/* -*- mode: c++; c-basic-offset: 4 -*- */

#ifndef MPL_RESAMPLE_H

#define MPL_RESAMPLE_H

#define MPL_DISABLE_AGG_GRAY_CLIPPING

#include "agg_image_accessors.h"

#include "agg_path_storage.h"

#include "agg_pixfmt_gray.h"

#include "agg_pixfmt_rgba.h"

#include "agg_renderer_base.h"

#include "agg_renderer_scanline.h"

#include "agg_rasterizer_scanline_aa.h"

#include "agg_scanline_u.h"

#include "agg_span_allocator.h"

#include "agg_span_converter.h"

#include "agg_span_image_filter_gray.h"

#include "agg_span_image_filter_rgba.h"

#include "agg_span_interpolator_adaptor.h"

#include "agg_span_interpolator_linear.h"

#include "agg_workaround.h"

// Based on:

//----------------------------------------------------------------------------

// Anti-Grain Geometry - Version 2.4

// Copyright (C) 2002-2005 Maxim Shemanarev (http://antigrain.com/)

//

// Permission to copy, use, modify, sell and distribute this software

// is granted provided this copyright notice appears in all copies.

// This software is provided "as is" without express or implied

// warranty, and with no claim as to its suitability for any purpose.

//

//----------------------------------------------------------------------------

// Contact: [email protected]

// [email protected]

// http://antigrain.com/

//----------------------------------------------------------------------------

//

// Adaptation for high precision colors has been sponsored by

// Liberty Technology Systems, Inc., visit http://lib-sys.com

//

// Liberty Technology Systems, Inc. is the provider of

// PostScript and PDF technology for software developers.

//

//===================================================================gray64

namespace agg

{

struct gray64

{

typedef double value_type;

typedef double calc_type;

typedef double long_type;

typedef gray64 self_type;

value_type v;

value_type a;

//--------------------------------------------------------------------

gray64() = default;

//--------------------------------------------------------------------

explicit gray64(value_type v_, value_type a_ = 1) : v(v_), a(a_) {}

//--------------------------------------------------------------------

gray64(const self_type& c, value_type a_) : v(c.v), a(a_) {}

//--------------------------------------------------------------------

gray64(const gray64& c) = default;

//--------------------------------------------------------------------

static AGG_INLINE double to_double(value_type a)

{

return a;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type from_double(double a)

{

return value_type(a);

}

//--------------------------------------------------------------------

static AGG_INLINE value_type empty_value()

{

return 0;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type full_value()

{

return 1;

}

//--------------------------------------------------------------------

AGG_INLINE bool is_transparent() const

{

return a <= 0;

}

//--------------------------------------------------------------------

AGG_INLINE bool is_opaque() const

{

return a >= 1;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type invert(value_type x)

{

return 1 - x;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type multiply(value_type a, value_type b)

{

return value_type(a * b);

}

//--------------------------------------------------------------------

static AGG_INLINE value_type demultiply(value_type a, value_type b)

{

return (b == 0) ? 0 : value_type(a / b);

}

//--------------------------------------------------------------------

template<typename T>

static AGG_INLINE T downscale(T a)

{

return a;

}

//--------------------------------------------------------------------

template<typename T>

static AGG_INLINE T downshift(T a, unsigned n)

{

return n > 0 ? a / (1 << n) : a;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type mult_cover(value_type a, cover_type b)

{

return value_type(a * b / cover_mask);

}

//--------------------------------------------------------------------

static AGG_INLINE cover_type scale_cover(cover_type a, value_type b)

{

return cover_type(uround(a * b));

}

//--------------------------------------------------------------------

// Interpolate p to q by a, assuming q is premultiplied by a.

static AGG_INLINE value_type prelerp(value_type p, value_type q, value_type a)

{

return (1 - a) * p + q; // more accurate than "p + q - p * a"

}

//--------------------------------------------------------------------

// Interpolate p to q by a.

static AGG_INLINE value_type lerp(value_type p, value_type q, value_type a)

