Exploring raycasters and possibly make a little "doom like" game based on it.
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raycaster/amt/pixel.hpp

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24 KiB

#ifndef AMT_PIXEL_HPP
#define AMT_PIXEL_HPP
#include "matrix.hpp"
#include <algorithm>
#include <cmath>
#include <cstddef>
#include <cstdint>
#include <limits>
#include <string>
#include <stdexcept>
#include <type_traits>
namespace amt {
enum class PixelFormat {
rgba,
abgr,
rgb ,
bgr ,
ga , // gray scale and alpha
ag , // alpha and gray scale
g // gray scale
};
inline static constexpr auto get_pixel_format_from_channel(std::size_t c, bool little_endian = false) -> PixelFormat {
switch (c) {
case 1: return PixelFormat::g;
case 2: return little_endian ? PixelFormat::ag : PixelFormat::ga;
case 3: return little_endian ? PixelFormat::bgr : PixelFormat::rgb;
case 4: return little_endian ? PixelFormat::abgr : PixelFormat::abgr;
}
throw std::runtime_error(std::string("get_pixel_format_from_channel: unknown channel ") + std::to_string(c));
}
namespace detail {
static constexpr auto compare_float(float l, float r) noexcept -> bool {
return std::abs(l - r) < std::numeric_limits<float>::epsilon();
}
} // namespace detail
enum class BlendMode {
normal,
multiply,
screen,
overlay,
darken,
lighten,
colorDodge,
colorBurn,
hardLight,
softLight,
difference,
exclusion
};
struct RGBA {
using pixel_t = std::uint8_t;
using pixels_t = std::uint32_t;
constexpr RGBA() noexcept = default;
constexpr RGBA(RGBA const&) noexcept = default;
constexpr RGBA(RGBA &&) noexcept = default;
constexpr RGBA& operator=(RGBA const&) noexcept = default;
constexpr RGBA& operator=(RGBA &&) noexcept = default;
constexpr ~RGBA() noexcept = default;
// NOTE: Accepts RRGGBBAA
explicit constexpr RGBA(pixels_t color) noexcept
: RGBA((color >> (8 * 3)) & 0xff, (color >> (8 * 2)) & 0xff, (color >> (8 * 1)) & 0xff, (color >> (8 * 0)) & 0xff)
{}
constexpr RGBA(pixel_t r, pixel_t g, pixel_t b, pixel_t a = 0xff) noexcept
: m_data {r, g, b, a}
{}
constexpr RGBA(pixel_t color, pixel_t a = 0xff) noexcept
: RGBA(color, color, color, a)
{}
// NOTE: Returns RRGGBBAA
constexpr auto to_hex() const noexcept -> pixels_t {
auto r = static_cast<pixels_t>(this->r());
auto b = static_cast<pixels_t>(this->b());
auto g = static_cast<pixels_t>(this->g());
auto a = static_cast<pixels_t>(this->a());
return (r << (8 * 3)) | (g << (8 * 2)) | (b << (8 * 1)) | (a << (8 * 0));
}
constexpr auto r() const noexcept -> pixel_t { return m_data[0]; }
constexpr auto g() const noexcept -> pixel_t { return m_data[1]; }
constexpr auto b() const noexcept -> pixel_t { return m_data[2]; }
constexpr auto a() const noexcept -> pixel_t { return m_data[3]; }
constexpr auto r() noexcept -> pixel_t& { return m_data[0]; }
constexpr auto g() noexcept -> pixel_t& { return m_data[1]; }
constexpr auto b() noexcept -> pixel_t& { return m_data[2]; }
constexpr auto a() noexcept -> pixel_t& { return m_data[3]; }
/**
* @returns the value is between 0 and 1
*/
constexpr auto brightness() const noexcept -> float {
// 0.299*R + 0.587*G + 0.114*B
auto tr = normalize(r());
auto tg = normalize(g());
auto tb = normalize(b());
return (0.299 * tr + 0.587 * tg + 0.114 * tb);
