mandelbrot: make bailout a variable

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2011-11-11 23:21:42 +01:00
parent 847e61de4a
commit 75e309160b

View File

@ -38,6 +38,7 @@ typedef struct {
double start_x;
double start_y;
double start_scale;
double bailout;
} MBContext;
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
@ -52,6 +53,7 @@ static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
mb->start_x=-2.0;
mb->start_y=-1.5;
mb->start_scale=3.0;
mb->bailout=100;
if (args)
sscanf(args, "%127[^:]:%127[^:]:%d,%lf:%lf:%lf", frame_size, frame_rate, &mb->maxiter, &mb->start_x, &mb->start_y, &mb->start_scale);
@ -116,13 +118,12 @@ static void draw_mandelbrot(AVFilterContext *ctx, uint32_t *color, int linesize,
double ci=mb->start_y+mb->start_scale*y;
double zr=cr;
double zi=ci;
const double B=100;
uint32_t c=0;
for(i=0; i<256; i++){
double t;
if(zr*zr + zi*zi > B){
zr= i + (log(log(B)) - log(log(sqrt(zr*zr + zi*zi))))/log(2);
if(zr*zr + zi*zi > mb->bailout){
zr= i + (log(log(mb->bailout)) - log(log(sqrt(zr*zr + zi*zi))))/log(2); break;
c= lrintf((sin(zr)+1)*127) + lrintf((sin(zr/1.234)+1)*127)*256*256 + lrintf((sin(zr/100)+1)*127)*256;
break;
}