{

// The form "p + a * (q - p)" avoids a multiplication, but may produce an

// inaccurate result. For example, "p + (q - p)" may not be exactly equal

// to q. Therefore, stick to the basic expression, which at least produces

// the correct result at either extreme.

return (1 - a) * p + a * q;

}

//--------------------------------------------------------------------

self_type& clear()

{

v = a = 0;

return *this;

}

//--------------------------------------------------------------------

self_type& transparent()

{

a = 0;

return *this;

}

//--------------------------------------------------------------------

self_type& opacity(double a_)

{

if (a_ < 0) a = 0;

else if (a_ > 1) a = 1;

else a = value_type(a_);

return *this;

}

//--------------------------------------------------------------------

double opacity() const

{

return a;

}

//--------------------------------------------------------------------

self_type& premultiply()

{

if (a < 0) v = 0;

else if(a < 1) v *= a;

return *this;

}

//--------------------------------------------------------------------

self_type& demultiply()

{

if (a < 0) v = 0;

else if (a < 1) v /= a;

return *this;

}

//--------------------------------------------------------------------

self_type gradient(self_type c, double k) const

{

return self_type(

value_type(v + (c.v - v) * k),

value_type(a + (c.a - a) * k));

}

//--------------------------------------------------------------------

static self_type no_color() { return self_type(0,0); }

};

//====================================================================rgba32

struct rgba64

{

typedef double value_type;

typedef double calc_type;

typedef double long_type;

typedef rgba64 self_type;

value_type r;

value_type g;

value_type b;

value_type a;

//--------------------------------------------------------------------

rgba64() = default;

//--------------------------------------------------------------------

rgba64(value_type r_, value_type g_, value_type b_, value_type a_= 1) :

r(r_), g(g_), b(b_), a(a_) {}

//--------------------------------------------------------------------

rgba64(const self_type& c, float a_) :

r(c.r), g(c.g), b(c.b), a(a_) {}

//--------------------------------------------------------------------

rgba64(const rgba& c) :

r(value_type(c.r)), g(value_type(c.g)), b(value_type(c.b)), a(value_type(c.a)) {}

//--------------------------------------------------------------------

operator rgba() const

{

return rgba(r, g, b, a);

}

//--------------------------------------------------------------------

static AGG_INLINE double to_double(value_type a)

{

return a;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type from_double(double a)

{

return value_type(a);

}

//--------------------------------------------------------------------

static AGG_INLINE value_type empty_value()

{

return 0;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type full_value()

{

return 1;

}

//--------------------------------------------------------------------

AGG_INLINE bool is_transparent() const

{

return a <= 0;

}

//--------------------------------------------------------------------

AGG_INLINE bool is_opaque() const

{

return a >= 1;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type invert(value_type x)

{

return 1 - x;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type multiply(value_type a, value_type b)

{

return value_type(a * b);

}

//--------------------------------------------------------------------

static AGG_INLINE value_type demultiply(value_type a, value_type b)

{

return (b == 0) ? 0 : value_type(a / b);

}

//--------------------------------------------------------------------

template<typename T>

static AGG_INLINE T downscale(T a)

{

return a;

}

//--------------------------------------------------------------------

template<typename T>

static AGG_INLINE T downshift(T a, unsigned n)

{

return n > 0 ? a / (1 << n) : a;

}

//--------------------------------------------------------------------

static AGG_INLINE value_type mult_cover(value_type a, cover_type b)

{

return value_type(a * b / cover_mask);

}

//--------------------------------------------------------------------

static AGG_INLINE cover_type scale_cover(cover_type a, value_type b)

{

return cover_type(uround(a * b));

}

//--------------------------------------------------------------------

// Interpolate p to q by a, assuming q is premultiplied by a.

static AGG_INLINE value_type prelerp(value_type p, value_type q, value_type a)

{

return (1 - a) * p + q; // more accurate than "p + q - p * a"