}
template <typename T>
requires std::is_arithmetic_v<T>
constexpr auto operator/(T val) const noexcept {
auto d = static_cast<float>(val);
return RGBA(
static_cast<pixel_t>(r() / d),
static_cast<pixel_t>(g() / d),
static_cast<pixel_t>(b() / d),
a()
);
}
template <typename T>
requires std::is_arithmetic_v<T>
constexpr auto operator*(T val) const noexcept {
auto d = static_cast<float>(val);
return RGBA(
static_cast<pixel_t>(r() * d),
static_cast<pixel_t>(g() * d),
static_cast<pixel_t>(b() * d),
a()
);
}
private:
static constexpr auto normalize(pixel_t p) noexcept -> float {
return float(p) / 255;
}
static constexpr auto to_pixel(float p) noexcept -> pixel_t {
return static_cast<pixel_t>(p * 255);
}
template <BlendMode M>
static constexpr auto blend_helper() noexcept {
constexpr auto mix_helper = [](float s, float b, float a) -> float {
// (1 - αb) x Cs + αb x B(Cb, Cs)
return (1 - a) * s + a * b;
};
if constexpr (M == BlendMode::normal) {
return [mix_helper](float bg, float fg, float alpha) { return mix_helper(bg, fg, alpha); };
} else if constexpr (M == BlendMode::multiply) {
return [mix_helper](float bg, float fg, float alpha) { return mix_helper(bg, bg * fg, alpha); };
} else if constexpr (M == BlendMode::screen) {
return [mix_helper](float bg, float fg, float alpha) {
// Cb + Cs -(Cb x Cs)
auto bf = bg + fg - (bg * fg);
return mix_helper(bg, bf, alpha);
};
} else if constexpr (M == BlendMode::overlay) {
return [mix_helper](float bg, float fg, float alpha, auto&& hard_light_fn, auto&& multiply_fn, auto&& screen_fn) {
// HardLight(Cs, Cb)
auto hl = hard_light_fn(bg, fg, alpha, multiply_fn, screen_fn);
return mix_helper(bg, hl, alpha);
};
} else if constexpr (M == BlendMode::darken) {
return [mix_helper](float bg, float fg, float alpha) {
return mix_helper(bg, std::min(bg, fg), alpha);
};
} else if constexpr (M == BlendMode::lighten) {
return [mix_helper](float bg, float fg, float alpha) {
return mix_helper(bg, std::max(bg, fg), alpha);
};
} else if constexpr (M == BlendMode::colorDodge) {
return [mix_helper](float bg, float fg, float alpha) {
constexpr auto fn = [](float b, float s) -> float {
if (b == 0) return 0;
if (s == 255) return 255;
return std::min(1.f, b / (1.f - s));
};
auto bf = fn(bg, fg);
return mix_helper(bg, bf, alpha);
};
} else if constexpr (M == BlendMode::colorBurn) {
return [mix_helper](float bg, float fg, float alpha) {
constexpr auto fn = [](float b, float s) -> float {
if (b == 255) return 255;
if (s == 0) return 0;
return 1.f - std::min(1.f, (1.f - b) / s);
};
auto bf = fn(bg, fg);
return mix_helper(bg, bf, alpha);
};
} else if constexpr (M == BlendMode::hardLight) {
return [mix_helper](float bg, float fg, float alpha, auto&& multiply_fn, auto&& screen_fn) {
auto fn = [&multiply_fn, &screen_fn](float b, float s, float a) -> float {
if (s <= 0.5f) {
return multiply_fn(b, 2.f * s, a);
} else {
return screen_fn(b, 2.f * s - 1.f, a);
}
};
auto bf = fn(bg, fg, alpha);
return mix_helper(bg, bf, alpha);
};
} else if constexpr (M == BlendMode::softLight) {
return [mix_helper](float bg, float fg, float alpha) {
constexpr auto fn = [](float b, float s) -> float {
if (s <= 0.5f) {
// B(Cb, Cs) = Cb - (1 - 2 x Cs) x Cb x (1 - Cb)
return b - (1.f - 2.f * s) * b * (1 - b);
} else {
float d{};
if (b <= 0.5f) {
// D(Cb) = ((16 * Cb - 12) x Cb + 4) x Cb
d = ((16 * b - 12) * b + 4) * b;
} else {
// D(Cb) = sqrt(Cb)
d = std::sqrt(b);
}
// B(Cb, Cs) = Cb + (2 x Cs - 1) x (D(Cb) - Cb)
return b + (2 * s - 1) * (d - b);
}
};
auto bf = fn(bg, fg);
return mix_helper(bg, bf, alpha);
};
} else if constexpr (M == BlendMode::difference) {
return [mix_helper](float bg, float fg, float alpha) {
// B(Cb, Cs) = | Cb - Cs |
return mix_helper(bg, (bg > fg ? (bg - fg) : (fg - bg)), alpha);
};
} else if constexpr (M == BlendMode::exclusion) {
return [mix_helper](float bg, float fg, float alpha) {
constexpr auto fn = [](float b, float s) -> float {
// B(Cb, Cs) = Cb + Cs - 2 x Cb x Cs
return b + s - 2 * b * s;
};
auto bf = fn(bg, fg);
return mix_helper(bg, bf, alpha);
};
}
};
public:
template <BlendMode M>
constexpr auto blend(RGBA color) const noexcept -> RGBA {
auto ab = normalize(a());
auto as = normalize(color.a());
// αs x 1 + αb x (1 – αs)
auto alpha = to_pixel(as + ab * (1 - as));
auto lr = normalize(r());
auto lg = normalize(g());
auto lb = normalize(b());
auto rr = normalize(color.r());
auto rg = normalize(color.g());
auto rb = normalize(color.b());
auto nr = 0.f;
auto ng = 0.f;
auto nb = 0.f;
if constexpr (M == BlendMode::normal) {
auto fn = blend_helper<BlendMode::normal>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
} else if constexpr (M == BlendMode::multiply) {
auto fn = blend_helper<BlendMode::multiply>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
} else if constexpr (M == BlendMode::screen) {
auto fn = blend_helper<BlendMode::screen>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
} else if constexpr (M == BlendMode::overlay) {
auto fn = blend_helper<BlendMode::overlay>();
auto hard_light_fn = blend_helper<BlendMode::hardLight>();
auto multiply_fn = blend_helper<BlendMode::multiply>();
auto screen_fn = blend_helper<BlendMode::screen>();
nr = fn(lr, rr, ab, hard_light_fn, multiply_fn, screen_fn);
ng = fn(lg, rg, ab, hard_light_fn, multiply_fn, screen_fn);
nb = fn(lb, rb, ab, hard_light_fn, multiply_fn, screen_fn);
} else if constexpr (M == BlendMode::darken) {
auto fn = blend_helper<BlendMode::darken>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
} else if constexpr (M == BlendMode::lighten) {
auto fn = blend_helper<BlendMode::lighten>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
} else if constexpr (M == BlendMode::colorDodge) {
auto fn = blend_helper<BlendMode::colorDodge>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
} else if constexpr (M == BlendMode::colorBurn) {
auto fn = blend_helper<BlendMode::colorDodge>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
} else if constexpr (M == BlendMode::hardLight) {
auto fn = blend_helper<BlendMode::hardLight>();
auto multiply_fn = blend_helper<BlendMode::multiply>();
auto screen_fn = blend_helper<BlendMode::screen>();
nr = fn(lr, rr, ab, multiply_fn, screen_fn);
ng = fn(lg, rg, ab, multiply_fn, screen_fn);
nb = fn(lb, rb, ab, multiply_fn, screen_fn);
} else if constexpr (M == BlendMode::softLight) {
auto fn = blend_helper<BlendMode::softLight>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
