[freetype2-demos] master c6cf8eb: [ftgrid, ftview, ftstring] Implement PNG printing.

[Alexei Podtelezhnikov]

branch: master
commit c6cf8eb2887c3a7ab47bdb5fe2563b335514c396
Author: Alexei Podtelezhnikov <address@hidden>
Commit: Alexei Podtelezhnikov <address@hidden>

    [ftgrid,ftview,ftstring] Implement PNG printing.
    
    * src/ftcommon.[hc] (FT_Display_Print): New function.
    * src/{ftgrid,ftview,ftstring}.c (Process_Event): New event.
    
    * Makefile: Compile with appropriate <ftoption.h> so that
    FT_CONFIG_OPTION_USE_PNG status is inherited from the library build
    and based on the libPNG avalability.
---
 ChangeLog      |  11 ++++++
 Makefile       |   1 +
 src/ftcommon.c | 117 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 src/ftcommon.h |   6 +++
 src/ftgrid.c   |  11 ++++++
 src/ftstring.c |  13 +++++++
 src/ftview.c   |  13 ++++++-
 7 files changed, 171 insertions(+), 1 deletion(-)

diff --git a/ChangeLog b/ChangeLog
index 3f55f0a..2bd5741 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2019-06-03  Alexei Podtelezhnikov  <address@hidden>
+
+       [ftgrid,ftview,ftstring] Implement PNG printing.
+
+       * src/ftcommon.[hc] (FT_Display_Print): New function.
+       * src/{ftgrid,ftview,ftstring}.c (Process_Event): New event.
+
+       * Makefile: Compile with appropriate <ftoption.h> so that
+       FT_CONFIG_OPTION_USE_PNG status is inherited from the library build
+       and based on the libPNG avalability.
+
 2019-06-01  Alexei Podtelezhnikov  <address@hidden>
 
        [ftgrid,ftview,ftstring] Consolidate versioning.
diff --git a/Makefile b/Makefile
index dd88cbe..4c91e17 100644
--- a/Makefile
+++ b/Makefile
@@ -131,6 +131,7 @@ else
                   $(CFLAGS) \
                   $(ANSIFLAGS) \
                   $(INCLUDES:%=$I%) \
+                  $DFT_CONFIG_OPTIONS_H="<ftoption.h>" \
                   $DFT_CONFIG_MODULES_H="<ftmodule.h>"
 
   # Enable C99 for gcc to avoid warnings.
diff --git a/src/ftcommon.c b/src/ftcommon.c
index 4336ea9..61e7a59 100644
--- a/src/ftcommon.c
+++ b/src/ftcommon.c
@@ -39,6 +39,10 @@
 #include <string.h>
 #include <stdarg.h>
 
+#ifdef FT_CONFIG_OPTION_USE_PNG
+#include <png.h>
+#endif
+
 
 #ifdef _WIN32
 #define strcasecmp  _stricmp
@@ -186,6 +190,119 @@
   }
 
 
+  int
+  FTDemo_Display_Print( FTDemo_Display*  display,
+                        FT_String*       filename,
+                        FT_String*       ver_str )
+  {
+#ifdef FT_CONFIG_OPTION_USE_PNG
+    grBitmap*  bit    = display->bitmap;
+    int        width  = bit->width;
+    int        height = bit->rows;
+    int        color_type;
+
+    int code = 1;
+    FILE *fp = NULL;
+    png_structp png_ptr = NULL;
+    png_infop info_ptr = NULL;
+    png_bytep row = NULL;
+
+
+    /* Set color_type */
+    switch ( bit-> mode )
+    {
+    case gr_pixel_mode_gray:
+      color_type = PNG_COLOR_TYPE_GRAY;
+      break;
+    case gr_pixel_mode_rgb24:
+      color_type = PNG_COLOR_TYPE_RGB;
+      break;
+    case gr_pixel_mode_rgb32:
+      color_type = PNG_COLOR_TYPE_RGB_ALPHA;
+      break;
+    default:
+      fprintf( stderr, "Unsupported color type\n" );
+      goto Exit0;
+    }
+
+    /* Open file for writing (binary mode) */
+    fp = fopen( filename, "wb" );
+    if ( fp == NULL )
+    {
+      fprintf( stderr, "Could not open file %s for writing\n", filename );
+      goto Exit0;
+    }
+
+    /* Initialize write structure */
+    png_ptr = png_create_write_struct( PNG_LIBPNG_VER_STRING, NULL, NULL, NULL 
);
+    if ( png_ptr == NULL )
+    {
+       fprintf( stderr, "Could not allocate write struct\n" );
+       goto Exit1;
+    }
+
+    /* Initialize info structure */
+    info_ptr = png_create_info_struct( png_ptr );
+    if ( info_ptr == NULL )
+    {
+      fprintf( stderr, "Could not allocate info struct\n" );
+      goto Exit2;
+    }
+
+    /* Set up exception handling */
+    if ( setjmp( png_jmpbuf( png_ptr ) ) )
+    {
+      fprintf( stderr, "Error during png creation\n" );
+      goto Exit2;
+    }
+
+    png_init_io( png_ptr, fp );
+
+    /* Write header (8 bit colour depth) */
+    png_set_IHDR( png_ptr, info_ptr, width, height,
+                  8, color_type, PNG_INTERLACE_NONE,
+                  PNG_COMPRESSION_TYPE_BASE, PNG_FILTER_TYPE_BASE );
+
+    /* Record version string  */
+    if ( ver_str != NULL )
+    {
+      png_text text;
+
+
+      text.compression = PNG_TEXT_COMPRESSION_NONE;
+      text.key = "Software";
+      text.text = ver_str;
+      png_set_text( png_ptr, info_ptr, &text, 1 );
+    }
+
+    /* Set gamma */
+    png_set_gAMA( png_ptr, info_ptr, 1.0 / display->gamma );
+
+    png_write_info( png_ptr, info_ptr );
+
+    /* Write image rows */
+    row = bit->buffer;
+    if ( bit->pitch < 0 )
+      row -= ( bit->rows - 1 ) * bit->pitch;
+    while ( height-- )
+    {
+      png_write_row( png_ptr, row );
+      row += bit->pitch;
+    }
+
+    /* End write */
+    png_write_end( png_ptr, NULL );
+    code = 0;
+
+  Exit2:
+    png_destroy_write_struct( &png_ptr, &info_ptr );
+  Exit1:
+    fclose( fp );
+  Exit0:
+    return code;
+#endif /* FT_CONFIG_OPTION_USE_PNG */
+  }
+
   /*************************************************************************/
   /*************************************************************************/
   /*****                                                               *****/
diff --git a/src/ftcommon.h b/src/ftcommon.h
index e58b8b3..af7efe2 100644
--- a/src/ftcommon.h
+++ b/src/ftcommon.h
@@ -99,6 +99,12 @@
   FTDemo_Display_Clear( FTDemo_Display*  display );
 
