Add libpng screenshot support.

Makefile

@@ -157,6 +157,11 @@ ifeq ($(HAVE_SDL_IMAGE), 1)
    DEFINES += $(SDL_IMAGE_CFLAGS)
 endif
 
+ifeq ($(HAVE_LIBPNG), 1)
+   LIBS += $(LIBPNG_LIBS)
+   DEFINES += $(LIBPNG_CFLAGS)
+endif
+
 ifeq ($(HAVE_FFMPEG), 1)
    OBJ += record/ffemu.o
    LIBS += $(AVCODEC_LIBS) $(AVFORMAT_LIBS) $(AVUTIL_LIBS) $(SWSCALE_LIBS)

config.features.h

@@ -110,6 +110,12 @@ static const bool _sdl_image_supp = true;
 static const bool _sdl_image_supp = false;
 #endif
 
+#ifdef HAVE_LIBPNG
+static const bool _libpng_supp = true;
+#else
+static const bool _libpng_supp = false;
+#endif
+
 #ifdef HAVE_FBO
 static const bool _fbo_supp = true;
 #else

qb/config.libs.sh

@@ -81,6 +81,7 @@ fi
 
 check_pkgconf XML libxml-2.0
 check_pkgconf SDL_IMAGE SDL_image
+check_pkgconf LIBPNG libpng
 
 if [ "$HAVE_THREADS" != 'no' ]; then
    if [ "$HAVE_FFMPEG" != 'no' ]; then
@@ -128,6 +129,6 @@ check_pkgconf PYTHON python3
 add_define_make OS "$OS"
 
 # Creates config.mk and config.h.
-VARS="ALSA OSS OSS_BSD OSS_LIB AL RSOUND ROAR JACK COREAUDIO PULSE SDL OPENGL DYLIB GETOPT_LONG THREADS CG XML SDL_IMAGE DYNAMIC FFMPEG AVCODEC AVFORMAT AVUTIL SWSCALE CONFIGFILE FREETYPE XVIDEO X11 XEXT NETPLAY NETWORK_CMD SOCKET_LEGACY FBO STRL PYTHON FFMPEG_ALLOC_CONTEXT3 FFMPEG_AVCODEC_OPEN2 FFMPEG_AVIO_OPEN FFMPEG_AVFORMAT_WRITE_HEADER FFMPEG_AVFORMAT_NEW_STREAM FFMPEG_AVCODEC_ENCODE_AUDIO2 FFMPEG_AVCODEC_ENCODE_VIDEO2 X264RGB SINC BSV_MOVIE"
+VARS="ALSA OSS OSS_BSD OSS_LIB AL RSOUND ROAR JACK COREAUDIO PULSE SDL OPENGL DYLIB GETOPT_LONG THREADS CG XML SDL_IMAGE LIBPNG DYNAMIC FFMPEG AVCODEC AVFORMAT AVUTIL SWSCALE CONFIGFILE FREETYPE XVIDEO X11 XEXT NETPLAY NETWORK_CMD SOCKET_LEGACY FBO STRL PYTHON FFMPEG_ALLOC_CONTEXT3 FFMPEG_AVCODEC_OPEN2 FFMPEG_AVIO_OPEN FFMPEG_AVFORMAT_WRITE_HEADER FFMPEG_AVFORMAT_NEW_STREAM FFMPEG_AVCODEC_ENCODE_AUDIO2 FFMPEG_AVCODEC_ENCODE_VIDEO2 X264RGB SINC BSV_MOVIE"
 create_config_make config.mk $VARS
-create_config_header config.h $VARS
+create_config_header config.h $VARS

qb/config.params.sh

@@ -21,6 +21,7 @@ HAVE_PULSE=auto         # Enable PulseAudio support
 HAVE_FREETYPE=auto      # Enable FreeType support
 HAVE_XVIDEO=auto        # Enable XVideo support
 HAVE_SDL_IMAGE=auto     # Enable SDL_image support
+HAVE_LIBPNG=auto        # Enable libpng support
 HAVE_PYTHON=auto        # Enable Python 3 support for shaders
 HAVE_SINC=yes           # Disable SINC resampler
 HAVE_BSV_MOVIE=yes      # Disable BSV movie support

retroarch.c

@@ -495,6 +495,7 @@ static void print_features(void)
    _PSUPP(cg, "Cg", "Cg pixel shaders");
    _PSUPP(xml, "XML", "bSNES XML pixel shaders");
    _PSUPP(sdl_image, "SDL_image", "SDL_image image loading");
+   _PSUPP(libpng, "libpng", "libpng screenshot support");
    _PSUPP(fbo, "FBO", "OpenGL render-to-texture (multi-pass shaders)");
    _PSUPP(dynamic, "Dynamic", "Dynamic run-time loading of libretro library");
    _PSUPP(ffmpeg, "FFmpeg", "On-the-fly recording of gameplay with libavcodec");

screenshot.c

@@ -22,9 +22,80 @@
 #include <string.h>
 #include "general.h"
 
-// Simple 24bpp .BMP writer.
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
 
-static void write_header(FILE *file, unsigned width, unsigned height)
+#ifdef HAVE_LIBPNG
+#include <png.h>
+#endif
+
+#ifdef HAVE_LIBPNG
+static png_structp png_ptr;
+static png_infop png_info_ptr;
+
+static void destroy_png(void)
+{
+   if (png_ptr)
+      png_destroy_write_struct(&png_ptr, &png_info_ptr);
+}
+
+static bool write_header_png(FILE *file, unsigned width, unsigned height)
+{
+   png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+   if (!png_ptr)
+      return false;
+
+   if (setjmp(png_jmpbuf(png_ptr)))
+      goto error;
+
+   png_info_ptr = png_create_info_struct(png_ptr);
+   if (!png_info_ptr)
+      goto error;
+
+   png_init_io(png_ptr, file);
+
+   png_set_IHDR(png_ptr, png_info_ptr, width, height, 8,
+         PNG_COLOR_TYPE_RGB, PNG_INTERLACE_NONE,
+         PNG_COMPRESSION_TYPE_DEFAULT, PNG_FILTER_TYPE_DEFAULT);
+
+   png_write_info(png_ptr, png_info_ptr);
+   png_set_compression_level(png_ptr, 9);
+
+   return true;
+
+error:
+   destroy_png();
+   return false;
+}
+
+static void dump_lines_png(uint8_t **lines, int height)
+{
+   if (setjmp(png_jmpbuf(png_ptr)))
+   {
+      RARCH_ERR("PNG: dump_lines_png() failed!\n");
+      goto end;
+   }
+
+   // PNG is top-down, BMP is bottom-up.
+   for (int i = 0, j = height - 1; i < j; i++, j--)
+   {
+      uint8_t *tmp = lines[i];
+      lines[i] = lines[j];
+      lines[j] = tmp;
+   }
+
+   png_set_rows(png_ptr, png_info_ptr, lines);
+   png_write_png(png_ptr, png_info_ptr, PNG_TRANSFORM_BGR, NULL);
+   png_write_end(png_ptr, NULL);
+
+end:
+   destroy_png();
+}
+
+#else
+
+static bool write_header_bmp(FILE *file, unsigned width, unsigned height)
 {
    unsigned line_size = (width * 3 + 3) & ~3;
    unsigned size = line_size * height + 54;
@@ -49,9 +120,17 @@ static void write_header(FILE *file, unsigned width, unsigned height)
       0, 0, 0, 0
    };
 
-   fwrite(header, 1, sizeof(header), file);
+   return fwrite(header, 1, sizeof(header), file) == sizeof(header);
 }
 
+static void dump_lines_file(FILE *file, uint8_t **lines, size_t line_size, unsigned height)
+{
+   for (unsigned i = 0; i < height; i++)
+      fwrite(lines[i], 1, line_size, file);
+}
+
+#endif
+
 static void dump_line_bgr(uint8_t *line, const uint8_t *src, unsigned width)
 {
    memcpy(line, src, width * 3);
@@ -78,31 +157,42 @@ static void dump_content(FILE *file, const void *frame,
    const uint16_t *frame16   = (const uint16_t*)frame;
 
    if (!bgr24)
-      pitch /= 2;
+      pitch /= sizeof(uint16_t);
 
-   unsigned line_size = (width * 3 + 3) & ~3;
-   uint8_t *line = (uint8_t*)calloc(1, line_size);
-   if (!line)
+   uint8_t **lines = (uint8_t**)calloc(height, sizeof(uint8_t*));
+   if (!lines)
       return;
 
+   size_t line_size = (width * 3 + 3) & ~3;
+
+   for (int i = 0; i < height; i++)
+   {
+      lines[i] = (uint8_t*)calloc(1, line_size);
+      if (!lines[i])
+         goto end;
+   }
+
    if (bgr24) // BGR24 byte order. Can directly copy.
    {
       for (int j = 0; j < height; j++, frame_bgr += pitch)
-      {
-         dump_line_bgr(line, frame_bgr, width);
-         fwrite(line, 1, line_size, file);
-      }
+         dump_line_bgr(lines[j], frame_bgr, width);
    }
    else // ARGB1555
    {
       for (int j = 0; j < height; j++, frame16 += pitch)
-      {
-         dump_line_16(line, frame16, width);
-         fwrite(line, 1, line_size, file);
-      }
+         dump_line_16(lines[j], frame16, width);
    }
 
-   free(line);
+#ifdef HAVE_LIBPNG
+   dump_lines_png(lines, height);
+#else
+   dump_lines_file(file, lines, line_size, height);
+#endif
+
+end:
+   for (int i = 0; i < height; i++)
+      free(lines[i]);
+   free(lines);
 }
 
 bool screenshot_dump(const char *folder, const void *frame,
@@ -111,8 +201,14 @@ bool screenshot_dump(const char *folder, const void *frame,
    time_t cur_time;
    time(&cur_time);
 
+#ifdef HAVE_LIBPNG
+#define IMG_EXT "png"
+#else
+#define IMG_EXT "bmp"
+#endif
+
    char timefmt[128];
-   strftime(timefmt, sizeof(timefmt), "RetroArch-%m%d-%H%M%S.bmp", localtime(&cur_time));
+   strftime(timefmt, sizeof(timefmt), "RetroArch-%m%d-%H%M%S." IMG_EXT, localtime(&cur_time));
 
    char filename[PATH_MAX];
    snprintf(filename, sizeof(filename), "%s/%s", folder, timefmt);
@@ -124,11 +220,18 @@ bool screenshot_dump(const char *folder, const void *frame,
       return false;
    }
 
-   write_header(file, width, height);
-   dump_content(file, frame, width, height, pitch, bgr24);
+#ifdef HAVE_LIBPNG
+   bool ret = write_header_png(file, width, height);
+#else
+   bool ret = write_header_bmp(file, width, height);
+#endif
+
+   if (ret)
+      dump_content(file, frame, width, height, pitch, bgr24);
+   else
+      RARCH_ERR("Failed to write image header.\n");
 
    fclose(file);
-
-   return true;
+   return ret;
 }