Initial checkin of v115 - 1 important bugfix, few minor bugfixes, cmake support, merged a bunch of fixes from other folks, added improved PNG writer, etc.

example6.c

@@ -0,0 +1,163 @@
+// 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;
+}