/*
-----------------------------------------------------------------------------
This source file is part of OGRE
    (Object-oriented Graphics Rendering Engine)
For the latest info, see http://www.ogre3d.org

Copyright (c) 2008 Renato Araujo Oliveira Filho <renatox@gmail.com>
Copyright (c) 2000-2009 Torus Knot Software Ltd

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.
-----------------------------------------------------------------------------
*/

#include "OgreGLESTexture.h"
#include "OgreGLESSupport.h"
#include "OgreGLESPixelFormat.h"
#include "OgreGLESRenderSystem.h"
#include "OgreGLESHardwarePixelBuffer.h"

#include "OgreRoot.h"

namespace Ogre {
    static inline void doImageIO(const String &name, const String &group,
                                 const String &ext,
                                 std::vector<Image> &images,
                                 Resource *r)
    {
        size_t imgIdx = images.size();
        images.push_back(Image());

        DataStreamPtr dstream =
            ResourceGroupManager::getSingleton().openResource(
                name, group, true, r);

        images[imgIdx].load(dstream, ext);
    }

    GLESTexture::GLESTexture(ResourceManager* creator, const String& name,
                             ResourceHandle handle, const String& group, bool isManual,
                             ManualResourceLoader* loader, GLESSupport& support)
        : Texture(creator, name, handle, group, isManual, loader),
          mTextureID(0), mGLSupport(support)
    {
    }

    GLESTexture::~GLESTexture()
    {
        // have to call this here rather than in Resource destructor
        // since calling virtual methods in base destructors causes crash
        if (isLoaded())
        {
            unload();
        }
        else
        {
            freeInternalResources();
        }
    }

    GLenum GLESTexture::getGLESTextureTarget(void) const
    {
        return GL_TEXTURE_2D;
    }

    // Creation / loading methods
    void GLESTexture::createInternalResourcesImpl(void)
    {
		// Convert to nearest power-of-two size if required
        mWidth = GLESPixelUtil::optionalPO2(mWidth);
        mHeight = GLESPixelUtil::optionalPO2(mHeight);
        mDepth = GLESPixelUtil::optionalPO2(mDepth);

		// Adjust format if required
        mFormat = TextureManager::getSingleton().getNativeFormat(TEX_TYPE_2D, mFormat, mUsage);

		// Check requested number of mipmaps
        size_t maxMips = GLESPixelUtil::getMaxMipmaps(mWidth, mHeight, mDepth, mFormat);
        
        if(PixelUtil::isCompressed(mFormat) && (mNumMipmaps == 0))
            mNumRequestedMipmaps = 0;
        
        mNumMipmaps = mNumRequestedMipmaps;
        if (mNumMipmaps > maxMips)
            mNumMipmaps = maxMips;

		// Generate texture name
        glGenTextures(1, &mTextureID);
        GL_CHECK_ERROR;

		// Set texture type
        glBindTexture(GL_TEXTURE_2D, mTextureID);
        GL_CHECK_ERROR;

        // Set some misc default parameters, these can of course be changed later
        glTexParameteri(GL_TEXTURE_2D,
                        GL_TEXTURE_MIN_FILTER, GL_LINEAR_MIPMAP_NEAREST);
        GL_CHECK_ERROR;
        glTexParameteri(GL_TEXTURE_2D,
                        GL_TEXTURE_MAG_FILTER, GL_NEAREST);
        GL_CHECK_ERROR;
        glTexParameteri(GL_TEXTURE_2D,
                        GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
        GL_CHECK_ERROR;
        glTexParameteri(GL_TEXTURE_2D,
                        GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
        GL_CHECK_ERROR;

		// If we can do automip generation and the user desires this, do so
        mMipmapsHardwareGenerated =
            Root::getSingleton().getRenderSystem()->getCapabilities()->hasCapability(RSC_AUTOMIPMAP) && !PixelUtil::isCompressed(mFormat);

        if ((mUsage & TU_AUTOMIPMAP) &&
            mNumRequestedMipmaps && mMipmapsHardwareGenerated)
        {
            glTexParameteri(GL_TEXTURE_2D, GL_GENERATE_MIPMAP, GL_TRUE);
            GL_CHECK_ERROR;
        }