} else if constexpr (M == BlendMode::difference) {
auto fn = blend_helper<BlendMode::difference>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
} else if constexpr (M == BlendMode::exclusion) {
auto fn = blend_helper<BlendMode::exclusion>();
nr = fn(lr, rr, ab);
ng = fn(lg, rg, ab);
nb = fn(lb, rb, ab);
}
return RGBA(
to_pixel(nr),
to_pixel(ng),
to_pixel(nb),
alpha
);
}
constexpr auto blend(RGBA color, BlendMode mode) const noexcept -> RGBA {
switch (mode) {
case BlendMode::normal: return blend<BlendMode::normal>(color);
case BlendMode::multiply: return blend<BlendMode::multiply>(color);
case BlendMode::screen: return blend<BlendMode::screen>(color);
case BlendMode::overlay: return blend<BlendMode::overlay>(color);
case BlendMode::darken: return blend<BlendMode::darken>(color);
case BlendMode::lighten: return blend<BlendMode::lighten>(color);
case BlendMode::colorDodge: return blend<BlendMode::colorDodge>(color);
case BlendMode::colorBurn: return blend<BlendMode::colorBurn>(color);
case BlendMode::hardLight: return blend<BlendMode::hardLight>(color);
case BlendMode::softLight: return blend<BlendMode::softLight>(color);
case BlendMode::difference: return blend<BlendMode::difference>(color);
case BlendMode::exclusion: return blend<BlendMode::exclusion>(color);
}
}
private:
pixel_t m_data[4]{};
};
struct HSLA {
using pixel_t = float;
using pixels_t = float[4];
// ensures pixel to be in range
template <unsigned min, unsigned max>
struct PixelWrapper {
pixel_t& p;
constexpr PixelWrapper& operator=(float val) noexcept {
p = std::clamp(val, float(min), float(max));
}
constexpr operator pixel_t() const noexcept { return p; }
};
constexpr HSLA() noexcept = default;
constexpr HSLA(HSLA const&) noexcept = default;
constexpr HSLA(HSLA &&) noexcept = default;
constexpr HSLA& operator=(HSLA const&) noexcept = default;
constexpr HSLA& operator=(HSLA &&) noexcept = default;
constexpr ~HSLA() noexcept = default;
constexpr HSLA(pixel_t h, pixel_t s, pixel_t l, pixel_t a = 100) noexcept
: m_data({ .hsla = { .h = h, .s = s, .l = l, .a = a } })
{}
constexpr HSLA(RGBA color) noexcept {
auto min = std::min({color.r(), color.g(), color.b()});
auto max = std::max({color.r(), color.g(), color.b()});
auto c = (max - min) / 255.f;
auto tr = float(color.r()) / 255;
auto tg = float(color.g()) / 255;
auto tb = float(color.b()) / 255;
auto ta = float(color.a()) / 255;
float hue = 0;
float s = 0;
auto l = ((max + min) / 2.f) / 255.f;
if (min == max) {
if (max == color.r()) {
auto seg = (tg - tb) / c;
auto shift = (seg < 0 ? 360.f : 0.f) / 60.f;
hue = seg + shift;
} else if (max == color.g()) {
auto seg = (tb - tr) / c;
auto shift = 120.f / 60.f;
hue = seg + shift;
} else {
auto seg = (tr - tg) / c;
auto shift = 240.f / 60.f;
hue = seg + shift;
}
s = c / (1 - std::abs(2 * l - 1));
}
hue = hue * 60.f + 360.f;
auto q = static_cast<float>(static_cast<int>(hue / 360.f));
hue -= q * 360.f;
m_data.hsla.h = hue;
m_data.hsla.s = s * 100.f;
m_data.hsla.l = l * 100.f;
m_data.hsla.a = ta * 100.f;
}
constexpr operator RGBA() const noexcept {
auto ts = s() / 100.f;
auto tl = l() / 100.f;
auto ta = a() / 100.f;
if (s() == 0) return RGBA(to_pixel(tl), to_pixel(ta));
auto th = h() / 360.f;
float const q = tl < 0.5 ? tl * (1 + ts) : tl + ts - tl * ts;
