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#include "ch.h"
#include "hal.h"
#include "gdisp.h"
int count = 0;
float mag = 1;
float offsetx = -0.756423894274328;
float offsety = 0.064179410646170;
static float width, height;
static uint16_t iterations, screen_off_x, screen_off_y;
static uint16_t *FrameBuffer;
static int generateColor(int count, int base) {
int r,g,b;
int d = (count % base) * 256 / base;
int m = (int)(d / 42.667);
switch(m) {
case 0: r=0; g=6*d; b=255; break;
case 1: r=0; g=255; b=255-6*(d-43); break;
case 2: r=6*(d-86); g=255; b=0; break;
case 3: r=255; g=255-6*(d-129); b=0; break;
case 4: r=255; g=0; b=6*(d-171); break;
case 5: r=255-6*(d-214); g=0; b=255; break;
default: r=0; g=0; b=0; break;
}
return (((r >> 3) & 0x1f) << 11) | (((g >> 2) & 0x3f) << 5) | ((b >> 3) & 0x1f);
}
static void complex_mult(float ar,float ai,float br,float bi, float *cr,float *ci) {
// C = A * B
*cr = ar * br - ai * bi;
*ci = ar * bi + ai * br;
}
static float complex_abs2(float r,float i) {
float ar,ai;
complex_mult(r,i,r,-i,&ar,&ai);
return ar;
}
void mandelbrotInit(uint16_t mandel_width, uint16_t mandel_height, uint16_t mandel_iterations) {
const char *msg = "ChibiOS/GFX";
width = (float)mandel_width;
height = (float)mandel_height;
iterations = mandel_iterations;
FrameBuffer = chHeapAlloc(NULL, width * height * sizeof(uint16_t));
if(FrameBuffer == NULL)
return;
screen_off_x = (gdispGetWidth() - width) / 2;
screen_off_y = (gdispGetHeight() - height) / 2;
gdispClear(Black);
gdispDrawString((gdispGetWidth() - gdispGetStringWidth(msg, &fontUI2Double)) / 2, 5, "ChibiOS/GFX", &fontUI2Double, White);
while(TRUE) {
mandelbrotLoop();
}
}
void mandelbrotLoop() {
int x, y;
int pos = 0;
for(y = 0; y < height; y++) {
for(x = 0; x < width; x++) {
float cr = (x - width/2.) / (width/2.) / mag + offsetx;
float ci = (y - width/2.) / (width/2.) / mag + offsety;
float zr = 0;
float zi = 0;
int t;
for(t = 0; t < iterations; t++) {
if(complex_abs2(zr,zi) > 4)
break;
complex_mult(zr,zi,zr,zi,&zr,&zi);
zr += cr;
zi += ci;
}
FrameBuffer[pos++] = generateColor(t, 64);
}
}
gdispBlitArea(screen_off_x, screen_off_y, width, height, FrameBuffer);
// magnification
mag = mag * 1.2;
// panning
//offsety += 0.001;
//offsetx += 0.0016;
if(count++ > 500) {
offsetx = -0.756423894274328;
offsety = 0.064179410646170;
mag = 1;
count = 0;
}
}
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