        // Allocate internal buffer so that glTexSubImageXD can be used
        // Internal format
        GLenum format = GLESPixelUtil::getClosestGLInternalFormat(mFormat, mHwGamma);
        GLenum datatype = GLESPixelUtil::getGLOriginDataType(mFormat);
        size_t width = mWidth;
        size_t height = mHeight;
        size_t depth = mDepth;

        if (PixelUtil::isCompressed(mFormat))
        {
            // Compressed formats
            size_t size = PixelUtil::getMemorySize(mWidth, mHeight, mDepth, mFormat);

            // Provide temporary buffer filled with zeroes as glCompressedTexImageXD does not
            // accept a 0 pointer like normal glTexImageXD
            // Run through this process for every mipmap to pregenerate mipmap pyramid

            uint8* tmpdata = OGRE_NEW_FIX_FOR_WIN32 uint8[size];
            memset(tmpdata, 0, size);
            for (size_t mip = 0; mip <= mNumMipmaps; mip++)
            {
                size = PixelUtil::getMemorySize(width, height, depth, mFormat);

                glCompressedTexImage2D(GL_TEXTURE_2D,
                                       mip,
                                       format,
                                       width, height,
                                       0,
                                       size,
                                       tmpdata);
                GL_CHECK_ERROR;

//                LogManager::getSingleton().logMessage("GLESTexture::create - Mip: " + StringConverter::toString(mip) +
//                                                      " Width: " + StringConverter::toString(width) +
//                                                      " Height: " + StringConverter::toString(height) +
//                                                      " Internal Format: " + StringConverter::toString(format)
//                                                      );

                if(width > 1)
                {
                    width = width / 2;
                }
                if(height > 1)
                {
                    height = height / 2;
                }
                if(depth > 1)
                {
                    depth = depth / 2;
                }
            }
            OGRE_DELETE [] tmpdata;
        }
        else
        {
            // Run through this process to pregenerate mipmap pyramid
            for(size_t mip = 0; mip <= mNumMipmaps; mip++)
            {
                glTexImage2D(GL_TEXTURE_2D,
                             mip,
                             format,
                             width, height,
                             0,
                             format,
                             datatype, 0);
                GL_CHECK_ERROR;

                if (width > 1)
                {
                    width = width / 2;
                }
                if (height > 1)
                {
                    height = height / 2;
                }
            }
        }

        _createSurfaceList();

        // Get final internal format
        mFormat = getBuffer(0,0)->getFormat();
    }

    void GLESTexture::createRenderTexture(void)
    {
        // Create the GL texture
        // This already does everything necessary
        createInternalResources();
    }

    void GLESTexture::prepareImpl()
    {
        if (mUsage & TU_RENDERTARGET) return;

        String baseName, ext;
        size_t pos = mName.find_last_of(".");
        baseName = mName.substr(0, pos);

        if (pos != String::npos)
        {
            ext = mName.substr(pos+1);
        }

        LoadedImages loadedImages = LoadedImages(OGRE_NEW_FIX_FOR_WIN32 std::vector<Image>());

        if (mTextureType == TEX_TYPE_2D)
        {
            doImageIO(mName, mGroup, ext, *loadedImages, this);

            // If this is a volumetric texture set the texture type flag accordingly.
            if ((*loadedImages)[0].getDepth() > 1)
            {
                OGRE_EXCEPT(Exception::ERR_NOT_IMPLEMENTED,
                            "**** Unsupported 3D texture type ****",
                            "GLESTexture::prepare" );
            }
            
