From abb5ca2a446f78e9b0844d3d9078dd51e38afc04 Mon Sep 17 00:00:00 2001
From: Pavel Krajcevski <pavel@cs.unc.edu>
Date: Sun, 26 Aug 2012 19:05:18 -0400
Subject: [PATCH] Add some more skeleton code to prepare for png image loading.

---
 IO/CMakeLists.txt   | 14 ++++++++++++++
 IO/ImageFile.cpp    | 37 ++++++++++++++++++++++++++----------
 IO/ImageFile.h      | 17 +++++------------
 IO/ImageLoader.h    | 46 +++++++++++++++++++++++++++++++++++++++++++++
 IO/ImageLoaderPNG.h | 14 ++++++++++++++
 5 files changed, 106 insertions(+), 22 deletions(-)
 create mode 100644 IO/ImageLoader.h
 create mode 100644 IO/ImageLoaderPNG.h

diff --git a/IO/CMakeLists.txt b/IO/CMakeLists.txt
index e69de29..c460015 100644
--- a/IO/CMakeLists.txt
+++ b/IO/CMakeLists.txt
@@ -0,0 +1,14 @@
+
+SET( SOURCES
+	ImageFile.cpp
+)
+
+SET( HEADERS
+	ImageLoader.h
+	ImageFile.h
+)
+
+ADD_LIBRARY(TexCompIO
+	${SOURCES}
+	${HEADERS}
+)
diff --git a/IO/ImageFile.cpp b/IO/ImageFile.cpp
index fd26238..00ee9a4 100644
--- a/IO/ImageFile.cpp
+++ b/IO/ImageFile.cpp
@@ -1,10 +1,11 @@
 #include "ImageFile.h"
+#include <string.h>
 
 ImageFile::ImageFile(const char *filename) : 
-  m_PixelData(0)
+  m_PixelData(0),
+  m_FileFormat(  DetectFileFormat(filename) )
 {
   unsigned char *rawData = ReadFileData(filename);
-  DetectFileFormat(filename);
   LoadImage(rawData);
   delete [] rawData;
 }
@@ -24,17 +25,33 @@ ImageFile::~ImageFile() {
   }
 }
 
-void ImageFile::GetPixels() const {
+EImageFileFormat ImageFile::DetectFileFormat(const char *filename) {
 
+  int len = strlen(filename);
+  if(len >= 256) {
+    // !FIXME! Report Error...
+    return kNumImageFileFormats;
+  }
+
+  int dotPos = len - 1;
+
+  while(dotPos >= 0 && filename[dotPos--] != '.');
+
+  if(dotPos < 0) {
+    // !FIXME! Report Error.....
+    return kNumImageFileFormats;
+  }
+
+  const char *ext = &filename[dotPos];
+
+  if(strcmp(ext, ".png") == 0) {
+    return eFileFormat_PNG;
+  }
+  return kNumImageFileFormats;
 }
 
-EImageFileFormat ImageFile::DetectFileFormat() {
-}
-
-void ImageFile::LoadImage(const unsigend char *rawImageData) {
-}
-
-void ImageFile::LoadPNGImage(const unsigned char *rawImageData) {
+bool ImageFile::LoadImage(const unsigned char *rawImageData) {
+  return false;
 }
 
 #ifdef _MSC_VER
diff --git a/IO/ImageFile.h b/IO/ImageFile.h
index f01f879..34d6593 100644
--- a/IO/ImageFile.h
+++ b/IO/ImageFile.h
@@ -1,11 +1,7 @@
-#ifedef _IMAGE_FILE_H_ 
+#ifndef _IMAGE_FILE_H_ 
 #define _IMAGE_FILE_H_ 
 
-enum EImageFileFormat {
-  eFileFormat_PNG,
-
-  kNumImageFileFormats
-};
+#include "ImageLoader.h"
 
 class ImageFile {
 
@@ -15,8 +11,8 @@ public:
   ImageFile(const char *filename, EImageFileFormat format);
   ~ImageFile();
 
-  void GetWidth() const { return m_Width; }
-  void GetHeight() const { return m_Height; }
+  unsigned int GetWidth() const { return m_Width; }
+  unsigned int GetHeight() const { return m_Height; }
   const unsigned char *GetPixels() const { return m_PixelData; }
 
  private:
@@ -27,11 +23,8 @@ public:
   const EImageFileFormat m_FileFormat;
 
   static unsigned char *ReadFileData(const char *filename);
-  static EFileFormat DetectFileFormat(const char *filename);
+  static EImageFileFormat DetectFileFormat(const char *filename);
 
   bool LoadImage(const unsigned char *rawImageData);
-  bool LoadPNGImage(const unsigned char *rawImageData);
 };
-
-
 #endif // _IMAGE_FILE_H_ 
diff --git a/IO/ImageLoader.h b/IO/ImageLoader.h
new file mode 100644
index 0000000..4ce6473
--- /dev/null
+++ b/IO/ImageLoader.h
@@ -0,0 +1,46 @@
+#ifndef _IMAGE_LOADER_H_
+#define _IMAGE_LOADER_H_
+
+enum EImageFileFormat {
+  eFileFormat_PNG,
+
+  kNumImageFileFormats
+};
+
+class ImageLoader {
+
+ protected:
+  int m_RedChannelPrecision;
+  unsigned char *m_RedData;
+
+  int m_GreenChannelPrecision;
+  unsigned char *m_GreenData;
+
+  int m_BlueChannelPrecision;
+  unsigned char *m_BlueData;
+  
+  int m_AlphaChannelPrecision;
+  unsigned char *m_AlphaData;
+
+  const unsigned char *const m_RawData;
+
+  ImageLoader(const unsigned char *rawData);
+  virtual ~ImageLoader();
+
+ public:
+  virtual void ReadData() = 0;
+
+  int GetRedChannelPrecision() const { return m_RedChannelPrecision; }
+  unsigned char * GetRedPixelData() const { return m_RedData; }
+
+  int GetGreenChannelPrecision() const { return m_GreenChannelPrecision; }
+  unsigned char * GetGreenPixelData() const { return m_GreenData; }
+
+  int GetBlueChannelPrecision() const { return m_BlueChannelPrecision; }
+  unsigned char * GetBluePixelData() const { return m_BlueData; }
+
+  int GetAlphaChannelPrecision() const { return m_AlphaChannelPrecision; }
+  unsigned char * GetAlphaPixelData() const { return m_AlphaData; }
+};
+
+#endif // _IMAGE_LOADER_H_
diff --git a/IO/ImageLoaderPNG.h b/IO/ImageLoaderPNG.h
new file mode 100644
index 0000000..d2bf7cf
--- /dev/null
+++ b/IO/ImageLoaderPNG.h
@@ -0,0 +1,14 @@
+#ifndef _IMAGE_LOADER_PNG_H_
+#define _IMAGE_LOADER_PNG_H_
+
+#include "ImageLoader.h"
+
+class ImageLoaderPNG : public ImageLoader {
+ public:
+  ImageLoader(const unsigned char *rawData);
+  virtual ~ImageLoader();
+
+  void ReadData();
+};
+
+#endif // _IMAGE_LOADER_H_