engine: common: imagelib: img_tga.c: refactor Targa encoder.

engine/common/imagelib/img_tga.c

@@ -236,9 +236,10 @@ Image_SaveTGA
 qboolean Image_SaveTGA( const char *name, rgbdata_t *pix )
 {
 	int		y, outsize, pixel_size;
-	const byte	*bufend, *in;
-	byte		*buffer, *out;
-	const char	*comment = "Generated by Xash ImageLib\0";
+	const uint8_t	*bufend, *in;
+	uint8_t		*buffer, *out;
+	tga_t		targa_header = {0};
+	const char	comment[] = "Generated by Xash ImageLib";
 
 	if( FS_FileExists( name, false ) && !Image_CheckFlag( IL_ALLOW_OVERWRITE ))
 		return false; // already existed
@@ -258,21 +259,36 @@ qboolean Image_SaveTGA( const char *name, rgbdata_t *pix )
 		return false;
 	}
 
-	outsize = pix->width * pix->height * pixel_size + 18 + Q_strlen( comment );
+	outsize = pix->width * pix->height * pixel_size;
+	outsize += sizeof( tga_t );
+	outsize += sizeof( comment ) - 1;
 
-	buffer = (byte *)Mem_Calloc( host.imagepool, outsize );
+	buffer = (uint8_t *)Mem_Malloc( host.imagepool, outsize );
 
 	// prepare header
-	buffer[0] = Q_strlen( comment ); // tga comment length
-	buffer[2] = 2; // uncompressed type
-	buffer[12] = (pix->width >> 0) & 0xFF;
-	buffer[13] = (pix->width >> 8) & 0xFF;
-	buffer[14] = (pix->height >> 0) & 0xFF;
-	buffer[15] = (pix->height >> 8) & 0xFF;
-	buffer[16] = ( pix->flags & IMAGE_HAS_ALPHA ) ? 32 : 24;
-	buffer[17] = ( pix->flags & IMAGE_HAS_ALPHA ) ? 8 : 0; // 8 bits of alpha
-	Q_strncpy( buffer + 18, comment, Q_strlen( comment )); 
-	out = buffer + 18 + Q_strlen( comment );
+	targa_header.id_length = sizeof( comment ) - 1; // tga comment length
+	targa_header.image_type = 2; // uncompressed type
+	targa_header.width = pix->width;
+	targa_header.height = pix->height;
+
+	if( pix->flags & IMAGE_HAS_ALPHA )
+	{
+		targa_header.pixel_size = 32;
+		targa_header.attributes = 8; // 8 bits of alpha
+	}
+	else
+	{
+		targa_header.pixel_size = 24;
+		targa_header.attributes = 0;
+	}
+
+	out = buffer;
+
+	memcpy( out, &targa_header, sizeof( tga_t ) );
+	out += sizeof( tga_t );
+
+	memcpy( out, comment, sizeof( comment ) - 1 );
+	out += sizeof( comment ) - 1;
 
 	switch( pix->type )
 	{
@@ -311,6 +327,7 @@ qboolean Image_SaveTGA( const char *name, rgbdata_t *pix )
 		}
 		break;
 	}	
+
 	FS_WriteFile( name, buffer, outsize );
 
 	Mem_Free( buffer );