472 lines
18 KiB
C++
472 lines
18 KiB
C++
/**
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* \file main.cpp
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* \brief implementation of the string art algorithm
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* \author GrumpyDeveloper (Sascha Nitsch)
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* \copyright 2023 Sascha Nitsch
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* Licensed under GPL3 or later license
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* https://contentnation.net/en/grumpydevelop/stringart
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* SPDX-FileCopyrightText: 2023 Sascha Nitsch (@grumpydevelop@contentnation.net) https://contentnation.net/en/grumpydevelop
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* SPDX-License-Identifier: GPL-3.0-or-later
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*
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*/
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// compile with
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/// g++ -march=native `Magick++-config --cxxflags --cppflags` -Wall -Werror -o main main.cpp -O3 `Magick++-config --ldflags --libs`
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#include <math.h>
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#include <Magick++.h>
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#include <string.h>
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#include <sys/time.h>
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#include <vector>
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#include <unordered_map>
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// which basic nail placement algorithms should be used
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// #define grid
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// #define multicircle
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#define circle
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/// the actual weight function to calculate how off we are to the target
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/// \param value current value
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/// \param target desired target
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/// \retval distance to target
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inline int64_t weightFunction(int16_t value, int16_t target) {
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return (value - target) * (value - target);
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}
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/// definition of a point for our dwarn line vector
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struct Point {
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/// x coordinate
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uint16_t x;
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/// y coordinate
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uint16_t y;
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/// color value
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uint8_t color;
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};
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/// typedef for a list of points tha make a line
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typedef std::vector<Point> td_pointsInLine;
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/// the line from src to dst, key = (src << 16) + dst
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typedef std::unordered_map<uint32_t, td_pointsInLine> td_linesFromSource;
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/// swaps two numbers
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/// \param a first number
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/// \param b second number
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inline void swap(int16_t* a , int16_t* b) {
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int16_t temp = *a;
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*a = *b;
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*b = temp;
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}
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/// return floating part of number
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/// \param x number to process
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/// \retval the data behind the dot
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inline float fPartOfNumber(float x) {
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if (x > 0) {
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return x - floor(x);
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}
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return x - (floor(x) + 1);
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}
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/// add given point to vector if col is > 0
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/// \param pil pointer to vector
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/// \param x x coordinate
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/// \param y y coordingte
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/// \param col color
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inline void pb(td_pointsInLine* pil, uint16_t x, uint16_t y, uint8_t col) {
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if (col > 0) {
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pil->push_back({x, y, col});
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}
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}
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/// draw line using Xiaolin Wu’s line algorithm
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/// \param x0 source x coordinate
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/// \param y0 source y coordinate
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/// \param x1 destination x coordinate
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/// \param y1 destination y coordinate
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/// \param color color to draw
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td_pointsInLine drawAALine(int16_t x0 , int16_t y0 , int16_t x1 , int16_t y1, uint8_t color) {
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td_pointsInLine pil;
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bool steep = abs(y1 - y0) > abs(x1 - x0);
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// swap the co-ordinates if slope > 1 or we
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// draw backwards
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if (steep) {
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swap(&x0, &y0);
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swap(&x1, &y1);
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}
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if (x0 > x1) {
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swap(&x0, &x1);
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swap(&y0, &y1);
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}
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// compute the slope
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float dx = x1 - x0;
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float dy = y1 - y0;
