assimp/tools/assimp_view/MaterialManager.h

/*
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Open Asset Import Library (assimp)
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All rights reserved.

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  following disclaimer.

* Redistributions in binary form must reproduce the above
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*/

#pragma once

#include <map>

#include "AssetHelper.h"

namespace AssimpView
{

    //-------------------------------------------------------------------------------
    /* Helper class to create, access and destroy materials
    */
    //-------------------------------------------------------------------------------
    class CMaterialManager
    {
    private:

        friend class CDisplay;

        // default constructor
        CMaterialManager()
            : m_iShaderCount( 0 ), sDefaultTexture() {}

        ~CMaterialManager() {
            if( sDefaultTexture ) {
                sDefaultTexture->Release();
            }
            Reset();
        }

    public:

        //------------------------------------------------------------------
        // Singleton accessors
        static CMaterialManager s_cInstance;
        inline static CMaterialManager& Instance()
        {
            return s_cInstance;
        }

        //------------------------------------------------------------------
        // Delete all resources of a given material
        //
        // Must be called before CreateMaterial() to prevent memory leaking
        void DeleteMaterial( AssetHelper::MeshHelper* pcIn );

        //------------------------------------------------------------------
        // Create the material for a mesh.
        //
        // The function checks whether an identical shader is already in use.
        // A shader is considered to be identical if it has the same input
        // signature and takes the same number of texture channels.
        int CreateMaterial( AssetHelper::MeshHelper* pcMesh,
            const aiMesh* pcSource );

        //------------------------------------------------------------------
        // Setup the material for a given mesh
        // pcMesh Mesh to be rendered
        // pcProj Projection matrix
        // aiMe Current world matrix
        // pcCam Camera matrix
        // vPos Position of the camera
        // TODO: Extract camera position from matrix ...
        //
        int SetupMaterial( AssetHelper::MeshHelper* pcMesh,
            const aiMatrix4x4& pcProj,
            const aiMatrix4x4& aiMe,
            const aiMatrix4x4& pcCam,
            const aiVector3D& vPos );

        //------------------------------------------------------------------
        // End the material for a given mesh
        // Called after mesh rendering is complete
        // pcMesh Mesh object
        int EndMaterial( AssetHelper::MeshHelper* pcMesh );

        //------------------------------------------------------------------
        // Recreate all specular materials depending on the current
        // specularity settings
        //
        // Diffuse-only materials are ignored.
        // Must be called after specular highlights have been toggled
        int UpdateSpecularMaterials();

        //------------------------------------------------------------------
        // find a valid path to a texture file
        //
        // Handle 8.3 syntax correctly, search the environment of the
        // executable and the asset for a texture with a name very similar
        // to a given one
        int FindValidPath( aiString* p_szString );

        //------------------------------------------------------------------
        // Load a texture into memory and create a native D3D texture resource
        //
        // The function tries to find a valid path for a texture
        int LoadTexture( IDirect3DTexture9** p_ppiOut, aiString* szPath );


        //------------------------------------------------------------------
        // Getter for m_iShaderCount
        //
        inline unsigned int GetShaderCount()
        {
            return this->m_iShaderCount;
        }

        //------------------------------------------------------------------
        // Reset the state of the class
        // Called whenever a new asset is loaded
        inline void Reset()
        {
            this->m_iShaderCount = 0;
            for( TextureCache::iterator it = sCachedTextures.begin(); it != sCachedTextures.end(); ++it ) {
                ( *it ).second->Release();
            }
            sCachedTextures.clear();
        }

    private:

        //------------------------------------------------------------------
        // find a valid path to a texture file
        //
        // Handle 8.3 syntax correctly, search the environment of the
        // executable and the asset for a texture with a name very similar
        // to a given one
        bool TryLongerPath( char* szTemp, aiString* p_szString );

        //------------------------------------------------------------------
        // Setup the default texture for a texture channel
        //
        // Generates a default checker pattern for a texture
        int SetDefaultTexture( IDirect3DTexture9** p_ppiOut );

        //------------------------------------------------------------------
        // Convert a height map to a normal map if necessary
        //
        // The function tries to detect the type of a texture automatically.
        // However, this won't work in every case.
        void HMtoNMIfNecessary( IDirect3DTexture9* piTexture,
            IDirect3DTexture9** piTextureOut,
            bool bWasOriginallyHM = true );

        //------------------------------------------------------------------
        // Search for non-opaque pixels in a texture
        //
        // A pixel is considered to be non-opaque if its alpha value is
        // less than 255
        //------------------------------------------------------------------
        bool HasAlphaPixels( IDirect3DTexture9* piTexture );

    private:

        //
        // Specifies the number of different shaders generated for
        // the current asset. This number is incremented by CreateMaterial()
        // each time a shader isn't found in cache and needs to be created
        //
        unsigned int m_iShaderCount;
        IDirect3DTexture9* sDefaultTexture;

        typedef std::map<std::string, IDirect3DTexture9*> TextureCache;
        TextureCache sCachedTextures;
    };

}