From ffe01aef80c5eddd650d037a80df76ca4932d135 Mon Sep 17 00:00:00 2001
From: Joel Bodenmann <joel@embedded.pro>
Date: Tue, 10 Jan 2017 10:39:07 +0100
Subject: [PATCH] Adding GDISP_IMAGE_PNG_FILE_BUFFER_SIZE configuration option

---
 gfxconf.example.h           |  1 +
 src/gdisp/gdisp_image_png.c | 12 +++---------
 src/gdisp/gdisp_options.h   | 13 +++++++++++--
 3 files changed, 15 insertions(+), 11 deletions(-)

diff --git a/gfxconf.example.h b/gfxconf.example.h
index 31a6b8a6..c7b836bf 100644
--- a/gfxconf.example.h
+++ b/gfxconf.example.h
@@ -137,6 +137,7 @@
 //        #define GDISP_NEED_IMAGE_PNG_RGBALPHA_8      TRUE
 //        #define GDISP_NEED_IMAGE_PNG_RGBALPHA_16     TRUE
 //        #define GDISP_IMAGE_PNG_BLIT_BUFFER_SIZE     32
+//        #define GDISP_IMAGE_PNG_FILE_BUFFER_SIZE     8
 //    #define GDISP_NEED_IMAGE_ACCOUNTING              FALSE
 
 //#define GDISP_NEED_PIXMAP                            FALSE
diff --git a/src/gdisp/gdisp_image_png.c b/src/gdisp/gdisp_image_png.c
index 9fa1c68e..1b3c2469 100644
--- a/src/gdisp/gdisp_image_png.c
+++ b/src/gdisp/gdisp_image_png.c
@@ -11,12 +11,6 @@
 
 #include "gdisp_image_support.h"
 
-/**
- * How big a byte array to use for input file buffer
- * Bigger is faster but uses more RAM.
- * Must be more than 8 bytes
- */
-#define PNG_FILE_BUFFER_SIZE	8
 /**
  * How big a byte array to use for inflate decompression
  * Bigger is faster but uses more RAM.
@@ -73,7 +67,7 @@ typedef struct PNG_input {
 	uint8_t		*pbuf;							// The pointer to the next byte
 	uint32_t	chunklen;						// The number of bytes left in the current PNG chunk
 	uint32_t	chunknext;						// The file position of the next PNG chunk
-	uint8_t		buf[PNG_FILE_BUFFER_SIZE];		// Must be a minimum of 8 bytes to hold a chunk header
+	uint8_t		buf[GDISP_IMAGE_PNG_FILE_BUFFER_SIZE];		// Must be a minimum of 8 bytes to hold a chunk header
 	} PNG_input;
 
 // Handle the display output and windowing
@@ -191,8 +185,8 @@ gotchunk:
 
 	// Try to read data some from the chunk
 	sz = d->i.chunklen;
-	if (sz > PNG_FILE_BUFFER_SIZE)
-		sz = PNG_FILE_BUFFER_SIZE;
+	if (sz > GDISP_IMAGE_PNG_FILE_BUFFER_SIZE)
+		sz = GDISP_IMAGE_PNG_FILE_BUFFER_SIZE;
 	if (gfileRead(d->i.f, d->i.buf, sz) != sz)
 		return FALSE;
 	d->i.chunklen -= sz;
diff --git a/src/gdisp/gdisp_options.h b/src/gdisp/gdisp_options.h
index ec043769..32429cde 100644
--- a/src/gdisp/gdisp_options.h
+++ b/src/gdisp/gdisp_options.h
@@ -390,7 +390,7 @@
 	#endif
 	/**
 	 * @brief   The BMP blit buffer size.
-	 * @details	Defaults to TRUE
+	 * @details	Defaults to 32
 	 * @note 	Bigger is faster but requires more RAM.
 	 * @note 	This must be greater than 40 bytes and 32 pixels as we read our headers into this space as well.
 	 */
@@ -520,12 +520,21 @@
 	#endif
 	/**
 	 * @brief   The PNG blit buffer size in pixels.
-	 * @details	Defaults to TRUE
+	 * @details	Defaults to 32
 	 * @note 	Bigger is faster but requires more RAM.
 	 */
 	#ifndef GDISP_IMAGE_PNG_BLIT_BUFFER_SIZE
 		#define GDISP_IMAGE_PNG_BLIT_BUFFER_SIZE	32
 	#endif
+	/**
+	 * @brief   The PNG input file buffer size in bytes.
+	 * @details	Defaults to 8
+	 * @note 	Bigger is faster but requires more RAM.
+	 * @note 	Must be >= 8
+	 */
+	#ifndef GDISP_IMAGE_PNG_FILE_BUFFER_SIZE
+		#define GDISP_IMAGE_PNG_FILE_BUFFER_SIZE	8
+	#endif
 /**
  * @}
  *