}

//--------------------------------------------------------------------

// Interpolate p to q by a.

static AGG_INLINE value_type lerp(value_type p, value_type q, value_type a)

{

// The form "p + a * (q - p)" avoids a multiplication, but may produce an

// inaccurate result. For example, "p + (q - p)" may not be exactly equal

// to q. Therefore, stick to the basic expression, which at least produces

// the correct result at either extreme.

return (1 - a) * p + a * q;

}

//--------------------------------------------------------------------

self_type& clear()

{

r = g = b = a = 0;

return *this;

}

//--------------------------------------------------------------------

self_type& transparent()

{

a = 0;

return *this;

}

//--------------------------------------------------------------------

AGG_INLINE self_type& opacity(double a_)

{

if (a_ < 0) a = 0;

else if (a_ > 1) a = 1;

else a = value_type(a_);

return *this;

}

//--------------------------------------------------------------------

double opacity() const

{

return a;

}

//--------------------------------------------------------------------

AGG_INLINE self_type& premultiply()

{

if (a < 1)

{

if (a <= 0)

{

r = g = b = 0;

}

else

{

r *= a;

g *= a;

b *= a;

}

}

return *this;

}

//--------------------------------------------------------------------

AGG_INLINE self_type& demultiply()

{

if (a < 1)

{

if (a <= 0)

{

r = g = b = 0;

}

else

{

r /= a;

g /= a;

b /= a;

}

}

return *this;

}

//--------------------------------------------------------------------

AGG_INLINE self_type gradient(const self_type& c, double k) const

{

self_type ret;

ret.r = value_type(r + (c.r - r) * k);

ret.g = value_type(g + (c.g - g) * k);

ret.b = value_type(b + (c.b - b) * k);

ret.a = value_type(a + (c.a - a) * k);

return ret;

}

//--------------------------------------------------------------------

AGG_INLINE void add(const self_type& c, unsigned cover)

{

if (cover == cover_mask)

{

if (c.is_opaque())

{

*this = c;

return;

}

else

{

r += c.r;

g += c.g;

b += c.b;

a += c.a;

}

}

else

{

r += mult_cover(c.r, cover);

g += mult_cover(c.g, cover);

b += mult_cover(c.b, cover);

a += mult_cover(c.a, cover);

}

if (a > 1) a = 1;

if (r > a) r = a;

if (g > a) g = a;

if (b > a) b = a;

}

//--------------------------------------------------------------------

static self_type no_color() { return self_type(0,0,0,0); }

};

}

typedef enum {

NEAREST,

BILINEAR,

BICUBIC,

SPLINE16,

SPLINE36,

HANNING,

HAMMING,

HERMITE,

KAISER,

QUADRIC,

CATROM,

GAUSSIAN,

BESSEL,

MITCHELL,

SINC,

LANCZOS,

BLACKMAN,

} interpolation_e;

// T is rgba if and only if it has a T::r field.

template<typename T, typename = void> struct is_grayscale : std::true_type {};

template<typename T> struct is_grayscale<T, std::void_t<decltype(T::r)>> : std::false_type {};

template<typename T> constexpr bool is_grayscale_v = is_grayscale<T>::value;

template<typename color_type>

struct type_mapping

{

using blender_type = std::conditional_t<

is_grayscale_v<color_type>,

agg::blender_gray<color_type>,

std::conditional_t<

std::is_same_v<color_type, agg::rgba8>,

fixed_blender_rgba_plain<color_type, agg::order_rgba>,

agg::blender_rgba_pre<color_type, agg::order_rgba>

>

>;

using pixfmt_type = std::conditional_t<

is_grayscale_v<color_type>,

agg::pixfmt_alpha_blend_gray<blender_type, agg::rendering_buffer>,

agg::pixfmt_alpha_blend_rgba<blender_type, agg::rendering_buffer>

>;

template<typename A> using span_gen_affine_type = std::conditional_t<

is_grayscale_v<color_type>,

agg::span_image_resample_gray_affine<A>,

agg::span_image_resample_rgba_affine<A>

>;

template<typename A, typename B> using span_gen_filter_type = std::conditional_t<

is_grayscale_v<color_type>,

agg::span_image_filter_gray<A, B>,

agg::span_image_filter_rgba<A, B>

>;

template<typename A, typename B> using span_gen_nn_type = std::conditional_t<

is_grayscale_v<color_type>,

agg::span_image_filter_gray_nn<A, B>,

agg::span_image_filter_rgba_nn<A, B>

>;