 
+  /* dump display image in PNG format */
+  int
+  FTDemo_Display_Print( FTDemo_Display*  display,
+                        FT_String*       filename,
+                        FT_String*       ver_str );
+
   /*************************************************************************/
   /*************************************************************************/
   /*****                                                               *****/
diff --git a/src/ftgrid.c b/src/ftgrid.c
index 2b4dac8..fefe8e8 100644
--- a/src/ftgrid.c
+++ b/src/ftgrid.c
@@ -919,6 +919,7 @@
     grWriteln( "             anti-aliasing modes          F3, F4    adjust 
current axis by  " );
     grWriteln( "L           cycle through LCD                        1/50th of 
its range    " );
     grWriteln( "             filters                                           
             " );
+    grWriteln( "                                        P           print PNG 
file          " );
     grWriteln( "g, v        adjust gamma value          q, ESC      quit 
ftgrid             " );
     /*          |----------------------------------|    
|----------------------------------| */
     grLn();
@@ -1394,6 +1395,16 @@
       event_help();
       break;
 
+    case grKEY( 'P' ):
+      {
+        FT_String  str[64] = "ftgrid (FreeType) ";
+
+
+        FTDemo_Version( handle, str );
+        FTDemo_Display_Print( display, "ftgrid.png", str );
+      }
+      break;
+
     case grKEY( 'f' ):
       handle->autohint = !handle->autohint;
       status.header    = handle->autohint ? "forced auto-hinting is now on"
diff --git a/src/ftstring.c b/src/ftstring.c
index 10d3a2e..2635620 100644
--- a/src/ftstring.c
+++ b/src/ftstring.c
@@ -242,6 +242,9 @@
     grWriteln( "  F7        : big rotate counter-clockwise" );
     grWriteln( "  F8        : big rotate clockwise" );
     grLn();
+    grWriteln( "  P         : print PNG file" );
+    grWriteln( "  q,ESC     : quit" );
+    grLn();
     grWriteln( "press any key to exit this help screen" );
 
     grRefreshSurface( display->surface );
@@ -465,6 +468,16 @@
       event_help();
       goto Exit;
 
+    case grKEY( 'P' ):
+      {
+        FT_String  str[64] = "ftstring (FreeType) ";
+
+
+        FTDemo_Version( handle, str );
+        FTDemo_Display_Print( display, "ftstring.png", str );
+      }
+      goto Exit;
+
     case grKEY( 'b' ):
       handle->use_sbits = !handle->use_sbits;
       status.header     = handle->use_sbits
diff --git a/src/ftview.c b/src/ftview.c
index da6edc0..b1d6903 100644
--- a/src/ftview.c
+++ b/src/ftview.c
@@ -849,7 +849,7 @@
     grWriteln( "             engines (if available)                            
             " );
     grWriteln( "f           toggle forced auto-         Tab         cycle 
through charmaps  " );
     grWriteln( "             hinting (if hinting)                              
             " );
-    grWriteln( "w           toggle warping                                     
             " );
+    grWriteln( "w           toggle warping              P           print PNG 
file          " );
     grWriteln( "             (if available)             q, ESC      quit 
ftview             " );
     /*          |----------------------------------|    
|----------------------------------| */
     grLn();
@@ -1164,6 +1164,17 @@
       status.update = 1;
       break;
 
+    case grKEY( 'P' ):
+      {
+        FT_String  str[64] = "ftview (FreeType) ";
+
+
+        FTDemo_Version( handle, str );
+        FTDemo_Display_Print( display, "ftview.png", str );
+      }
+      status.update = 0;
+      break;
+
     case grKEY( 'b' ):
       handle->use_sbits = !handle->use_sbits;
       FTDemo_Update_Current_Flags( handle );