// Developed by Neil Kemp: http://neilkemp.us
// Licensed under the MIT license: http://www.opensource.org/licenses/mit-license.php


#ifndef BOOL
	#define BOOL	int
	#define FALSE	0
	#define TRUE	1
#endif

// Globals
IDirect3DSurface9*					select_surface;
IDirect3DSurface9*					select_depth_surface;
IDirect3DSurface9*					select_memory_surface;


// Create the select surface - Must be released on lost device and recreated on device reset
BOOL create_select_surface(IDirect3DDevice9* device_pointer, const D3DPRESENT_PARAMETERS& d3dpp)
{
	// Assertions
	_ASSERT(device_pointer != 0);


	// Create select render surface
	if(FAILED(device_pointer->CreateRenderTarget(d3dpp.BackBufferWidth, d3dpp.BackBufferHeight, D3DFMT_X8R8G8B8, D3DMULTISAMPLE_NONE, 0, TRUE, &select_surface, 0)))
	{	
		MessageBox(_T("Failed to create D3D9 select surface."), _T("Unexpected Error"), MB_OK | MB_ICONEXCLAMATION);
		return FALSE;
	}

	// Create select depth surface
	if(FAILED(device_pointer->CreateDepthStencilSurface(d3dpp.BackBufferWidth, d3dpp.BackBufferHeight, D3DFMT_D16, D3DMULTISAMPLE_NONE, 0, TRUE, &select_depth_surface, 0)))
	{	
		MessageBox(_T("Failed to create D3D9 select depth surface."), _T("Unexpected Error"), MB_OK | MB_ICONEXCLAMATION);
		return FALSE;		
	}
	
	// Create select offscreen surface
    if(FAILED(device_pointer->CreateOffscreenPlainSurface(d3dpp.BackBufferWidth, d3dpp.BackBufferHeight, D3DFMT_X8R8G8B8, 
														  D3DPOOL_SYSTEMMEM, &select_memory_surface, 0)))
	{	
		MessageBox(_T("Failed to create D3D9 select memory surface."), _T("Unexpected Error"), MB_OK | MB_ICONEXCLAMATION);
		return FALSE;
	}
	return TRUE;
}

// Render the nodes to the select surface with index encoded colors
BOOL render_select_surface(IDirect3DDevice9* device_pointer)
{
	// Assertions
	_ASSERT(device_pointer != 0);
	_ASSERT(select_surface != 0);
	_ASSERT(select_depth_surface != 0);
	_ASSERT(select_memory_surface != 0);

	// Local data
	D3DMATERIAL9			material;
	D3DCOLOR				saved_ambient;
	unsigned int			count, i;	
	int						R, G, B;


	// Start rendering
	device_pointer->SetRenderTarget(0, select_surface);
	device_pointer->SetDepthStencilSurface(select_depth_surface);
	device_pointer->Clear(0, NULL, D3DCLEAR_TARGET | D3DCLEAR_ZBUFFER, D3DCOLOR_RGBA(0, 0, 0, 255), 1.0f, 0);
	device_pointer->BeginScene();

	// ---------------------

		// Save the current ambient color
		device_pointer->GetRenderState(D3DRS_AMBIENT, &saved_ambient);

		// !! IMPORTANT - for perfect color storage
		// Set texture operation to choose diffuse arg2		
		device_pointer->SetTextureStageState(0, D3DTSS_COLOROP, D3DTOP_SELECTARG2); 

		// Set up a white material			
		ZeroMemory(&material, sizeof(D3DMATERIAL9));
		material.Diffuse.r	= 1.0f;
		material.Diffuse.g	= 1.0f;
		material.Diffuse.b	= 1.0f;
		material.Diffuse.a	= 1.0f;
		material.Ambient.r	= 1.0f;
		material.Ambient.g	= 1.0f;
		material.Ambient.b	= 1.0f;
		material.Ambient.a	= 1.0f;
		device_pointer->SetMaterial(&material);
		
		// Enable alpha test
		device_pointer->SetRenderState(D3DRS_ALPHAREF, (DWORD)0x00000022);	
		device_pointer->SetRenderState(D3DRS_ALPHAFUNC, D3DCMP_GREATER);
		device_pointer->SetRenderState(D3DRS_ALPHATESTENABLE, TRUE);		

		// ---------------------

		// Initialize node RGB colors
		R		= 0;
		G		= 0;
		B		= 1;
		
		// TODO You enter the number of nodes to render
		count = ??	
		for(i=0; i<count; i++)
		{
			// Encode color with index - at i
			if(B == 256)
			{	G++;
				B = 0;
				if(G == 256)
				{	R++;
					G = 0;							
				}
			}

			// Set the node color as the ambient color - because of material and color operation the result is a painted node
			device_pointer->SetRenderState(D3DRS_AMBIENT, D3DCOLOR_RGBA(R, G, B, 255));

			// TODO Set node texture with alpha
			device_pointer->SetTexture(0, node_texture);

			// TODO Render node i with fixed function lighting
			
			B++;
		}

		// ---------------------

		// Disable alpha test
		device_pointer->SetRenderState(D3DRS_ALPHATESTENABLE, FALSE);

		// Restore texture operation to modulate
		device_pointer->SetTextureStageState(0, D3DTSS_COLOROP, D3DTOP_MODULATE); 		

		// Restore the ambient color
		device_pointer->SetRenderState(D3DRS_AMBIENT, saved_ambient);

	// ---------------------

	// End Direct3D scene
	device_pointer->EndScene();

	// FOR TESTING
	// D3DXSaveSurfaceToFile(_T("C:\\select_surface.bmp"), D3DXIFF_BMP, select_surface, 0, 0);

	// Get color key surface data into memory
	if(FAILED(device_pointer->GetRenderTargetData(select_surface, select_memory_surface)))
	{	return FALSE;
	}

	return TRUE;
}

// Select a node from the index encoded color select surface - index_out is -1 on no node selected
BOOL select_node(IDirect3DDevice9* device_pointer, const CRect &d3d_window_client_rect, const CPoint& mouse_point, int& index_out)
{
	// D3D Color Struct
	struct d3d_color_s
	{	unsigned char B, G, R, A;
	};

	// Assertions
	_ASSERT(device_pointer != 0);
	_ASSERT(select_memory_surface != 0);

	// Local data
	D3DLOCKED_RECT			locked_rect;
	unsigned char*			pixel_array;
	d3d_color_s				pixel;


	// Set default
	index_out = -1;

	// Lock the memory surface
	if(FAILED(select_memory_surface->LockRect(&locked_rect, &d3d_window_client_rect, D3DLOCK_READONLY)))
	{	return FALSE;
	}

	// Pointer to data is LR.pBits, each row is
    // LR.Pitch bytes apart (often it is the same as width*bpp, but
    // can be larger if driver uses padding)

	// Get the pixel
	pixel_array = static_cast<unsigned char*>(locked_rect.pBits);	
	memcpy(&pixel, pixel_array + ((mouse_point.y * locked_rect.Pitch) + mouse_point.x * sizeof(d3d_color_s)), sizeof(d3d_color_s));	

	// Unlock the memory surface
    select_memory_surface->UnlockRect();
	
	// If pixel is not black then we clicked a node
	if(pixel.R != 0 || pixel.G != 0 || pixel.B != 0)
	{	
		// Get index
		index_out = ((pixel.R * 65536) + (pixel.G * 256) + pixel.B) - 1;
	}

	return TRUE;
}