import

DSTexCompress/FreeImage/Examples/OpenGL/TextureManager/TextureManager.cpp

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+//**********************************************
+//Singleton Texture Manager class
+//Written by Ben English
+//benjamin.english@oit.edu
+//
+//For use with OpenGL and the FreeImage library
+//**********************************************
+
+#include "TextureManager.h"
+
+TextureManager* TextureManager::m_inst(0);
+
+TextureManager* TextureManager::Inst()
+{
+	if(!m_inst)
+		m_inst = new TextureManager();
+
+	return m_inst;
+}
+
+TextureManager::TextureManager()
+{
+	// call this ONLY when linking with FreeImage as a static library
+	#ifdef FREEIMAGE_LIB
+		FreeImage_Initialise();
+	#endif
+}
+
+//these should never be called
+//TextureManager::TextureManager(const TextureManager& tm){}
+//TextureManager& TextureManager::operator=(const TextureManager& tm){}
+	
+TextureManager::~TextureManager()
+{
+	// call this ONLY when linking with FreeImage as a static library
+	#ifdef FREEIMAGE_LIB
+		FreeImage_DeInitialise();
+	#endif
+
+	UnloadAllTextures();
+	m_inst = 0;
+}
+
+bool TextureManager::LoadTexture(const char* filename, const unsigned int texID, GLenum image_format, GLint internal_format, GLint level, GLint border)
+{
+	//image format
+	FREE_IMAGE_FORMAT fif = FIF_UNKNOWN;
+	//pointer to the image, once loaded
+	FIBITMAP *dib(0);
+	//pointer to the image data
+	BYTE* bits(0);
+	//image width and height
+	unsigned int width(0), height(0);
+	//OpenGL's image ID to map to
+	GLuint gl_texID;
+	
+	//check the file signature and deduce its format
+	fif = FreeImage_GetFileType(filename, 0);
+	//if still unknown, try to guess the file format from the file extension
+	if(fif == FIF_UNKNOWN) 
+		fif = FreeImage_GetFIFFromFilename(filename);
+	//if still unkown, return failure
+	if(fif == FIF_UNKNOWN)
+		return false;
+
+	//check that the plugin has reading capabilities and load the file
+	if(FreeImage_FIFSupportsReading(fif))
+		dib = FreeImage_Load(fif, filename);
+	//if the image failed to load, return failure
+	if(!dib)
+		return false;
+
+	//retrieve the image data
+	bits = FreeImage_GetBits(dib);
+	//get the image width and height
+	width = FreeImage_GetWidth(dib);
+	height = FreeImage_GetHeight(dib);
+	//if this somehow one of these failed (they shouldn't), return failure
+	if((bits == 0) || (width == 0) || (height == 0))
+		return false;
+	
+	//if this texture ID is in use, unload the current texture
+	if(m_texID.find(texID) != m_texID.end())
+		glDeleteTextures(1, &(m_texID[texID]));
+
+	//generate an OpenGL texture ID for this texture
+	glGenTextures(1, &gl_texID);
+	//store the texture ID mapping
+	m_texID[texID] = gl_texID;
+	//bind to the new texture ID
+	glBindTexture(GL_TEXTURE_2D, gl_texID);
+	//store the texture data for OpenGL use
+	glTexImage2D(GL_TEXTURE_2D, level, internal_format, width, height,
+		border, image_format, GL_UNSIGNED_BYTE, bits);
+
+	//Free FreeImage's copy of the data
+	FreeImage_Unload(dib);
+
+	//return success
+	return true;
+}
+
+bool TextureManager::UnloadTexture(const unsigned int texID)
+{
+	bool result(true);
+	//if this texture ID mapped, unload it's texture, and remove it from the map
+	if(m_texID.find(texID) != m_texID.end())
+	{
+		glDeleteTextures(1, &(m_texID[texID]));
+		m_texID.erase(texID);
+	}
+	//otherwise, unload failed
+	else
+	{
+		result = false;
+	}
+
+	return result;
+}
+
+bool TextureManager::BindTexture(const unsigned int texID)
+{
+	bool result(true);
+	//if this texture ID mapped, bind it's texture as current
+	if(m_texID.find(texID) != m_texID.end())
+		glBindTexture(GL_TEXTURE_2D, m_texID[texID]);
+	//otherwise, binding failed
+	else
+		result = false;
+
+	return result;
+}
+
+void TextureManager::UnloadAllTextures()
+{
+	//start at the begginning of the texture map
+	std::map<unsigned int, GLuint>::iterator i = m_texID.begin();
+
+	//Unload the textures untill the end of the texture map is found
+	while(i != m_texID.end())
+		UnloadTexture(i->first);
+
+	//clear the texture map
+	m_texID.clear();
+}

DSTexCompress/FreeImage/Examples/OpenGL/TextureManager/TextureManager.h

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+//**********************************************
+//Singleton Texture Manager class
+//Written by Ben English
+//benjamin.english@oit.edu
+//
+//For use with OpenGL and the FreeImage library
+//**********************************************
+
+#ifndef TextureManager_H
+#define TextureManager_H
+
+#include <windows.h>
+#include <gl/gl.h>
+#include "FreeImage.h"
+#include <map>
+
+class TextureManager
+{
+public:
+	static TextureManager* Inst();
+	virtual ~TextureManager();
+
+	//load a texture an make it the current texture
+	//if texID is already in use, it will be unloaded and replaced with this texture
+	bool LoadTexture(const char* filename,	//where to load the file from
+		const unsigned int texID,			//arbitrary id you will reference the texture by
+											//does not have to be generated with glGenTextures
+		GLenum image_format = GL_RGB,		//format the image is in
+		GLint internal_format = GL_RGB,		//format to store the image in
+		GLint level = 0,					//mipmapping level
+		GLint border = 0);					//border size
+
+	//free the memory for a texture
+	bool UnloadTexture(const unsigned int texID);
+
+	//set the current texture
+	bool BindTexture(const unsigned int texID);
+
+	//free all texture memory
+	void UnloadAllTextures();
+
+protected:
+	TextureManager();
+	TextureManager(const TextureManager& tm);
+	TextureManager& operator=(const TextureManager& tm);
+
+	static TextureManager* m_inst;
+	std::map<unsigned int, GLuint> m_texID;
+};
+
+#endif

DSTexCompress/FreeImage/Examples/OpenGL/TextureManager/readme.txt

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+Hello everyone, this is my 2D texture manager class for OpenGL using the FreeImage Library.  
+
+Requirements:
+--------------------
+OpenGL
+STL map class
+FreeImage (included)
+
+
+Usage
+--------------------
+To load a texture, simply call the LoadTexture function:
+
+TextureManager::Inst()->LoadTexture("img\\bg.jpg", BACKGROUND_IMAGE_ID);
+
+This also binds the loaded texture as the current texture, so after calling it you may make any calls to glTexParameter you may need to specify the properties of the texture.
+
+When you are rendering, just call the TextureManager's BindImage function instead of glBindImage:
+
+TextureManager::Inst()->BindImage(BACKGROUND_IMAGE_ID);
+
+and then do your rendering as normal.
+--------------------
+
+
+Feel free to distribute this as you like, but mind the FreeImage licence included in license-fi.txt, and please don't take credit for my code.  If you modify it, be sure to mention me (Ben English) somewhere.
+
+Please send any comments or suggestions to me at benjamin.english@oit.edu
+
+
+Thanks to Herve Drolon for the FreeImage library, I've found it to be very useful!