mgcsoftzc.cpp

3D Game Engine Design Source Code非常棒

// Magic Software, Inc.
// http://www.magic-software.com
// Copyright (c) 2000, All Rights Reserved
//
// Source code from Magic Software is supplied under the terms of a license
// agreement and may not be copied or disclosed except in accordance with the
// terms of that agreement.  The various license agreements may be found at
// the Magic Software web site.  This file is subject to the license
//
// RESTRICTED USE SOURCE CODE
// http://www.magic-software.com/License/restricted.pdf

#include "MgcSoftASM.h"
#include "MgcSoftRenderer.h"

// TO DO.  This sample code ignores the members of the MgcZBufferState
// object.  The depth buffer is always tested and written when necessary.
// The comparison function is 'less than or equal to'.  The code should be
// modified to properly handle the members.

//---------------------------------------------------------------------------
void MgcSoftRenderer::DrawEdgeZC (unsigned int uiV0, unsigned int uiV1)
{
    EdgeSetupParameters
    LinAttrSetup(4)

    MgcColor& rkC0 = m_kMesh.Color(uiV0);
    MgcColor& rkC1 = m_kMesh.Color(uiV1);

    MgcSoftASM_FloatToIntMult(rkC0.r,aiA0[0],8);
    MgcSoftASM_FloatToIntMult(rkC0.g,aiA0[1],8);
    MgcSoftASM_FloatToIntMult(rkC0.b,aiA0[2],8);
    MgcSoftASM_FloatToIntMult(m_kMesh.Depth(uiV0),aiA0[3],16);
    MgcSoftASM_FloatToIntMult(rkC1.r,aiA1[0],8);
    MgcSoftASM_FloatToIntMult(rkC1.g,aiA1[1],8);
    MgcSoftASM_FloatToIntMult(rkC1.b,aiA1[2],8);
    MgcSoftASM_FloatToIntMult(m_kMesh.Depth(uiV1),aiA1[3],16);

    EdgeInitX
    InitLinAttrX
    EdgePrologTraverseX

    if ( aiA0[3] <= m_ausZBuffer[iIndex] )
    {
        m_akBuffer[iIndex] = MgcSoftColor(aiA0[0],aiA0[1],aiA0[2]);
        m_ausZBuffer[iIndex] = aiA0[3];
    }

    EdgeReturnX
    UpdateLinAttrX
    EdgeEpilogTraverseX
    EdgeExitX

    EdgeInitY
    InitLinAttrY
    EdgePrologTraverseY

    if ( aiA0[3] <= m_ausZBuffer[iIndex] )
    {
        m_akBuffer[iIndex] = MgcSoftColor(aiA0[0],aiA0[1],aiA0[2]);
        m_ausZBuffer[iIndex] = aiA0[3];
    }

    EdgeReturnY
    UpdateLinAttrY
    EdgeEpilogTraverseY
    EdgeExitY
}
//---------------------------------------------------------------------------
void MgcSoftRenderer::DrawTriZC (unsigned int uiV0, unsigned int uiV1,
    unsigned int uiV2)
{
    TriangleSetupParameters
    LinAttrSetup(4)

    MgcColor& rkC0 = m_kMesh.Color(uiV0);
    MgcColor& rkC1 = m_kMesh.Color(uiV1);
    MgcColor& rkC2 = m_kMesh.Color(uiV2);
    m_uiNumLinAttr = 4;  // r, g, b, d
    m_uiNumPerAttr = 0;  // none
    m_aafLinAttr[0][0] = rkC0.r;
    m_aafLinAttr[0][1] = rkC0.g;
    m_aafLinAttr[0][2] = rkC0.b;
    m_aafLinAttr[0][3] = m_kMesh.Depth(uiV0);
    m_aafLinAttr[1][0] = rkC1.r;
    m_aafLinAttr[1][1] = rkC1.g;
    m_aafLinAttr[1][2] = rkC1.b;
    m_aafLinAttr[1][3] = m_kMesh.Depth(uiV1);
    m_aafLinAttr[2][0] = rkC2.r;
    m_aafLinAttr[2][1] = rkC2.g;
    m_aafLinAttr[2][2] = rkC2.b;
    m_aafLinAttr[2][3] = m_kMesh.Depth(uiV2);

    TriBeginLoop

    MgcSoftASM_FloatToIntMult(m_aafLinAttrMin[iY][0],aiA0[0],8);
    MgcSoftASM_FloatToIntMult(m_aafLinAttrMin[iY][1],aiA0[1],8);
    MgcSoftASM_FloatToIntMult(m_aafLinAttrMin[iY][2],aiA0[2],8);
    MgcSoftASM_FloatToIntMult(m_aafLinAttrMin[iY][3],aiA0[3],16);
    MgcSoftASM_FloatToIntMult(m_aafLinAttrMax[iY][0],aiA1[0],8);
    MgcSoftASM_FloatToIntMult(m_aafLinAttrMax[iY][1],aiA1[1],8);
    MgcSoftASM_FloatToIntMult(m_aafLinAttrMax[iY][2],aiA1[2],8);
    MgcSoftASM_FloatToIntMult(m_aafLinAttrMax[iY][3],aiA1[3],16);

    if ( iDx > 1 )
    {
        InitLinAttrX
        for (int iX = iX0, iAx = 2*iDx; iX <= iX1; iX++, iIndex++)
        {
            if ( aiA0[3] <= m_ausZBuffer[iIndex] )
            {
                m_akBuffer[iIndex] = MgcSoftColor(aiA0[0],aiA0[1],aiA0[2]);
                m_ausZBuffer[iIndex] = aiA0[3];
            }
            UpdateLinAttrX
        }
    }
    else if ( iDx == 1 )
    {
        if ( aiA0[3] <= m_ausZBuffer[iIndex] )
        {
            m_akBuffer[iIndex] = MgcSoftColor(aiA0[0],aiA0[1],aiA0[2]);
            m_ausZBuffer[iIndex] = aiA0[3];
        }
        iIndex++;

        if ( aiA1[3] <= m_ausZBuffer[iIndex] )
        {
            m_akBuffer[iIndex] = MgcSoftColor(aiA1[0],aiA1[1],aiA1[2]);
            m_ausZBuffer[iIndex] = aiA1[3];
        }
    }
    else
    {
        if ( aiA0[3] <= m_ausZBuffer[iIndex] )
        {
            m_akBuffer[iIndex] = MgcSoftColor(aiA0[0],aiA0[1],aiA0[2]);
            m_ausZBuffer[iIndex] = aiA0[3];
        }
    }

    TriEndLoop
}
//---------------------------------------------------------------------------