float const p = 2 * tl - q;
return RGBA(
to_pixel(convert_hue(p, q, th + 1.f / 3)),
to_pixel(convert_hue(p, q, th)),
to_pixel(convert_hue(p, q, th - 1.f / 3)),
to_pixel(ta)
);
}
constexpr auto blend(HSLA color, BlendMode mode) const noexcept -> HSLA {
auto lhs = RGBA(*this);
auto rhs = RGBA(color);
return HSLA(lhs.blend(rhs, mode));
}
constexpr auto h() const noexcept -> pixel_t { return m_data.hsla.h; }
constexpr auto s() const noexcept -> pixel_t { return m_data.hsla.s; }
constexpr auto l() const noexcept -> pixel_t { return m_data.hsla.l; }
constexpr auto a() const noexcept -> pixel_t { return m_data.hsla.a; }
constexpr auto h() noexcept -> PixelWrapper<0, 360> { return { m_data.hsla.h }; }
constexpr auto s() noexcept -> PixelWrapper<0, 100> { return { m_data.hsla.s }; }
constexpr auto l() noexcept -> PixelWrapper<0, 100> { return { m_data.hsla.l }; }
constexpr auto a() noexcept -> PixelWrapper<0, 100> { return { m_data.hsla.a }; }
private:
static constexpr auto to_pixel(float a) noexcept -> RGBA::pixel_t {
return static_cast<RGBA::pixel_t>(a * 255);
}
static constexpr auto convert_hue(float p, float q, float t) noexcept -> float {
t = t - (t > 1) + (t < 0);
if (t * 6 < 1) return p + (q - p) * 6 * t;
if (t * 2 < 1) return q;
if (t * 3 < 2) return p + (q - p) * (2.f / 3 - t) * 6;
return p;
}
private:
union {
struct {
pixel_t h{}; // hue: 0-360
pixel_t s{}; // saturation: 0-100%
pixel_t l{}; // lightness: 0-100%
pixel_t a{}; // alpha: 0-100%
} hsla;
pixels_t color;
} m_data{};
};
namespace detail {
template <PixelFormat F>
inline static constexpr auto parse_pixel_helper(RGBA color, std::uint8_t* out_ptr) noexcept {
if constexpr (F == PixelFormat::rgba) {
out_ptr[0] = color.r();
out_ptr[1] = color.g();
out_ptr[2] = color.b();
out_ptr[3] = color.a();
} else if constexpr (F == PixelFormat::abgr) {
out_ptr[0] = color.a();
out_ptr[1] = color.b();
out_ptr[2] = color.g();
out_ptr[3] = color.r();
} else if constexpr (F == PixelFormat::rgb) {
out_ptr[0] = color.r();
out_ptr[1] = color.g();
out_ptr[2] = color.b();
} else if constexpr (F == PixelFormat::bgr) {
out_ptr[0] = color.b();
out_ptr[1] = color.g();
out_ptr[2] = color.r();
} else if constexpr (F == PixelFormat::ga) {
out_ptr[0] = color.r();
out_ptr[1] = color.a();
} else if constexpr (F == PixelFormat::ag) {
out_ptr[0] = color.a();
out_ptr[1] = color.r();
} else {
out_ptr[0] = color.r();
}
}
template <PixelFormat F>
inline static constexpr auto parse_pixel_helper(std::uint8_t const* in_ptr) noexcept -> RGBA {
if constexpr (F == PixelFormat::rgba) {
return {
in_ptr[0],
in_ptr[1],
in_ptr[2],
in_ptr[3]
};
} else if constexpr (F == PixelFormat::abgr) {
return {
in_ptr[3],
in_ptr[2],
in_ptr[1],
in_ptr[0]
};
} else if constexpr (F == PixelFormat::rgb) {
return {
in_ptr[0],
in_ptr[1],
in_ptr[2],
0xff
};
} else if constexpr (F == PixelFormat::bgr) {
return {
in_ptr[2],
in_ptr[1],
in_ptr[0],
0xff
};
} else if constexpr (F == PixelFormat::ga) {
return {
in_ptr[0],
in_ptr[1],
};
} else if constexpr (F == PixelFormat::ag) {
return {
in_ptr[1],
in_ptr[0],
};
} else {
return { in_ptr[0], 0xff };
}
}
} // namespace detail
inline static constexpr auto get_pixel_format_channel(PixelFormat format) noexcept -> std::size_t {
