#include "tricorn_V3.h"

static const float convergenceLimit = 2.0f; // Mandelbrot set limit
static unsigned converge(float complex position,unsigned n);

/**
 * @brief Generates a Tricorn fractal image using the standard, unoptimized scalar implementation for benchmarking comparison (Version 2).
 * @param start The starting complex coordinate (bottom-left or top-left depending on height sign).
 * @param width The width of the target image in pixels.
 * @param height The height of the target image. A negative height reverses the Y-axis calculation.
 * @param res The step size (resolution) per pixel in the complex plane.
 * @param n The maximum number of mathematical iterations per pixel.
 * @param color If true, generates a 24-bit RGB image. If false, writes a grayscale image.
 * @param img Pointer to the pre-allocated memory buffer where the bitmap data will be stored.
 */
void tricorn_V3(float complex start, size_t width, ssize_t height, float res, unsigned n, _Bool color, unsigned char* img){
    
    float imag_direction = height < 0 ? -1.0f : 1.0f;
    unsigned bytesPerColor = color ? 3 : 1;
    height = height < 0? -height : height;

    // Simple iteration over every pixel in the picture
    for(size_t i = 0; i < width; i++){
        for(ssize_t j = 0; j < height; j++){

            unsigned value = converge(start + (i*res - I* imag_direction*j*res),n);

            // Pixel value position in the output array
            size_t position = (j*width +i) * bytesPerColor;


            if(!color){ // Grayscale colors as specified by the assignment r = g = b
                img[position] =  value;
            }
            else{ // Temporary colors with random multipliers
                img[position] = ((value*3) % 255);
                img[position + 1] = ((value*2) % 255) ;
                img[position + 2] = ((value*5) % 255);
            }

        }
    }
}

// Iterative application of the equation given by the assignment
static unsigned converge(float complex position,unsigned n){

    complex float result  = 0;
    for(unsigned i = 0; i < n; i++){
         // Detection of unbounded behaviour
        // If the magnitude of the result vector is greater than the convergence limit, we know that the function will grow unbounded
        // Current convergence limit taken from mandelbrot set
        if(sqrtf(powf (crealf(result),2)+powf(cimagf(result),2)) > convergenceLimit)
            return 255-4*(i % 64);

        // Application of the given complex equation with m = 2
        result = cpowf(conjf(result),2) + position;
       
    }
    return 0;
}