///////////////////////////////////////////////////////////////////////////////
// Copyright (C) Microsoft Corporation, 2000.
//
// PixRef.cpp
//
// Direct3D Reference Device - Pixel Buffer Referencing
//
///////////////////////////////////////////////////////////////////////////////
#include "pch.cpp"
#pragma hdrstop

extern int g_DXTBlkSize[];

//-----------------------------------------------------------------------------
//
// PixelAddress - Form character address of locations within buffers using base
// pointer, pitch and type.
//
//-----------------------------------------------------------------------------

//
// common internal version
//
char*
PixelAddress(
    int iX, int iY, int iZ, int iSample,
    BYTE* pBits, int iYPitch, int iZPitch, int cSamples, RDSurfaceFormat SType )
{
    // initialize return value to start of scan line (pitch is always in bytes)
    BYTE* pPixAddr = pBits + iY*iYPitch + iZ*iZPitch;

    // bump along scan line depending on surface type to point to pixel data
    switch ( SType )
    {
    default:
        _ASSERTf(0, ("Unknown RDSurfaceFormat value %08x", SType));
        return NULL;
    case RD_SF_NULL:
        break;

    case RD_SF_B8G8R8A8:
    case RD_SF_B8G8R8X8:
    case RD_SF_U8V8L8X8:
    case RD_SF_Z24S8:
    case RD_SF_Z24X8:
    case RD_SF_S8Z24:
    case RD_SF_X8Z24:
    case RD_SF_Z24X4S4:
    case RD_SF_X4S4Z24:
    case RD_SF_Z32S0:
    case RD_SF_U8V8W8Q8:
    case RD_SF_U10V11W11:
    case RD_SF_U16V16:
    case RD_SF_R10G10B10A2:
    case RD_SF_R8G8B8A8:
    case RD_SF_R8G8B8X8:
    case RD_SF_R16G16:
    case RD_SF_U11V11W10:
    case RD_SF_U10V10W10A2:
    case RD_SF_U8V8X8A8:
    case RD_SF_U8V8X8L8:
        pPixAddr += (iX*cSamples*4 + iSample*4);
        break;

    case RD_SF_B5G6R5:
    case RD_SF_B5G5R5X1:
    case RD_SF_B5G5R5A1:
    case RD_SF_P8A8:
    case RD_SF_L8A8:
    case RD_SF_U8V8:
    case RD_SF_U5V5L6:
    case RD_SF_Z16S0:
    case RD_SF_Z15S1:
    case RD_SF_S1Z15:
    case RD_SF_B4G4R4A4:
    case RD_SF_B4G4R4X4:
    case RD_SF_YUY2:
    case RD_SF_UYVY:
    case RD_SF_B2G3R3A8:
        pPixAddr += (iX*cSamples*2 + iSample*2);
        break;

    case RD_SF_B8G8R8:
        pPixAddr += (iX*cSamples*3 + iSample*3);
        break;

    case RD_SF_PALETTE8:
    case RD_SF_L8:
    case RD_SF_A8:
    case RD_SF_B2G3R3:
    case RD_SF_L4A4:
        pPixAddr += (iX*cSamples*1 + iSample*1);
        break;

    case RD_SF_PALETTE4:
        pPixAddr += (iX>>1);
        break;

    // For the DXT texture formats, obtain the address of the
    // block from whih to decompress the texel from
    case RD_SF_DXT1:
    case RD_SF_DXT2:
    case RD_SF_DXT3:
    case RD_SF_DXT4:
    case RD_SF_DXT5:
        pPixAddr = pBits + iZ*iZPitch + (iY >> 2)*iYPitch + (iX>>2) *
            g_DXTBlkSize[(int)SType - (int)RD_SF_DXT1];
        break;
    }
    return (char *)pPixAddr;
}

//
// external versions
//
char*
PixelAddress(
    int iX, int iY, int iZ,
    BYTE* pBits, int iYPitch, int iZPitch, RDSurfaceFormat SType )
{
    return PixelAddress( iX, iY, iZ, 0, pBits, iYPitch, iZPitch, 1, SType );
}

char*
PixelAddress(
    int iX, int iY, int iZ, int iSample, RDSurface2D* pRT )
{
    return PixelAddress( iX, iY, iZ, iSample,
        pRT->GetBits(), pRT->GetPitch(), 0 /* pRT->GetSlicePitch() */,
        pRT->GetSamples(), pRT->GetSurfaceFormat() );
}

///////////////////////////////////////////////////////////////////////////////
// end