rasterizer(Gfx::IntSize(width, height));
auto affine = Gfx::AffineTransform().scale(x_scale, -y_scale).translate(-m_xmin, -m_ymax);
ComponentIterator component_iterator(m_slice);
while (true) {
auto opt_item = component_iterator.next();
if (!opt_item.has_value()) {
break;
}
auto item = opt_item.value();
auto affine_here = affine.multiply(item.affine);
auto glyph = glyph_callback(item.glyph_id);
glyph.raster_inner(rasterizer, affine_here);
}
return rasterizer.accumulate();
}
Type m_type { Type::Composite };
i16 m_xmin { 0 };
i16 m_ymin { 0 };
i16 m_xmax { 0 };
i16 m_ymax { 0 };
i16 m_num_contours { -1 };
ReadonlyBytes m_slice;
};
Glyf(const ReadonlyBytes& slice)
: m_slice(slice)
{
}
Glyph glyph(u32 offset) const;
private:
enum class Offsets {
XMin = 2,
YMin = 4,
XMax = 6,
YMax = 8,
};
enum class Sizes {
GlyphHeader = 10,
};
ReadonlyBytes m_slice;
};
}
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