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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();
}
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