switch (format) {
case PixelFormat::rgba: case PixelFormat::abgr: return 4u;
case PixelFormat::rgb: case PixelFormat::bgr: return 3u;
case PixelFormat::ga: case PixelFormat::ag: return 2u;
case PixelFormat::g: return 1u;
}
assert(false && "unreachable");
}
struct PixelBuf {
private:
public:
using value_type = RGBA;
using base_type = Matrix<value_type>;
using pointer = typename base_type::pointer;
using const_pointer = typename base_type::const_pointer;
using reference = typename base_type::reference;
using const_reference = typename base_type::const_reference;
using iterator = typename base_type::iterator;
using const_iterator = typename base_type::const_iterator;
using reverse_iterator = typename base_type::reverse_iterator;
using const_reverse_iterator = typename base_type::const_reverse_iterator;
using difference_type = typename base_type::difference_type;
using size_type = typename base_type::size_type;
PixelBuf(size_type r, size_type c)
: m_data(r, c)
{}
PixelBuf(size_type r, size_type c, RGBA color)
: m_data(r, c, color)
{}
PixelBuf(std::uint8_t const* in, size_type r, size_type c, PixelFormat format = PixelFormat::rgba)
: PixelBuf(r, c)
{
assert(in != nullptr);
switch (format) {
case PixelFormat::rgba: from_helper<PixelFormat::rgba>(in, data(), size()); break;
case PixelFormat::abgr: from_helper<PixelFormat::abgr>(in, data(), size()); break;
case PixelFormat::rgb: from_helper<PixelFormat::rgb >(in, data(), size()); break;
case PixelFormat::bgr: from_helper<PixelFormat::bgr >(in, data(), size()); break;
case PixelFormat::ga: from_helper<PixelFormat::ga >(in, data(), size()); break;
case PixelFormat::ag: from_helper<PixelFormat::ag >(in, data(), size()); break;
case PixelFormat::g: from_helper<PixelFormat::g >(in, data(), size()); break;
}
}
PixelBuf() noexcept = default;
PixelBuf(PixelBuf const&) = default;
PixelBuf(PixelBuf &&) noexcept = default;
PixelBuf& operator=(PixelBuf const&) = default;
PixelBuf& operator=(PixelBuf &&) noexcept = default;
~PixelBuf() = default;
constexpr auto size() const noexcept -> size_type { return m_data.size(); }
constexpr auto rows() const noexcept -> size_type { return m_data.rows(); }
constexpr auto cols() const noexcept -> size_type { return m_data.cols(); }
constexpr auto data() noexcept -> pointer { return m_data.data(); }
constexpr auto data() const noexcept -> const_pointer { return m_data.data(); }
auto to_raw_buf() noexcept -> std::uint8_t* { return reinterpret_cast<std::uint8_t*>(data()); }
auto to_raw_buf() const noexcept -> std::uint8_t const* { return reinterpret_cast<std::uint8_t const*>(data()); }
constexpr auto raw_buf_size() const noexcept { return size() * sizeof(RGBA); }
constexpr auto begin() noexcept -> iterator { return m_data.begin(); }
constexpr auto end() noexcept -> iterator { return m_data.end(); }
constexpr auto begin() const noexcept -> const_iterator { return m_data.begin(); }
constexpr auto end() const noexcept -> const_iterator { return m_data.end(); }
constexpr auto rbegin() noexcept -> reverse_iterator { return m_data.rbegin(); }
constexpr auto rend() noexcept -> reverse_iterator { return m_data.rend(); }
constexpr auto rbegin() const noexcept -> const_reverse_iterator { return m_data.rbegin(); }
