126 lines
3.2 KiB
C
126 lines
3.2 KiB
C
/*
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ChibiOS/GFX - Copyright (C) 2012
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Joel Bodenmann aka Tectu <joel@unormal.org>
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This file is part of ChibiOS/GFX.
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ChibiOS/GFX is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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ChibiOS/GFX is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include "ch.h"
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#include "hal.h"
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#include "gdisp.h"
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int count = 0;
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float mag = 1;
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float offsetx = -0.756423894274328;
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float offsety = 0.064179410646170;
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static float width, height;
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static uint16_t iterations, screen_off_x, screen_off_y;
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static uint16_t *FrameBuffer;
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static int generateColor(int count, int base) {
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int r,g,b;
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int d = (count % base) * 256 / base;
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int m = (int)(d / 42.667);
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switch(m) {
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case 0: r=0; g=6*d; b=255; break;
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case 1: r=0; g=255; b=255-6*(d-43); break;
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case 2: r=6*(d-86); g=255; b=0; break;
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case 3: r=255; g=255-6*(d-129); b=0; break;
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case 4: r=255; g=0; b=6*(d-171); break;
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case 5: r=255-6*(d-214); g=0; b=255; break;
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default: r=0; g=0; b=0; break;
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}
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return (((r >> 3) & 0x1f) << 11) | (((g >> 2) & 0x3f) << 5) | ((b >> 3) & 0x1f);
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}
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static void complex_mult(float ar,float ai,float br,float bi, float *cr,float *ci) {
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// C = A * B
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*cr = ar * br - ai * bi;
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*ci = ar * bi + ai * br;
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}
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static float complex_abs2(float r,float i) {
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float ar,ai;
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complex_mult(r,i,r,-i,&ar,&ai);
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return ar;
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}
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void mandelbrotInit(uint16_t mandel_width, uint16_t mandel_height, uint16_t mandel_iterations) {
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const char *msg = "ChibiOS/GFX";
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width = (float)mandel_width;
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height = (float)mandel_height;
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iterations = mandel_iterations;
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FrameBuffer = chHeapAlloc(NULL, width * height * sizeof(uint16_t));
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if(FrameBuffer == NULL)
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return;
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screen_off_x = (gdispGetWidth() - width) / 2;
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screen_off_y = (gdispGetHeight() - height) / 2;
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gdispClear(Black);
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gdispDrawString((gdispGetWidth() - gdispGetStringWidth(msg, &fontUI2Double)) / 2, 5, "ChibiOS/GFX", &fontUI2Double, White);
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while(TRUE) {
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mandelbrotLoop();
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}
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}
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void mandelbrotLoop() {
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int x, y;
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int pos = 0;
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for(y = 0; y < height; y++) {
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for(x = 0; x < width; x++) {
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float cr = (x - width/2.) / (width/2.) / mag + offsetx;
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float ci = (y - width/2.) / (width/2.) / mag + offsety;
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float zr = 0;
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float zi = 0;
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int t;
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for(t = 0; t < iterations; t++) {
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if(complex_abs2(zr,zi) > 4)
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break;
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complex_mult(zr,zi,zr,zi,&zr,&zi);
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zr += cr;
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zi += ci;
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}
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FrameBuffer[pos++] = generateColor(t, 64);
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}
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}
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gdispBlitArea(screen_off_x, screen_off_y, width, height, FrameBuffer);
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// magnification
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mag = mag * 1.2;
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// panning
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//offsety += 0.001;
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//offsetx += 0.0016;
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if(count++ > 80) {
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offsetx = -0.756423894274328;
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offsety = 0.064179410646170;
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mag = 1;
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count = 0;
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}
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}
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