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float gradient = dy / dx;
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if (dx == 0.0) {
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gradient = 1;
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}
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int16_t xpxl1 = x0;
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int16_t xpxl2 = x1;
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float intersectY = y0;
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// main loop
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if (steep) {
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int16_t x;
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for (x = xpxl1 ; x <= xpxl2 ; ++x) {
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// pixel coverage is determined by fractional
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// part of y co-ordinate
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pb(&pil, static_cast<uint16_t>(intersectY), static_cast<uint16_t>(x), static_cast<uint8_t>(color * (1 - fPartOfNumber(intersectY))));
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if (intersectY >= 1) {
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pb(&pil, static_cast<uint16_t>(intersectY - 1), static_cast<uint16_t>(x), static_cast<uint8_t>(color * fPartOfNumber(intersectY)));
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}
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intersectY += gradient;
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}
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} else {
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int16_t x;
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for (x = xpxl1 ; x <= xpxl2 ; ++x) {
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// pixel coverage is determined by fractional
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// part of y co-ordinate
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pb(&pil, static_cast<uint16_t>(x), static_cast<uint16_t>(intersectY), static_cast<uint8_t>(color * (1 - fPartOfNumber(intersectY))));
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if (intersectY >= 1) {
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pb(&pil, static_cast<uint16_t>(x), static_cast<uint16_t>(intersectY - 1), static_cast<uint8_t>(color * fPartOfNumber(intersectY)));
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}
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intersectY += gradient;
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}
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}
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return pil;
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}
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/// \brief main entry point
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/// \param argc number of command line arguments
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/// \param argv command line arguments
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int main(int argc, char* argv[]) {
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if (argc != 8) {
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printf("usage: %s <image name> <resolution x> <resolution y> <number of nails> <max number of iterations> <penalty for duplicate path usage> <lineColor>\n", argv[0]);
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return 1;
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}
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// copy command line data to easier to use variables
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const char* imageName = argv[1];
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uint16_t resolutionX = atoi(argv[2]);
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uint16_t resolutionY = atoi(argv[3]);
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uint16_t numberOfNails = atoi(argv[4]);
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uint16_t maxIter = atoi(argv[5]);
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float duplicateFactor = atof(argv[6]);
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uint8_t lineColor = atoi(argv[7]);
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// our line storage
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td_linesFromSource linesFromSource;
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printf("res: %ix%i nails: %i maxIter: %i duplicatePenalty %.1f color: %i\n", resolutionX, resolutionY, numberOfNails, maxIter, duplicateFactor, lineColor);
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/// nail positions (x << 16) + y
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std::vector<uint32_t> nails;
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// for time measurement
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struct timeval tv1, tv2;
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gettimeofday(&tv1, NULL);
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// initialize image magick, load image and resize to target coordinates
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Magick::InitializeMagick(NULL);
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Magick::Image img(imageName);
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if (img.depth() != 8) {
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printf("only 8 bit images supported\n");
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return 1;
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}
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img.sample(Magick::Geometry(resolutionX, resolutionY));
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// fix potential size differences between requested and delivered size
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uint16_t realWidth = img.columns();
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uint16_t realHeight = img.rows();
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// position nails
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#ifdef circle
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for (uint16_t i = 0; i < numberOfNails; ++i) {
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float x = sin(2.0 * M_PI * i / numberOfNails) * (realWidth-1) / 2.0 + realWidth / 2.0;
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float y = cos(2.0 * M_PI * i / numberOfNails) * (realHeight-1) / 2.0 + realHeight / 2.0;
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nails.push_back((static_cast<uint32_t>(floor(x)) << 16) + static_cast<uint16_t>(floor(y)));
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}
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#endif
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#ifdef multicircle
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uint16_t count = numberOfNails/1.5;
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for (uint16_t i = 0; i < count; ++i) {
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float x = sin(2.0 * M_PI * i / count) * (realWidth-1) / 2.0 + realWidth / 2.0;
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float y = cos(2.0 * M_PI * i / count) * (realHeight-1) / 2.0 + realHeight / 2.0;
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nails.push_back((static_cast<uint32_t>(floor(x)) << 16) + static_cast<uint16_t>(floor(y)));
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}
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uint16_t width = realWidth/1.2 -1;
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uint16_t height = realHeight/1.2 -1;
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count = numberOfNails/1.5;
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for (uint16_t i = 0; i < count; ++i) {
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float x = sin(2.0 * M_PI * i / count) * (width-1) / 2.0 + realWidth / 2.0;
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float y = cos(2.0 * M_PI * i / count) * (height-1) / 2.0 + realHeight / 2.0;
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nails.push_back((static_cast<uint32_t>(floor(x)) << 16) + static_cast<uint16_t>(floor(y)));
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}
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width = realWidth/1.5 -1;
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height = realHeight/1.5 -1;
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count = numberOfNails/2;
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for (uint16_t i = 0; i < count; ++i) {
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float x = sin(2.0 * M_PI * i / count) * (width-1) / 2.0 + realWidth / 2.0;
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float y = cos(2.0 * M_PI * i / count) * (height-1) / 2.0 + realHeight / 2.0;
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nails.push_back((static_cast<uint32_t>(floor(x)) << 16) + static_cast<uint16_t>(floor(y)));
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}
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width = realWidth/2 -1;
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height = realHeight/2 -1;
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count = numberOfNails/3;
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for (uint16_t i = 0; i < count; ++i) {
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float x = sin(2.0 * M_PI * i / count) * (width-1) / 2.0 + realWidth / 2.0;
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float y = cos(2.0 * M_PI * i / count) * (height-1) / 2.0 + realHeight / 2.0;
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nails.push_back((static_cast<uint32_t>(floor(x)) << 16) + static_cast<uint16_t>(floor(y)));
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}
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width = realWidth/3 -1;
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height = realHeight/3 -1;
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count = numberOfNails/4;
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for (uint16_t i = 0; i < count; ++i) {
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float x = sin(2.0 * M_PI * i / count) * (width-1) / 2.0 + realWidth / 2.0;
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float y = cos(2.0 * M_PI * i / count) * (height-1) / 2.0 + realHeight / 2.0;
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nails.push_back((static_cast<uint32_t>(floor(x)) << 16) + static_cast<uint16_t>(floor(y)));
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}
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width = realWidth/5 -1;
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height = realHeight/5 -1;
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count = numberOfNails/6;
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for (uint16_t i = 0; i < count; ++i) {
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float x = sin(2.0 * M_PI * i / count) * (width-1) / 2.0 + realWidth / 2.0;
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float y = cos(2.0 * M_PI * i / count) * (height-1) / 2.0 + realHeight / 2.0;
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nails.push_back((static_cast<uint32_t>(floor(x)) << 16) + static_cast<uint16_t>(floor(y)));
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}
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nails.push_back((static_cast<uint32_t>(floor(realWidth / 2.0)) << 16) + static_cast<uint16_t>(floor(realHeight / 2.0)));
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#endif
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#ifdef grid
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uint8_t sq_pins = sqrt(numberOfNails);
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float distX = static_cast<float>(realWidth - 1) / (sq_pins - 1);
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float distY = static_cast<float>(realHeight - 1) / (sq_pins - 1);
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for (uint16_t y = 0; y < sq_pins; ++y) {
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for (uint16_t x = 0; x < sq_pins; ++x) {
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nails.push_back((static_cast<uint32_t>(floor(distX * x)) << 16) + static_cast<uint16_t>(floor(distY * y)));
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}
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}
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#endif
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// number of nails might have been changed above or loaded (in the future)
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numberOfNails = nails.size();
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printf("num %i\n", numberOfNails);
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for (uint16_t src = 0; src < numberOfNails; ++src) {
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for (uint16_t dst = src + 1; dst < numberOfNails; ++dst) {
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td_pointsInLine pointsInLine = drawAALine(nails[src] >> 16, nails[src] & 0xFFFF, nails[dst] >> 16, nails[dst] & 0xFFFF, lineColor);
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linesFromSource.insert(std::make_pair((src << 16) + dst, pointsInLine));
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}
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}
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uint32_t channels = img.channels();
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printf("target image %i x %i x %i\n", realWidth, realHeight, channels);
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MagickCore::Quantum *pixels = img.getPixels(0, 0, realWidth, realHeight);
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uint8_t* targetState = reinterpret_cast<uint8_t*>(malloc(realWidth * realHeight));
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if (channels == 1) { // monochrome image
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for (uint32_t i = 0; i < realWidth * realHeight; ++i) {
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targetState[i] = pixels[i] >> 8;
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}
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} else if (channels == 2) { // color + alpha?
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for (uint32_t i = 0; i < realWidth * realHeight; ++i) {
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targetState[i] = pixels[i << 1] >> 8;
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}
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} else { // RGB or RGBA
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for (uint32_t i = 0; i < realWidth * realHeight; ++i) {
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targetState[i] = ((pixels[i*channels] + pixels[i*channels + 1] + pixels[i*channels + 2]) / 3) >> 8;
