159 lines
3.7 KiB
C
159 lines
3.7 KiB
C
#include <stdio.h>
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#include <gtk/gtk.h>
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#include <math.h>
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#include <threads.h>
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struct canvas_buffer {
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unsigned int *mandelbrot_buffer;
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unsigned int iterations;
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unsigned int height;
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unsigned int width;
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double center_x;
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double center_y;
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double x_span;
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double y_span;
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};
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static gboolean on_main_window_close(GtkWidget *window, gpointer data)
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{
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gtk_main_quit();
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return FALSE;
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}
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static gboolean drawing_callback(GtkWidget *widget, cairo_t *cr, gpointer data)
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{
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struct canvas_buffer *buff = (struct canvas_buffer *)data;
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int width;
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int height;
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GtkStyleContext *style_context;
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int x, y;
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double color_scale;
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style_context = gtk_widget_get_style_context(widget);
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width = gtk_widget_get_allocated_width(widget);
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height = gtk_widget_get_allocated_height(widget);
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cairo_save(cr);
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/* Drawing code start */
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cairo_scale(cr, 1, -1);
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cairo_translate(cr, (double)width/2.0, -(double)height/2.0);
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for (x = 0; x < buff->width; x++) {
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for (y = 0; y < buff->height; y++) {
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cairo_rectangle(cr,
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((double)x - (double)(buff->width - 1) / 2),
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((double)y - (double)(buff->height - 1) / 2),
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1,
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1);
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if (buff->mandelbrot_buffer[y * buff->width + x] == buff->iterations) {
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cairo_set_source_rgb (cr, 0, 0, 0);
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} else {
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color_scale = (double)buff->mandelbrot_buffer[y * buff->width + x] / buff->iterations;
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cairo_set_source_rgb (cr, (sqrt(1-color_scale)), (color_scale*color_scale), color_scale);
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}
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cairo_fill(cr);
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}
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}
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/* Drawing code end */
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cairo_restore(cr);
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return FALSE;
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}
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static void calculate_mandelbrot(struct canvas_buffer *buff)
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{
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double val_per_x_pixel;
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double val_per_y_pixel;
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unsigned int i;
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unsigned int pixel_x;
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unsigned int pixel_y;
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double point_real, point_imag;
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double z_real, z_imag;
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double z2_real, z2_imag;
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if (!buff)
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return;
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/* Setup the calculation data */
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val_per_x_pixel = (buff->x_span) / (buff->width - 1);
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val_per_y_pixel = (buff->y_span) / (buff->height - 1);
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for (pixel_y = 0; pixel_y < buff->height; pixel_y++) {
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for (pixel_x = 0; pixel_x < buff->width; pixel_x++) {
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point_real = (((double)pixel_x - (double)(buff->width - 1) / 2)) * val_per_x_pixel + buff->center_x;
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point_imag = (((double)pixel_y - (double)(buff->height - 1) / 2)) * val_per_y_pixel + buff->center_y;
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z_real = 0.0;
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z_imag = 0.0;
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/* Check for convergence */
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for (i = 0; i < buff->iterations; i++) {
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z2_real = z_real * z_real - z_imag * z_imag;
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z2_imag = 2.0 * z_real * z_imag;
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z_real = z2_real + point_real;
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z_imag = z2_imag + point_imag;
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if ((z_real * z_real + z_imag * z_imag) >= 4.0)
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break;
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}
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buff->mandelbrot_buffer[pixel_y * buff->width + pixel_x] = i;
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}
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}
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}
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int f(void * a)
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{
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return 1;
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}
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int main(int argc, char **argv)
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{
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GtkDrawingArea *drawing_area;
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GtkWindow *window;
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GtkBuilder *builder;
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static struct canvas_buffer mandelbrot_buff;
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gtk_init(&argc, &argv);
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builder = gtk_builder_new_from_resource("/main.glade");
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drawing_area = GTK_DRAWING_AREA(gtk_builder_get_object(builder, "drawing-area"));
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window = GTK_WINDOW(gtk_builder_get_object(builder, "main-window"));
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g_signal_connect(window, "delete-event", G_CALLBACK(on_main_window_close), NULL);
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g_signal_connect(G_OBJECT(drawing_area),
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"draw", G_CALLBACK(drawing_callback), (gpointer)&mandelbrot_buff);
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g_object_unref(builder);
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thrd_t t;
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thrd_create(&t, f, NULL);
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mandelbrot_buff.x_span = 2.8;
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mandelbrot_buff.y_span = 2.25;
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mandelbrot_buff.center_x = -0.5;
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mandelbrot_buff.center_y = 0.0;
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mandelbrot_buff.width = 1900;
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mandelbrot_buff.height = 1000;
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mandelbrot_buff.iterations = 300;
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mandelbrot_buff.mandelbrot_buffer = (unsigned int *)malloc(sizeof(unsigned int) * mandelbrot_buff.height * mandelbrot_buff.width);
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calculate_mandelbrot(&mandelbrot_buff);
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gtk_main();
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return 0;
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}
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