GLContextManager.cpp

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#include "GLContextManager.hpp"
 
namespace BARE2D {
 
    GLContext::GLContext() {
        m_boundTextureIDs = new GLuint[GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS]{GL_TEXTURE_2D};
    }
    
    GLContext::~GLContext() {
        delete[] m_boundTextureIDs;
    }
    
    void GLContext::setActiveTexture(GLenum texture)
    {
        // If we already have the same texture active, why bother OpenGL?
        if(m_activeTexture != texture) {
            m_activeTexture = texture;
            glActiveTexture(texture);
        }
    }
 
    void GLContext::bindTexture(GLenum target, GLenum texture)
    {
        // Make sure that the active texture's slot doesn't already have `texture` active
        unsigned int index = (unsigned int)(m_activeTexture - GL_TEXTURE0);
        if(m_boundTextureIDs[index] != texture) {
            m_boundTextureIDs[index] = texture;
            glBindTexture(target, texture);
        }
    }
    
    void GLContext::unbindTexture(GLenum target, GLenum textureslot) {
        setActiveTexture(textureslot);
        bindTexture(target, 0);
    }
    
    GLuint GLContext::getBoundTexture() {
        unsigned int index = (unsigned int)(m_activeTexture - GL_TEXTURE0);
        return m_boundTextureIDs[index];
    }
 
    GLContext* GLContextManager::m_context = nullptr;
    
    GLContext* GLContextManager::getContext()
    {
        if(m_context) {
            return m_context;
        } else {
            m_context = new GLContext();
            return m_context;
        }
    }
 
}