			// If PVRTC and 0 custom mipmap disable auto mip generation and disable software mipmap creation
            PixelFormat imageFormat = (*loadedImages)[0].getFormat();
			if (imageFormat == PF_PVRTC_RGB2 || imageFormat == PF_PVRTC_RGBA2 ||
                imageFormat == PF_PVRTC_RGB4 || imageFormat == PF_PVRTC_RGBA4)
			{
                size_t imageMips = (*loadedImages)[0].getNumMipmaps();
                if (imageMips == 0)
                {
                    mNumMipmaps = mNumRequestedMipmaps = imageMips;
                    // Disable flag for auto mip generation
                    mUsage &= ~TU_AUTOMIPMAP;
                }
			}
        }
        else
        {
            OGRE_EXCEPT(Exception::ERR_NOT_IMPLEMENTED,
                        "**** Unknown texture type ****",
                        "GLESTexture::prepare");
        }

        mLoadedImages = loadedImages;
    }

    void GLESTexture::unprepareImpl()
    {
        mLoadedImages.setNull();
    }

    void GLESTexture::loadImpl()
    {
        if (mUsage & TU_RENDERTARGET)
        {
            createRenderTexture();
            return;
        }

        // Now the only copy is on the stack and will be cleaned in case of
        // exceptions being thrown from _loadImages
        LoadedImages loadedImages = mLoadedImages;
        mLoadedImages.setNull();

        // Call internal _loadImages, not loadImage since that's external and 
        // will determine load status etc again
        ConstImagePtrList imagePtrs;

        for (size_t i = 0; i < loadedImages->size(); ++i)
        {
            imagePtrs.push_back(&(*loadedImages)[i]);
        }

        _loadImages(imagePtrs);
    }

    void GLESTexture::freeInternalResourcesImpl()
    {
        mSurfaceList.clear();
        glDeleteTextures(1, &mTextureID);
        GL_CHECK_ERROR;
    }

    void GLESTexture::_createSurfaceList()
    {
        mSurfaceList.clear();

        // For all faces and mipmaps, store surfaces as HardwarePixelBufferSharedPtr
        bool wantGeneratedMips = (mUsage & TU_AUTOMIPMAP)!=0;

        // Do mipmapping in software? (uses GLU) For some cards, this is still needed. Of course,
        // only when mipmap generation is desired.
        bool doSoftware = wantGeneratedMips && !mMipmapsHardwareGenerated && getNumMipmaps();

        for (size_t face = 0; face < getNumFaces(); face++)
        {
			size_t width = mWidth;
			size_t height = mHeight;
            for (size_t mip = 0; mip <= getNumMipmaps(); mip++)
            {
                GLESHardwarePixelBuffer *buf = OGRE_NEW GLESTextureBuffer(mName,
                                                                     getGLESTextureTarget(),
                                                                     mTextureID,
                                                                     width, height,
                                                                     GLESPixelUtil::getClosestGLInternalFormat(mFormat, mHwGamma),
                                                                     GLESPixelUtil::getGLOriginDataType(mFormat),
                                                                     face,
                                                                     mip,
                                                                     static_cast<HardwareBuffer::Usage>(mUsage),
                                                                     doSoftware && mip==0, mHwGamma, mFSAA);

                mSurfaceList.push_back(HardwarePixelBufferSharedPtr(buf));

                /// Check for error
                if (buf->getWidth() == 0 ||
                    buf->getHeight() == 0 ||
                    buf->getDepth() == 0)
                {
                    OGRE_EXCEPT(
                        Exception::ERR_RENDERINGAPI_ERROR,
                        "Zero sized texture surface on texture "+getName()+
                            " face "+StringConverter::toString(face)+
                            " mipmap "+StringConverter::toString(mip)+
                            ". The GL driver probably refused to create the texture.",
                            "GLESTexture::_createSurfaceList");
                }
            }
        }
    }

    HardwarePixelBufferSharedPtr GLESTexture::getBuffer(size_t face, size_t mipmap)
    {
        if (face >= getNumFaces())
        {
            OGRE_EXCEPT(Exception::ERR_INVALIDPARAMS,
                        "Face index out of range",
                        "GLESTexture::getBuffer");
        }

        if (mipmap > mNumMipmaps)
        {
            OGRE_EXCEPT(Exception::ERR_INVALIDPARAMS,
                        "Mipmap index out of range",
                        "GLESTexture::getBuffer");
        }

        unsigned int idx = face * (mNumMipmaps + 1) + mipmap;
        assert(idx < mSurfaceList.size());
        return mSurfaceList[idx];
    }
}