};

template<typename color_type>

class span_conv_alpha

{

public:

span_conv_alpha(const double alpha) :

m_alpha(alpha)

{

}

void prepare() {}

void generate(color_type* span, int x, int y, unsigned len) const

{

if (m_alpha != 1.0) {

do {

span->a = static_cast<typename color_type::value_type>(

static_cast<typename color_type::calc_type>(span->a) * m_alpha);

++span;

} while (--len);

}

}

private:

const double m_alpha;

};

/* A class to use a lookup table for a transformation */

class lookup_distortion

{

public:

lookup_distortion(const double *mesh, int in_width, int in_height,

int out_width, int out_height, bool edge_aligned_subpixels) :

m_mesh(mesh),

m_in_width(in_width),

m_in_height(in_height),

m_out_width(out_width),

m_out_height(out_height),

m_edge_aligned_subpixels(edge_aligned_subpixels)

{}

void calculate(int* x, int* y) {

if (m_mesh) {

// Nearest-neighbor interpolation needs edge-aligned subpixels

// All other interpolation approaches need center-aligned subpixels

double offset = m_edge_aligned_subpixels ? 0 : 0.5;

double dx = double(*x) / agg::image_subpixel_scale;

double dy = double(*y) / agg::image_subpixel_scale;

if (dx >= 0 && dx < m_out_width &&

dy >= 0 && dy < m_out_height) {

const double *coord = m_mesh + (int(dy) * m_out_width + int(dx)) * 2;

// Add a tiny fudge amount to account for numerical precision loss

*x = int(coord[0] * agg::image_subpixel_scale + offset + 1e-8);

*y = int(coord[1] * agg::image_subpixel_scale + offset + 1e-8);

}

}

}

protected:

const double *m_mesh;

int m_in_width;

int m_in_height;

int m_out_width;

int m_out_height;

bool m_edge_aligned_subpixels;

};

struct resample_params_t {

interpolation_e interpolation;

bool is_affine;

agg::trans_affine affine;

const double *transform_mesh;

bool resample;

bool norm;

double radius;

double alpha;

};

static void get_filter(const resample_params_t &params,

agg::image_filter_lut &filter)

{

switch (params.interpolation) {

case NEAREST:

// Never should get here. Here to silence compiler warnings.

break;

case HANNING:

filter.calculate(agg::image_filter_hanning(), params.norm);

break;

case HAMMING:

filter.calculate(agg::image_filter_hamming(), params.norm);

break;

case HERMITE:

filter.calculate(agg::image_filter_hermite(), params.norm);

break;

case BILINEAR:

filter.calculate(agg::image_filter_bilinear(), params.norm);

break;

case BICUBIC:

filter.calculate(agg::image_filter_bicubic(), params.norm);

break;

case SPLINE16:

filter.calculate(agg::image_filter_spline16(), params.norm);

break;

case SPLINE36:

filter.calculate(agg::image_filter_spline36(), params.norm);

break;

case KAISER:

filter.calculate(agg::image_filter_kaiser(), params.norm);

break;

case QUADRIC:

filter.calculate(agg::image_filter_quadric(), params.norm);

break;

case CATROM:

filter.calculate(agg::image_filter_catrom(), params.norm);

break;

case GAUSSIAN:

filter.calculate(agg::image_filter_gaussian(), params.norm);

break;

case BESSEL:

filter.calculate(agg::image_filter_bessel(), params.norm);

break;

case MITCHELL:

filter.calculate(agg::image_filter_mitchell(), params.norm);

break;

case SINC:

filter.calculate(agg::image_filter_sinc(params.radius), params.norm);

break;

case LANCZOS:

filter.calculate(agg::image_filter_lanczos(params.radius), params.norm);

break;

case BLACKMAN:

filter.calculate(agg::image_filter_blackman(params.radius), params.norm);

break;

}

}

template<typename color_type>

void resample(

const void *input, int in_width, int in_height,

void *output, int out_width, int out_height,

resample_params_t &params)

{

using type_mapping_t = type_mapping<color_type>;

using input_pixfmt_t = typename type_mapping_t::pixfmt_type;

using output_pixfmt_t = typename type_mapping_t::pixfmt_type;

using renderer_t = agg::renderer_base<output_pixfmt_t>;

using rasterizer_t = agg::rasterizer_scanline_aa<agg::rasterizer_sl_clip_dbl>;

using scanline_t = agg::scanline32_u8;

using reflect_t = agg::wrap_mode_reflect;

using image_accessor_wrap_t = agg::image_accessor_wrap<input_pixfmt_t, reflect_t, reflect_t>;

using image_accessor_clip_t = agg::image_accessor_clip<input_pixfmt_t>;

using span_alloc_t = agg::span_allocator<color_type>;

using span_conv_alpha_t = span_conv_alpha<color_type>;

using nn_affine_interpolator_t = accurate_interpolator_affine_nn<>;

using affine_interpolator_t = agg::span_interpolator_linear<>;

using arbitrary_interpolator_t =

agg::span_interpolator_adaptor<agg::span_interpolator_linear<>, lookup_distortion>;

size_t itemsize = sizeof(color_type);

if (is_grayscale<color_type>::value) {

itemsize /= 2; // agg::grayXX includes an alpha channel which we don't have.

}

if (params.interpolation != NEAREST &&

params.is_affine &&

fabs(params.affine.sx) == 1.0 &&

fabs(params.affine.sy) == 1.0 &&

params.affine.shx == 0.0 &&

params.affine.shy == 0.0) {

params.interpolation = NEAREST;

}

span_alloc_t span_alloc;

rasterizer_t rasterizer;

scanline_t scanline;

span_conv_alpha_t conv_alpha(params.alpha);

agg::rendering_buffer input_buffer;

input_buffer.attach(

(unsigned char *)input, in_width, in_height, in_width * itemsize);

input_pixfmt_t input_pixfmt(input_buffer);

image_accessor_wrap_t input_accessor_wrap(input_pixfmt);

image_accessor_clip_t input_accessor_clip(input_pixfmt, color_type::no_color());

agg::rendering_buffer output_buffer;

output_buffer.attach(

(unsigned char *)output, out_width, out_height, out_width * itemsize);

output_pixfmt_t output_pixfmt(output_buffer);

renderer_t renderer(output_pixfmt);

agg::trans_affine inverted = params.affine;

inverted.invert();

rasterizer.clip_box(0, 0, out_width, out_height);

agg::path_storage path;

if (params.is_affine && params.interpolation != NEAREST) {

if (params.affine.shx != 0 || params.affine.shy != 0) {

path.move_to(0, 0);

path.line_to(in_width, 0);

path.line_to(in_width, in_height);

path.line_to(0, in_height);

path.close_polygon();

agg::conv_transform<agg::path_storage> rectangle(path, params.affine);

rasterizer.add_path(rectangle);

} else {

// If there is no shear/rotation, bump out the rendering edges that are

// within a half pixel of a full pixel so that axes are visually filled.

// This bumping out is equivalent to treating any edge pixel that is at

// least half-covered by the source as fully covered by the source.

double left = 0;

double right = in_width;

double bottom = 0;

double top = in_height;

params.affine.transform(&left, &bottom);

params.affine.transform(&right, &top);

if (left > right) { std::swap(left, right); }

if (bottom > top) { std::swap(top, bottom); }

// Add a tiny fudge amount to account for numerical precision loss

int rleft = agg::iround(left - 1e-8);

int rright = agg::iround(right + 1e-8);

int rbottom = agg::iround(bottom - 1e-8);

int rtop = agg::iround(top + 1e-8);

if (rleft < left) { left = rleft; }

if (rright > right) { right = rright; }

if (rbottom < bottom) { bottom = rbottom; }

if (rtop > top) { top = rtop; }

path.move_to(left, bottom);

path.line_to(right, bottom);

path.line_to(right, top);

path.line_to(left, top);

path.close_polygon();

rasterizer.add_path(path);

}

} else {

path.move_to(0, 0);

path.line_to(out_width, 0);

path.line_to(out_width, out_height);

path.line_to(0, out_height);

path.close_polygon();

rasterizer.add_path(path);

}

if (params.interpolation == NEAREST) {

if (params.is_affine) {

using span_gen_t = typename type_mapping_t::template span_gen_nn_type<image_accessor_clip_t, nn_affine_interpolator_t>;

using span_conv_t = agg::span_converter<span_gen_t, span_conv_alpha_t>;

using nn_renderer_t = agg::renderer_scanline_aa<renderer_t, span_alloc_t, span_conv_t>;

nn_affine_interpolator_t interpolator(inverted);

span_gen_t span_gen(input_accessor_clip, interpolator);

span_conv_t span_conv(span_gen, conv_alpha);

nn_renderer_t nn_renderer(renderer, span_alloc, span_conv);

agg::render_scanlines(rasterizer, scanline, nn_renderer);

} else {

using span_gen_t = typename type_mapping_t::template span_gen_nn_type<image_accessor_clip_t, arbitrary_interpolator_t>;

using span_conv_t = agg::span_converter<span_gen_t, span_conv_alpha_t>;

using nn_renderer_t = agg::renderer_scanline_aa<renderer_t, span_alloc_t, span_conv_t>;

lookup_distortion dist(

params.transform_mesh, in_width, in_height, out_width, out_height, true);

arbitrary_interpolator_t interpolator(inverted, dist);

span_gen_t span_gen(input_accessor_clip, interpolator);

span_conv_t span_conv(span_gen, conv_alpha);

nn_renderer_t nn_renderer(renderer, span_alloc, span_conv);

agg::render_scanlines(rasterizer, scanline, nn_renderer);

}

} else {

agg::image_filter_lut filter;

get_filter(params, filter);

if (params.is_affine && params.resample) {

using span_gen_t = typename type_mapping_t::template span_gen_affine_type<image_accessor_wrap_t>;

using span_conv_t = agg::span_converter<span_gen_t, span_conv_alpha_t>;

using int_renderer_t = agg::renderer_scanline_aa<renderer_t, span_alloc_t, span_conv_t>;

affine_interpolator_t interpolator(inverted);

span_gen_t span_gen(input_accessor_wrap, interpolator, filter);

span_conv_t span_conv(span_gen, conv_alpha);

int_renderer_t int_renderer(renderer, span_alloc, span_conv);

agg::render_scanlines(rasterizer, scanline, int_renderer);

} else {

using span_gen_t = typename type_mapping_t::template span_gen_filter_type<image_accessor_wrap_t, arbitrary_interpolator_t>;

using span_conv_t = agg::span_converter<span_gen_t, span_conv_alpha_t>;

using int_renderer_t = agg::renderer_scanline_aa<renderer_t, span_alloc_t, span_conv_t>;

lookup_distortion dist(

params.transform_mesh, in_width, in_height, out_width, out_height, false);

arbitrary_interpolator_t interpolator(inverted, dist);

span_gen_t span_gen(input_accessor_wrap, interpolator, filter);

span_conv_t span_conv(span_gen, conv_alpha);

int_renderer_t int_renderer(renderer, span_alloc, span_conv);

agg::render_scanlines(rasterizer, scanline, int_renderer);

}

}

}

#endif /* MPL_RESAMPLE_H */