constexpr auto rend() const noexcept -> const_reverse_iterator { return m_data.rend(); }
constexpr decltype(auto) operator[](size_type r) noexcept { return m_data[r]; }
constexpr decltype(auto) operator[](size_type r) const noexcept { return m_data[r]; }
constexpr auto operator()(size_type r, size_type c) noexcept -> reference { return m_data(r, c); }
constexpr auto operator()(size_type r, size_type c) const noexcept -> const_reference { return m_data(r, c); }
constexpr auto fill(RGBA color) noexcept -> void {
std::fill(begin(), end(), color);
}
constexpr auto copy_to(std::uint8_t* out, PixelFormat format = PixelFormat::rgba) const noexcept {
assert(out != nullptr);
switch (format) {
case PixelFormat::rgba: copy_to_helper<PixelFormat::rgba>(data(), out, size());return;
case PixelFormat::abgr: copy_to_helper<PixelFormat::abgr>(data(), out, size());return;
case PixelFormat::rgb: copy_to_helper<PixelFormat::rgb >(data(), out, size());return;
case PixelFormat::bgr: copy_to_helper<PixelFormat::bgr >(data(), out, size());return;
case PixelFormat::ga: copy_to_helper<PixelFormat::ga >(data(), out, size());return;
case PixelFormat::ag: copy_to_helper<PixelFormat::ag >(data(), out, size());return;
case PixelFormat::g: copy_to_helper<PixelFormat::g >(data(), out, size());return;
}
assert(false && "unreachable");
}
private:
template <PixelFormat F>
constexpr auto copy_to_helper(const_pointer in, std::uint8_t* out, size_type size) const noexcept -> void {
constexpr auto channels = get_pixel_format_channel(F);
for (auto i = size_type{}; i < size; ++i) {
detail::parse_pixel_helper<F>(in[i], out + i * channels);
}
}
template <PixelFormat F>
constexpr auto from_helper(std::uint8_t const* in, pointer out, size_type size) const noexcept -> void {
constexpr auto channels = get_pixel_format_channel(F);
for (auto i = size_type{}; i < size; ++i) {
out[i] = detail::parse_pixel_helper<F>(in + i * channels);
}
}
private:
base_type m_data;
};
} // namespace amt
#include <format>
namespace std {
template <>
struct formatter<amt::RGBA> {
constexpr auto parse(format_parse_context& ctx) {
return ctx.begin();
}
auto format(amt::RGBA const& color, auto& ctx) const {
return format_to(ctx.out(), "rgba({}, {}, {}, {})", color.r(), color.g(), color.b(), color.a());
}
};
template <>
struct formatter<amt::HSLA> {
constexpr auto parse(format_parse_context& ctx) {
return ctx.begin();
}
auto format(amt::HSLA const& color, auto& ctx) const {
return format_to(ctx.out(), "hsla({:.1f}deg, {:.1f}%, {:.1f}%, {:.1f}%)", color.h(), color.s(), color.l(), color.a());
}
};
template <>
struct formatter<amt::PixelBuf> {
bool hsla = false;
constexpr auto parse(format_parse_context& ctx) {
auto it = ctx.begin();
while (it != ctx.end() && *it != '}') {
if (*it == 'h') hsla = true;
++it;
}
return it;
}
auto format(amt::PixelBuf const& buf, auto& ctx) const {
std::string s = "[\n";
for (auto r = std::size_t{}; r < buf.rows(); ++r) {
for (auto c = std::size_t{}; c < buf.cols(); ++c) {
auto color = buf(r, c);
if (hsla) s += std::format("{}, ", amt::HSLA(color));
else s += std::format("{}, ", color);
}
s += '\n';
}
s += "]";
return format_to(ctx.out(), "{}", s);
}
};
} // namespace std
#endif // AMT_PIXEL_HPP