make auto_choose_color static since it's only internal

3 files changed, 13 insertions, 3 deletions

diff --git a/lodepng.cpp b/lodepng.cpp
index 74c7fde..29f50c5 100644
--- a/lodepng.cpp
+++ b/lodepng.cpp
@@ -3829,9 +3829,16 @@ static void lodepng_color_stats_add(LodePNGColorStats* stats,
 }
 #endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/
 
-unsigned auto_choose_color(LodePNGColorMode* mode_out,
-                           const LodePNGColorMode* mode_in,
-                           const LodePNGColorStats* stats) {
+/*Computes a minimal PNG color model that can contain all colors as indicated by the stats.
+The stats should be computed with lodepng_compute_color_stats.
+mode_in is raw color profile of the image the stats were computed on, to copy palette order from when relevant.
+Minimal PNG color model means the color type and bit depth that gives smallest amount of bits in the output image,
+e.g. gray if only grayscale pixels, palette if less than 256 colors, color key if only single transparent color, ...
+This is used if auto_convert is enabled (it is by default).
+*/
+static unsigned auto_choose_color(LodePNGColorMode* mode_out,
+                                  const LodePNGColorMode* mode_in,
+                                  const LodePNGColorStats* stats) {
   unsigned error = 0;
   unsigned palettebits;
   size_t i, n;
diff --git a/lodepng.h b/lodepng.h
index 1a473e7..c0fa407 100644
--- a/lodepng.h
+++ b/lodepng.h
@@ -697,6 +697,7 @@ void lodepng_color_stats_init(LodePNGColorStats* stats);
 void lodepng_compute_color_stats(LodePNGColorStats* stats,
                                  const unsigned char* image, unsigned w, unsigned h,
                                  const LodePNGColorMode* mode_in);
+
 /*Settings for the encoder.*/
 typedef struct LodePNGEncoderSettings {
   LodePNGCompressSettings zlibsettings; /*settings for the zlib encoder, such as window size, ...*/
diff --git a/lodepng_unittest.cpp b/lodepng_unittest.cpp
index ebc2d1a..372d104 100644
--- a/lodepng_unittest.cpp
+++ b/lodepng_unittest.cpp
@@ -75,6 +75,8 @@ g++ lodepng.cpp -W -Wall -ansi -pedantic -O3 -c -DLODEPNG_NO_COMPILE_ZLIB -DLODE
 g++ lodepng.cpp -W -Wall -ansi -pedantic -O3 -c -DLODEPNG_NO_COMPILE_ZLIB -DLODEPNG_NO_COMPILE_ENCODER
 g++ lodepng.cpp -W -Wall -ansi -pedantic -O3 -c -DLODEPNG_NO_COMPILE_PNG -DLODEPNG_NO_COMPILE_DECODER
 g++ lodepng.cpp -W -Wall -ansi -pedantic -O3 -c -DLODEPNG_NO_COMPILE_PNG -DLODEPNG_NO_COMPILE_ENCODER
+g++ lodepng.cpp -W -Wall -ansi -pedantic -O3 -c -DLODEPNG_NO_COMPILE_DECODER -DLODEPNG_NO_COMPILE_ANCILLARY_CHUNKS -DLODEPNG_NO_COMPILE_ERROR_TEXT -DLODEPNG_NO_COMPILE_DISK
+g++ lodepng.cpp -W -Wall -ansi -pedantic -O3 -c -DLODEPNG_NO_COMPILE_ENCODER -DLODEPNG_NO_COMPILE_ANCILLARY_CHUNKS -DLODEPNG_NO_COMPILE_ERROR_TEXT -DLODEPNG_NO_COMPILE_DISK
 rm *.o
 
 *) analyze with clang: