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/*************************************************************************/
/* noise.h */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* https://godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md). */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#ifndef NOISE_H
#define NOISE_H
#include "core/io/image.h"
class Noise : public Resource {
GDCLASS(Noise, Resource);
// Helper struct for get_seamless_image(). See comments in .cpp for usage.
template <typename T>
struct img_buff {
T *img;
int width; // Array dimensions & default modulo for image.
int height;
int offset_x; // Offset index location on image (wrapped by specified modulo).
int offset_y;
int alt_width; // Alternate module for image.
int alt_height;
enum ALT_MODULO {
DEFAULT = 0,
ALT_X,
ALT_Y,
ALT_XY
};
// Multi-dimensional array indexer (e.g. img[x][y]) that supports multiple modulos.
T &operator()(int x, int y, ALT_MODULO mode = DEFAULT) {
switch (mode) {
case ALT_XY:
return img[(x + offset_x) % alt_width + ((y + offset_y) % alt_height) * width];
case ALT_X:
return img[(x + offset_x) % alt_width + ((y + offset_y) % height) * width];
case ALT_Y:
return img[(x + offset_x) % width + ((y + offset_y) % alt_height) * width];
default:
return img[(x + offset_x) % width + ((y + offset_y) % height) * width];
}
}
};
union l2c {
uint32_t l;
uint8_t c[4];
struct {
uint8_t r;
uint8_t g;
uint8_t b;
uint8_t a;
};
};
template <typename T>
Ref<Image> _generate_seamless_image(Ref<Image> p_src, int p_width, int p_height, bool p_invert, real_t p_blend_skirt) {
/*
To make a seamless image, we swap the quadrants so the edges are perfect matches.
We initially get a 10% larger image so we have an overlap we can use to blend over the seams.
Noise::img_buff::operator() acts as a multi-dimensional array indexer.
It does the array math, translates between the flipped and non-flipped quadrants, and manages offsets and modulos.
Here is how the larger source image and final output image map to each other:
Output size = p_width*p_height Source w/ extra 10% skirt `s` size = src_width*src_height
Q1 Q2 Q4 Q3 s1
Q3 Q4 Q2 Q1 s2
s5 s4 s3
All of the loops use output coordinates, so Output:Q1 == Source:Q1
Ex: Output(half_width, half_height) [the midpoint, corner of Q1/Q4] =>
on Source it's translated to
corner of Q1/s3 unless the ALT_XY modulo moves it to Q4
*/
int skirt_width = MAX(1, p_width * p_blend_skirt);
int skirt_height = MAX(1, p_height * p_blend_skirt);
int src_width = p_width + skirt_width;
int src_height = p_height + skirt_height;
int half_width = p_width * .5;
int half_height = p_height * .5;
int skirt_edge_x = half_width + skirt_width;
int skirt_edge_y = half_height + skirt_height;
Vector<uint8_t> dest;
dest.resize(p_width * p_height * Image::get_format_pixel_size(p_src->get_format()));
img_buff<T> rd_src = {
(T *)p_src->get_data().ptr(),
src_width, src_height,
half_width, half_height,
p_width, p_height
};
// `wr` is setup for straight x/y coordinate array access.
img_buff<T> wr = {
(T *)dest.ptrw(),
p_width, p_height,
0, 0, 0, 0
};
// `rd_dest` is a readable pointer to `wr`, i.e. what has already been written to the output buffer.
img_buff<T> rd_dest = {
(T *)dest.ptr(),
p_width, p_height,
0, 0, 0, 0
};
// Swap the quadrants to make edges seamless.
for (int y = 0; y < p_height; y++) {
for (int x = 0; x < p_width; x++) {
// rd_src has a half offset and the shorter modulo ignores the skirt.
// It reads and writes in Q1-4 order (see map above), skipping the skirt.
wr(x, y) = rd_src(x, y, img_buff<T>::ALT_XY);
}
}
// Blend the vertical skirt over the middle seam.
for (int x = half_width; x < skirt_edge_x; x++) {
int alpha = 255 * (1 - Math::smoothstep(.1f, .9f, float(x - half_width) / float(skirt_width)));
for (int y = 0; y < p_height; y++) {
// Skip the center square
if (y == half_height) {
y = skirt_edge_y - 1;
} else {
// Starts reading at s2, ALT_Y skips s3, and continues with s1.
wr(x, y) = _alpha_blend<T>(rd_dest(x, y), rd_src(x, y, img_buff<T>::ALT_Y), alpha);
}
}
}
// Blend the horizontal skirt over the middle seam.
for (int y = half_height; y < skirt_edge_y; y++) {
int alpha = 255 * (1 - Math::smoothstep(.1f, .9f, float(y - half_height) / float(skirt_height)));
for (int x = 0; x < p_width; x++) {
// Skip the center square
if (x == half_width) {
x = skirt_edge_x - 1;
} else {
// Starts reading at s4, skips s3, continues with s5.
wr(x, y) = _alpha_blend<T>(rd_dest(x, y), rd_src(x, y, img_buff<T>::ALT_X), alpha);
}
}
}
// Fill in the center square. Wr starts at the top left of Q4, which is the equivalent of the top left of s3, unless a modulo is used.
for (int y = half_height; y < skirt_edge_y; y++) {
for (int x = half_width; x < skirt_edge_x; x++) {
int xpos = 255 * (1 - Math::smoothstep(.1f, .9f, float(x - half_width) / float(skirt_width)));
int ypos = 255 * (1 - Math::smoothstep(.1f, .9f, float(y - half_height) / float(skirt_height)));
// Blend s3(Q1) onto s5(Q2) for the top half.
T top_blend = _alpha_blend<T>(rd_src(x, y, img_buff<T>::ALT_X), rd_src(x, y, img_buff<T>::DEFAULT), xpos);
// Blend s1(Q3) onto Q4 for the bottom half.
T bottom_blend = _alpha_blend<T>(rd_src(x, y, img_buff<T>::ALT_XY), rd_src(x, y, img_buff<T>::ALT_Y), xpos);
// Blend the top half onto the bottom half.
wr(x, y) = _alpha_blend<T>(bottom_blend, top_blend, ypos);
}
}
Ref<Image> image = memnew(Image(p_width, p_height, false, p_src->get_format(), dest));
p_src.unref();
return image;
}
template <typename T>
T _alpha_blend(T p_bg, T p_fg, int p_alpha) const {
l2c fg, bg, out;
fg.l = p_fg;
bg.l = p_bg;
uint16_t alpha;
uint16_t inv_alpha;
// If no alpha argument specified, use the alpha channel in the color
if (p_alpha == -1) {
alpha = fg.c[3] + 1;
inv_alpha = 256 - fg.c[3];
} else {
alpha = p_alpha + 1;
inv_alpha = 256 - p_alpha;
}
out.c[0] = (uint8_t)((alpha * fg.c[0] + inv_alpha * bg.c[0]) >> 8);
out.c[1] = (uint8_t)((alpha * fg.c[1] + inv_alpha * bg.c[1]) >> 8);
out.c[2] = (uint8_t)((alpha * fg.c[2] + inv_alpha * bg.c[2]) >> 8);
out.c[3] = 0xFF;
return out.l;
}
protected:
static void _bind_methods();
public:
// Virtual destructor so we can delete any Noise derived object when referenced as a Noise*.
virtual ~Noise() {}
virtual real_t get_noise_1d(real_t p_x) = 0;
virtual real_t get_noise_2dv(Vector2 p_v) = 0;
virtual real_t get_noise_2d(real_t p_x, real_t p_y) = 0;
virtual real_t get_noise_3dv(Vector3 p_v) = 0;
virtual real_t get_noise_3d(real_t p_x, real_t p_y, real_t p_z) = 0;
virtual Ref<Image> get_image(int p_width, int p_height, bool p_invert = false) = 0;
virtual Ref<Image> get_seamless_image(int p_width, int p_height, bool p_invert = false, real_t p_blend_skirt = 0.1);
};
#endif // NOISE_H
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