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}
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}
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#ifdef DEBUGIMG
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FILE* debugfh = fopen("debug.pnm", "wb");
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fprintf(debugfh, "P5\n# debug\n%i %i\n255\n", realWidth, realHeight);
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fwrite(targetState, 1, realWidth * realHeight, debugfh);
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fclose(debugfh);
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#endif
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// thread path
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std::vector<uint16_t> path;
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// add start position
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path.push_back(0);
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// a lookup of used paths to count repeats
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uint16_t usedpaths[numberOfNails][numberOfNails];
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bzero(usedpaths, numberOfNails * numberOfNails * 2);
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/// last thread end position
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int16_t lastPosition = 0;
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/// storage for the current state (all previous drawn threads)
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int16_t* currentState = reinterpret_cast<int16_t*>(malloc(realWidth * realHeight * 2));
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/// temp storage to save (current) best version, will be continously updated
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int16_t* bestState = reinterpret_cast<int16_t*>(malloc(realWidth * realHeight * 2));
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// clear states
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uint32_t widthXheight = realWidth * realHeight;
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for (uint32_t i = 0; i < widthXheight; ++i) {
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currentState[i] = 255;
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bestState[i] = 255;
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}
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// current iteration
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uint32_t iter = 0;
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// list of used nails with their counter
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uint8_t usedPins[numberOfNails] = {0};
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// number of continous jump tries if we got stuck
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uint16_t jumps = 0;
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/// total diff from currentState to targetState
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int64_t totalDiff = 0;
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// calculate inital difference
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for (uint32_t i = 0; i < widthXheight; ++i) {
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totalDiff += weightFunction(255, targetState[i]);
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}
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printf("start %li\n", totalDiff);
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while ((iter < maxIter) && jumps*2 < numberOfNails) {
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++iter;
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#ifdef SANITYCHECK
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int64_t sanity = 0;
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for (uint32_t Z = 0; Z < widthXheight; ++Z) {
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int16_t cur = currentState[Z];
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int16_t goal = targetState[Z];
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sanity += weightFunction(cur, goal);
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}
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if (sanity != totalDiff) {
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printf("%i: total: %li, sanity: %li, diff: %li\n", iter, totalDiff, sanity, sanity - totalDiff);
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}
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#endif
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/// current best difference
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int64_t realBestDiff = INT64_MAX;
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/// compensated diff includes penality when reusing paths
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int64_t compensatedBestDiff = INT64_MAX;
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int16_t bestTarget = -1;
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// printf("source %i\n", lastPosition); fflush(stdout);
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for (int16_t target = 0; target < numberOfNails; ++target) {
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if (target == lastPosition) continue;
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/// the diff on current lastPosition -> target
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int64_t testDiff = 0;
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uint16_t src = std::min(lastPosition, target);
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uint16_t dst = std::max(lastPosition, target);
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td_linesFromSource::const_iterator lttIter = linesFromSource.find((src << 16) + dst);
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// calculate difference to target
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// for each point
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td_pointsInLine::const_iterator pilIter = lttIter->second.begin();
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while (pilIter != lttIter->second.end()) {
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uint16_t x = (*pilIter).x;
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uint16_t y = (*pilIter).y;
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uint8_t sub = (*pilIter).color;
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uint32_t index = y * realWidth + x;
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int16_t cur = currentState[index];
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int16_t goal = targetState[index];
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// subtract previous error
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testDiff -= weightFunction(cur, goal);
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cur -= sub;
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// add new error
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testDiff += weightFunction(cur, goal);
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++pilIter;
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}
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float duplicatePenalty = (duplicateFactor != 1) ?
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pow(duplicateFactor, usedpaths[std::min(lastPosition, target)][std::max(lastPosition, target)])
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: 1;
