// ---------------------------------------------------------------------------
//  Project:  NintendoWare
//  File:     UserRenderCommandShader.vsh
//
//  Copyright (C)2009-2011 Nintendo Co., Ltd.  All rights reserved.
//
//  These coded instructions, statements, and computer programs contain
//  proprietary information of Nintendo of America Inc. and/or Nintendo
//  Company Ltd., and are protected by Federal copyright law.  They may
//  not be disclosed to third parties or copied or duplicated in any form,
//  in whole or in part, without the prior written consent of Nintendo.
//
//  $Revision:$
// ---------------------------------------------------------------------------


// Input registers map
#define InputPos        v0
#define InputColor      v1
#define InputNormal     v2

// Output registers map
#define OutputPosition         o0
#define OutputColor            o1
#define OutputQuaternion       o2
#define OutputView             o3

// Constant registers map
#define WRLD_MAT            c8
#define PROJ_MAT            c86
#define VIEW_MAT            c90

#define TEMP_VEC1           r10
#define TEMP_VEC2           r11
#define TEMP_SRC_Z          r12
#define TEMP_QUATE          r13
#define TEMP_POS            r14
#define TEMP_VIEW           r15

#define ConstVec            c93
#define ConstZero           ConstVec.xxxx
#define ConstHalf           ConstVec.yyyy
#define ConstOne            ConstVec.zzzz
#define ConstInit           ConstVec.xxxz

// Constant registers
def     ConstVec,           0.0, 0.5, 1.0, 3.0

// uniform
#pragma bind_symbol(world,    c8, c10)

// 以下の 2 つのユニフォームは NintendoWare のレジスタ番号と一致させる必要があります
#pragma bind_symbol(proj,    c86, c89)
#pragma bind_symbol(view,    c90, c92)

// input
#pragma bind_symbol(Position.xyz,   v0,v0)
#pragma bind_symbol(Color.xyzw,     v1,v1)
#pragma bind_symbol(Normal,         v2,v2)

// output
#pragma output_map (position,   o0)
#pragma output_map (color,      o1)
#pragma output_map (quaternion, o2 )
#pragma output_map (view,       o3 )

main:
    mov     TEMP_POS,           ConstInit
    mov     TEMP_VIEW,          ConstInit
    mov     TEMP_POS.xyz,       InputPos.xyz
    m4x3    TEMP_VIEW.xyz,      TEMP_POS,           WRLD_MAT
    m4x3    TEMP_POS.xyz,       TEMP_VIEW,          VIEW_MAT
    m4x4    OutputPosition,     TEMP_POS,           PROJ_MAT
    mov     OutputView,        -TEMP_POS

    m3x3    TEMP_VIEW.xyz,      InputNormal,        WRLD_MAT
    m3x3    TEMP_SRC_Z.xyz,     TEMP_VIEW.xyz,      VIEW_MAT            
    
    mov     OutputColor,        InputColor

    dp3     r0.x,               TEMP_SRC_Z,      TEMP_SRC_Z
    rsq     r0.x,               r0.x
    mul     TEMP_SRC_Z.xyz,     TEMP_SRC_Z.xyz,  r0.x

    mov     TEMP_QUATE,         ConstZero
    cmp     0,   0,             TEMP_SRC_Z.z,      -ConstOne        // z == -1.0
    ifc 0, 1, 2
        add     TEMP_VEC1,      TEMP_SRC_Z.z,       ConstOne        // normal.z + 1.0
        mul     TEMP_VEC1,      TEMP_VEC1,          ConstHalf       // 0.5 * (normal.z + 1.0)
        rsq     TEMP_VEC1,      TEMP_VEC1.z                         // 1 / sqrt(0.5*(normal.z + 1.0))
        mul     TEMP_VEC2.xy,   TEMP_SRC_Z,         ConstHalf       // 0.5 * normal
        rcp     TEMP_QUATE.z,   TEMP_VEC1.z                         // sqrt(0.5*(normal.z + 1.0))
        mul     TEMP_QUATE.xy,  TEMP_VEC2.xy,       TEMP_VEC1.x     // 0.5*normal / quaternion.z （クォータニオンからの展開時にきちんと、nrm = (mtx.31, mtx.32, mtx33) になる）
    else
        mov     TEMP_QUATE.x,   ConstOne                            // これで展開時に 0, 0, -1 になる
    endif

    mov    OutputQuaternion,       TEMP_QUATE
    end
endmain: