# HG changeset patch
# User John Tsiombikas <nuclear@member.fsf.org>
# Date 1394170968 -7200
# Node ID e9ae6289e14fb1b061398d327f6d3636a7e4f99e

initial commit

diff -r 000000000000 -r e9ae6289e14f Makefile
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/Makefile	Fri Mar 07 07:42:48 2014 +0200
@@ -0,0 +1,13 @@
+src = $(wildcard src/*.c)
+obj = $(src:.c=.o)
+bin = mbrot
+
+CFLAGS = -pedantic -Wall -g `pkg-config --cflags sdl`
+LDFLAGS = `pkg-config --libs sdl`
+
+$(bin): $(obj)
+	$(CC) -o $@ $(obj) $(LDFLAGS)
+
+.PHONY: clean
+clean:
+	rm -f $(obj) $(bin)
diff -r 000000000000 -r e9ae6289e14f src/mbrot-mt.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/mbrot-mt.c	Fri Mar 07 07:42:48 2014 +0200
@@ -0,0 +1,159 @@
+#include <stdio.h>
+#include <complex.h>
+#include <SDL/SDL.h>
+
+void display(void);
+int mandelbrot(float x, float y, int max_iter, int *iter);
+int handle_event(SDL_Event *ev);
+
+static SDL_Surface *fbsurf;
+static int win_width, win_height;
+static float win_aspect;
+static float xoffs, yoffs, zoom = 1.0;
+static int max_iter = 64;
+
+int main(void)
+{
+	win_width = 800;
+	win_height = 600;
+	win_aspect = (float)win_width / (float)win_height;
+
+	SDL_Init(SDL_INIT_VIDEO | SDL_INIT_TIMER);
+	if(!(fbsurf = SDL_SetVideoMode(win_width, win_height, 32, SDL_SWSURFACE | SDL_RESIZABLE))) {
+		fprintf(stderr, "failed to create framebuffer\n");
+		return 1;
+	}
+
+	SDL_WM_SetCaption("Mandelbrot", 0);
+
+	for(;;) {
+		SDL_Event ev;
+
+		while(SDL_PollEvent(&ev)) {
+			if(handle_event(&ev) == -1) {
+				goto done;
+			}
+		}
+
+		display();
+	}
+
+done:
+	SDL_Quit();
+	return 0;
+}
+
+void display(void)
+{
+	unsigned char *fbuf, *pixptr;
+	int i, j, xsz, ysz;
+
+	if(SDL_MUSTLOCK(fbsurf)) {
+		SDL_LockSurface(fbsurf);
+	}
+	fbuf = fbsurf->pixels;
+	xsz = fbsurf->w;
+	ysz = fbsurf->h;
+
+	pixptr = fbuf;
+	for(i=0; i<ysz; i++) {
+		float y = 2.0 * (float)i / (float)ysz - 1.0;
+		for(j=0; j<xsz; j++) {
+			float x = (2.0 * (float)j / (float)xsz - 1.0) * win_aspect;
+
+			int iter, r, g, b;
+			int inset = mandelbrot((x - xoffs) * zoom, (y - yoffs) * zoom, max_iter, &iter);
+			if(!inset) {
+				r = iter * 256 / max_iter;
+				g = 0;
+				b = 0;
+			} else {
+				r = g = b = 0;
+			}
+
+			pixptr[0] = b;
+			pixptr[1] = g;
+			pixptr[2] = r;
+			pixptr[3] = 255;
+			pixptr += 4;
+		}
+	}
+
+	if(SDL_MUSTLOCK(fbsurf)) {
+		SDL_UnlockSurface(fbsurf);
+	}
+	SDL_Flip(fbsurf);
+}
+
+int mandelbrot(float x, float y, int max_iter, int *iter)
+{
+	int i;
+	complex float c = x + y * I;
+	complex float z = c;
+
+	for(i=0; i<max_iter; i++) {
+		float re = creal(z);
+		float im = cimag(z);
+		if(re * re + im * im > 4) {
+			if(iter) *iter = i;
+			return 0;
+		}
+
+		z = z * z + c;
+	}
+
+	return 1;
+}
+
+int handle_event(SDL_Event *ev)
+{
+	static int prev_x, prev_y;
+	static int bnstate[32];
+
+	switch(ev->type) {
+	case SDL_KEYDOWN:
+		if(ev->key.keysym.sym == SDLK_ESCAPE) {
+			return -1;
+		}
+
+	case SDL_MOUSEBUTTONDOWN:
+		prev_x = ev->button.x;
+		prev_y = ev->button.y;
+		bnstate[ev->button.button - SDL_BUTTON_LEFT] = 1;
+		break;
+
+	case SDL_MOUSEBUTTONUP:
+		bnstate[ev->button.button - SDL_BUTTON_LEFT] = 0;
+		break;
+
+	case SDL_MOUSEMOTION:
+		{
+			int dx = ev->button.x - prev_x;
+			int dy = ev->button.y - prev_y;
+			prev_x = ev->button.x;
+			prev_y = ev->button.y;
+
+			if(!dx && !dy) break;
+
+			if(bnstate[0]) {
+				xoffs += win_aspect * 2.0 * (float)dx / (float)win_width;
+				yoffs += 2.0 * (float)dy / (float)win_height;
+			}
+			if(bnstate[2]) {
+				zoom += (float)dy / (float)win_height;
+				if(zoom < 1e-6) zoom = 1e-6;
+			}
+		}
+		break;
+
+	case SDL_VIDEORESIZE:
+		win_width = ev->resize.w;
+		win_height = ev->resize.h;
+		win_aspect = (float)win_width / (float)win_height;
+		break;
+
+	default:
+		break;
+	}
+	return 0;
+}