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if ((testDiff / duplicatePenalty) < compensatedBestDiff) {
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// printf(" new best %i - %i(%i,%i) %li d %li\n", lastPosition, target, pos[target]>>16, pos[target]&0xffff, testDiff, totalDiff - testDiff);
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compensatedBestDiff = testDiff * duplicatePenalty;
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realBestDiff = testDiff;
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// a new best
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if (bestTarget != -1) {
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// printf("undo %i:%i\n", lastPosition, bestTarget);
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// undo previous best
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uint16_t tmpSrc = std::min(lastPosition, bestTarget);
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uint16_t tmpDst = std::max(lastPosition, bestTarget);
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td_linesFromSource::const_iterator tmpLfsIter = linesFromSource.find((tmpSrc << 16) + tmpDst);
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td_pointsInLine::const_iterator pilIter = tmpLfsIter->second.begin();
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while (pilIter != tmpLfsIter->second.end()) {
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uint16_t x = (*pilIter).x;
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uint16_t y = (*pilIter).y;
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uint32_t index = y * realWidth + x;
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int16_t cur = currentState[index];
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bestState[index] = cur;
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++pilIter;
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}
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}
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// apply current best
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td_pointsInLine::const_iterator pilIter = lttIter->second.begin();
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while (pilIter != lttIter->second.end()) {
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uint16_t x = (*pilIter).x;
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uint16_t y = (*pilIter).y;
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int16_t sub = (*pilIter).color;
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uint32_t index = y * realWidth + x;
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int16_t cur = currentState[index];
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cur -= sub;
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bestState[index] = cur;
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++pilIter;
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}
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bestTarget = target;
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}
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}
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if (realBestDiff >= 0) {
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// we got worse, jump to random place to continue
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// printf("j %3i %3i -> %3i(%4i, %4i) bestDiff %8li (%li) iter %i path %i\n", jumps, lastPosition, bestTarget, pos[bestTarget] >> 16, pos[bestTarget] & 0xFFFF, realBestDiff, totalDiff - realBestDiff, iter, usedpaths[std::min(lastPosition, bestTarget)][std::max(lastPosition, bestTarget)]);
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if (jumps) { // undo last jump, was not working anyway
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--usedPins[lastPosition];
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path.pop_back();
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}
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// select next target randomly (kind of, intentially producing the same numbers)
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bestTarget = random() % numberOfNails;
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path.push_back(bestTarget);
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lastPosition = bestTarget;
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++usedPins[bestTarget];
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++jumps;
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--iter;
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// fix bestState, easier to copy over than manually reversing. should only happen a few times anyway
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memcpy(bestState, currentState, widthXheight * 2);
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continue;
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||
}
|
||
/// reset jump counter (faster to always set)
|
||
jumps = 0;
|
||
if (bestTarget < 0) {
|
||
printf("no best\n");
|
||
break;
|
||
}
|
||
// update path map
|
||
++usedpaths[std::min(lastPosition, bestTarget)][std::max(lastPosition, bestTarget)];
|
||
// add new stop
|
||
path.push_back(bestTarget);
|
||
// update used pins
|
||
++usedPins[bestTarget];
|
||
// progress report
|
||
if (iter % 100 == 0) {
|
||
printf("best %4i -> %4i(%4i, %4i) diff %9li (%12li) iter %5i path %i\n", lastPosition, bestTarget, nails[bestTarget] >> 16, nails[bestTarget] & 0xFFFF, compensatedBestDiff, totalDiff + realBestDiff, iter, usedpaths[std::min(lastPosition, bestTarget)][std::max(lastPosition, bestTarget)]);
|
||
}
|
||
// set new start position
|
||
lastPosition = bestTarget;
|
||
// update diff
|
||
totalDiff += realBestDiff;
|
||
// update current state from best map
|
||
memcpy(currentState, bestState, widthXheight * 2);
|
||
}
|
||
|
||
printf("size %li\n", path.size());
|
||
// we are done, create output svg
|
||
FILE* fh = fopen("map.svg", "wb");
|
||
fprintf(fh, "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n<svg xmlns=\"http://www.w3.org/2000/svg\" viewBox=\"0 0 %i %i\">\n<rect width=\"%i\" height=\"%i\" fill=\"#ffffff\" />\n<g style=\"fill:none;stroke:#000000;stroke-opacity:%.2f;stroke-width:1\">\n", realWidth, realHeight, realWidth, realHeight, lineColor / 255.0);
|
||
uint32_t counter = 0;
|
||
for (uint16_t i : path) {
|
||
if ((counter & 255) == 0) {
|
||
fprintf(fh, "<path d=\"M%i %i", nails[i] >> 16, nails[i] & 0xffff);
|
||
} else {
|
||
fprintf(fh, "L%i %i", nails[i] >> 16, nails[i] & 0xffff);
|
||
}
|
||
if ((counter & 255) == 255) {
|
||
fprintf(fh, "\" />\n");
|
||
}
|
||
++counter;
|
||
}
|
||
if ((counter & 255) != 0) {
|
||
fprintf(fh, "\" />\n");
|
||
}
|
||
gettimeofday(&tv2, NULL);
|
||
float timeNeeded = (tv2.tv_sec - tv1.tv_sec) + (tv2.tv_usec - tv1.tv_usec) / 1000000.0;
|
||
fprintf(fh, "</g>\n");
|
||
fprintf(fh, "<text x=\"30\" y=\"10\" style=\"font-weight:bold;font-size:60px;font-family:'DejaVu Serif'\"><tspan x=\"30\" y=\"70\">%s %s %i %i</tspan><tspan x=\"70\" y=\"150\"> %i %i %.2f %i</tspan><tspan x=\"30\" y=\"%i\">%i nails, %li paths, %.1f sec</tspan></text>", argv[0], imageName, resolutionX, resolutionY, atoi(argv[4]), maxIter, duplicateFactor, lineColor, realHeight - 30, numberOfNails, path.size(), timeNeeded);
|
||
fprintf(fh, "</svg>");
|
||
fclose(fh);
|
||
// cleanup
|
||
free(targetState);
|
||
free(bestState);
|
||
free(currentState);
|
||
path.clear();
|
||
linesFromSource.clear();
|
||
Magick::TerminateMagick();
|
||
}
|