// example6.c - Demonstrates how to miniz's PNG writer func | |
// Public domain, April 11 2012, Rich Geldreich, richgel99@gmail.com. See "unlicense" statement at the end of tinfl.c. | |
// Mandlebrot set code from http://rosettacode.org/wiki/Mandelbrot_set#C | |
// Must link this example against libm on Linux. | |
// Purposely disable a whole bunch of stuff this low-level example doesn't use. | |
#define MINIZ_NO_STDIO | |
#define MINIZ_NO_ARCHIVE_APIS | |
#define MINIZ_NO_TIME | |
#define MINIZ_NO_ZLIB_APIS | |
#include "miniz.c" | |
// Now include stdio.h because this test uses fopen(), etc. (but we still don't want miniz.c's stdio stuff, for testing). | |
#include <stdio.h> | |
#include <limits.h> | |
#include <math.h> | |
typedef unsigned char uint8; | |
typedef unsigned short uint16; | |
typedef unsigned int uint; | |
typedef struct | |
{ | |
uint8 r, g, b; | |
} rgb_t; | |
static void hsv_to_rgb(int hue, int min, int max, rgb_t *p) | |
{ | |
const int invert = 0; | |
const int saturation = 1; | |
const int color_rotate = 0; | |
if (min == max) max = min + 1; | |
if (invert) hue = max - (hue - min); | |
if (!saturation) { | |
p->r = p->g = p->b = 255 * (max - hue) / (max - min); | |
return; | |
} | |
double h = fmod(color_rotate + 1e-4 + 4.0 * (hue - min) / (max - min), 6); | |
double c = 255.0f * saturation; | |
double X = c * (1 - fabs(fmod(h, 2) - 1)); | |
p->r = p->g = p->b = 0; | |
switch((int)h) { | |
case 0: p->r = c; p->g = X; return; | |
case 1: p->r = X; p->g = c; return; | |
case 2: p->g = c; p->b = X; return; | |
case 3: p->g = X; p->b = c; return; | |
case 4: p->r = X; p->b = c; return; | |
default:p->r = c; p->b = X; | |
} | |
} | |
int main(int argc, char *argv[]) | |
{ | |
(void)argc, (void)argv; | |
// Image resolution | |
const int iXmax = 4096; | |
const int iYmax = 4096; | |
// Output filename | |
static const char *pFilename = "mandelbrot.png"; | |
int iX, iY; | |
const double CxMin = -2.5; | |
const double CxMax = 1.5; | |
const double CyMin = -2.0; | |
const double CyMax = 2.0; | |
double PixelWidth = (CxMax - CxMin) / iXmax; | |
double PixelHeight = (CyMax - CyMin) / iYmax; | |
// Z=Zx+Zy*i ; Z0 = 0 | |
double Zx, Zy; | |
double Zx2, Zy2; // Zx2=Zx*Zx; Zy2=Zy*Zy | |
int Iteration; | |
const int IterationMax = 200; | |
// bail-out value , radius of circle | |
const double EscapeRadius = 2; | |
double ER2=EscapeRadius * EscapeRadius; | |
uint8 *pImage = (uint8 *)malloc(iXmax * 3 * iYmax); | |
// world ( double) coordinate = parameter plane | |
double Cx,Cy; | |
int MinIter = 9999, MaxIter = 0; | |
for(iY = 0; iY < iYmax; iY++) | |
{ | |
Cy = CyMin + iY * PixelHeight; | |
if (fabs(Cy) < PixelHeight/2) | |
Cy = 0.0; // Main antenna | |
for(iX = 0; iX < iXmax; iX++) | |
{ | |
uint8 *color = pImage + (iX * 3) + (iY * iXmax * 3); | |
Cx = CxMin + iX * PixelWidth; | |
// initial value of orbit = critical point Z= 0 | |
Zx = 0.0; | |
Zy = 0.0; | |
Zx2 = Zx * Zx; | |
Zy2 = Zy * Zy; | |
for (Iteration=0;Iteration<IterationMax && ((Zx2+Zy2)<ER2);Iteration++) | |
{ | |
Zy = 2 * Zx * Zy + Cy; | |
Zx =Zx2 - Zy2 + Cx; | |
Zx2 = Zx * Zx; | |
Zy2 = Zy * Zy; | |
}; | |
color[0] = (uint8)Iteration; | |
color[1] = (uint8)Iteration >> 8; | |
color[2] = 0; | |
if (Iteration < MinIter) | |
MinIter = Iteration; | |
if (Iteration > MaxIter) | |
MaxIter = Iteration; | |
} | |
} | |
for(iY = 0; iY < iYmax; iY++) | |
{ | |
for(iX = 0; iX < iXmax; iX++) | |
{ | |
uint8 *color = (uint8 *)(pImage + (iX * 3) + (iY * iXmax * 3)); | |
uint Iterations = color[0] | (color[1] << 8U); | |
hsv_to_rgb(Iterations, MinIter, MaxIter, (rgb_t *)color); | |
} | |
} | |
// Now write the PNG image. | |
{ | |
size_t png_data_size = 0; | |
void *pPNG_data = tdefl_write_image_to_png_file_in_memory_ex(pImage, iXmax, iYmax, 3, &png_data_size, 6, MZ_FALSE); | |
if (!pPNG_data) | |
fprintf(stderr, "tdefl_write_image_to_png_file_in_memory_ex() failed!\n"); | |
else | |
{ | |
FILE *pFile = fopen(pFilename, "wb"); | |
fwrite(pPNG_data, 1, png_data_size, pFile); | |
fclose(pFile); | |
printf("Wrote %s\n", pFilename); | |
} | |
// mz_free() is by default just an alias to free() internally, but if you've overridden miniz's allocation funcs you'll probably need to call mz_free(). | |
mz_free(pPNG_data); | |
} | |
free(pImage); | |
return EXIT_SUCCESS; | |
} |