54 lines
2.5 KiB
C
54 lines
2.5 KiB
C
#include "tricorn_V1.h"
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#include "color_table.h"
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#include "converge_helper.h"
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/**
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* @brief Generates a Tricorn fractal image using an optimized scalar implementation.
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* @param start The starting complex coordinate (bottom-left or top-left depending on height sign).
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* @param width The width of the target image in pixels.
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* @param height The height of the target image. A negative height reverses the Y-axis calculation.
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* @param res The step size (resolution) per pixel in the complex plane.
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* @param n The maximum number of mathematical iterations per pixel.
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* @param color If true, generates a 24-bit RGB image. If false, writes a grayscale image.
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* @param img Pointer to the pre-allocated memory buffer where the bitmap data will be stored.
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*/
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void tricorn_V1(float complex start, size_t width, ssize_t height, float res, unsigned n, _Bool color, unsigned char* img){
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int bytesPerColor = color ? 3 : 1;
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// Absolute height for iteration purposes
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ssize_t actual_height = height > 0 ? height : (ssize_t)(-height);
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// Depending on the sign of height we generate the image top-down or bottom up
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// As we iterate from the top always, if it is negative we would have to start at the end of the imaginary part and go in the oposite direction when generating
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ssize_t imag_direction = height < 0 ? -1 : 1;
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float c_start_real = creal(start);
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float c_start_imag = height > 0 ? cimag(start) : cimag(start) + ((actual_height-1) * res);
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float vertical_step = imag_direction * res;
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size_t position = 0; // Start value for the position in the image buffer. Will be accumulated later
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float c_imag = c_start_imag; // Start value for the imaginary part, which will be accumulated
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for(ssize_t y = 0; y < actual_height; y++){
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float c_real = c_start_real;
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for(size_t x = 0; x < width; x++){
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unsigned value = converge(c_real,c_imag,n);
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if(!color){ // Grayscale colors as specified by the assignment r = g = b
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img[position] = value;
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}
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else{ // Temporary colors with random multipliers
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img[position] = color_lookup_table[value][0];
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img[position + 1] = color_lookup_table[value][1];
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img[position + 2] = color_lookup_table[value][2];
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}
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position += bytesPerColor; // Caculate position for next pixel
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c_real += res; // Calculate real part for next pixel
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}
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c_imag += vertical_step; // For reach row calculate the next value for the imaginary part by accumulation
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}
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}
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