mirror of
https://github.com/OpenTrespasser/JurassicParkTrespasser.git
synced 2024-12-20 07:31:56 +00:00
331 lines
8.0 KiB
C++
331 lines
8.0 KiB
C++
/***********************************************************************************************
|
|
*
|
|
* Copyright © DreamWorks Interactive. 1996
|
|
*
|
|
* Contents:
|
|
* Overloaded functions for "Walk.hpp" optimized for the Pentium.
|
|
* Optimized for the AMD K6-3D Processor
|
|
*
|
|
* Bugs:
|
|
*
|
|
* To do:
|
|
* Changed the name of the module to 'TexWalkEx.hpp.' Make functions member functions of
|
|
* CWalk1D and CWalk2D.
|
|
*
|
|
***********************************************************************************************
|
|
*
|
|
* $Log:: /JP2_PC/Source/Lib/Renderer/Primitives/AMDK6/WalkEx.hpp $
|
|
*
|
|
* 4 97.10.27 1:25p Mmouni
|
|
* Initial K6-3D version, copied from the Pentium versions.
|
|
*
|
|
* 8 9/01/97 8:04p Rwyatt
|
|
*
|
|
* 7 8/15/97 2:33a Rwyatt
|
|
* Fixed local variable problem
|
|
*
|
|
* 6 8/15/97 12:58a Rwyatt
|
|
* Removed local floating point constants and used the global ones.
|
|
*
|
|
* 5 1/15/97 1:02p Pkeet
|
|
* Moved the assembly versions of the 2d initializing functions to WalkEx.hpp. Removed fog
|
|
* parameters.
|
|
*
|
|
* 4 8/12/96 7:15p Pkeet
|
|
* Added comments.
|
|
*
|
|
* 3 7/10/96 1:48p Pkeet
|
|
* Added additional comments.
|
|
*
|
|
* 2 7/09/96 6:38p Pkeet
|
|
* Added a '+=' operator for 'CWalk1D.'
|
|
*
|
|
* 1 7/09/96 6:00p Pkeet
|
|
* Initial implementation.
|
|
*
|
|
**********************************************************************************************/
|
|
|
|
#ifndef HEADER_LIB_RENDERER_PRIMITIVES_P5_WALKEX_HPP
|
|
#define HEADER_LIB_RENDERER_PRIMITIVES_P5_WALKEX_HPP
|
|
|
|
// Make sure this file is being included from 'FixedP.hpp'.
|
|
#ifndef HEADER_LIB_RENDERER_PRIMITIVES_WALK_HPP
|
|
#error The header file Walk.hpp has not been included!
|
|
#endif
|
|
|
|
|
|
//
|
|
// Global functions.
|
|
//
|
|
|
|
//*********************************************************************************************
|
|
//
|
|
inline void operator+=(CWalk1D& w1d_a, const CWalk1D& w1d_b)
|
|
//
|
|
// Adds two CWalk1D parameters together and stores the result in the first parameter.
|
|
//
|
|
// Notes:
|
|
// The assembly version is equivalent to the following 'C' code:
|
|
//
|
|
// w1d_a.bfx.i4Int += w1d_b.bfx.i4Int;
|
|
// if (iAddCarry(w1d_a.bfx.u4Frac, w1d_a.bfx.u4Frac, w1d_b.bfx.u4Frac))
|
|
// w1d_a.bfx.i4Int += w1d_a.iOffsetPerLine;
|
|
//
|
|
//**************************************
|
|
{
|
|
//
|
|
// Register usage:
|
|
//
|
|
// Register Variable
|
|
//
|
|
// ebx w1d_a.bfx.u4Frac
|
|
// ecx w1d_b.bfx.i4Int
|
|
// edi w1d_a
|
|
// esi w1d_b
|
|
//
|
|
__asm
|
|
{
|
|
// Load variables into the registers.
|
|
mov edi, w1d_a
|
|
mov esi, w1d_b
|
|
mov ebx, [edi]CWalk1D.bfxValue.u4Frac
|
|
mov ecx, [edi]CWalk1D.bfxValue.i4Int
|
|
|
|
// Add the integer portions together.
|
|
add ecx, [esi]CWalk1D.bfxValue.i4Int
|
|
|
|
//
|
|
// Add the fractional portions together, and add an extra step value if a carry
|
|
// results.
|
|
//
|
|
add ebx, [esi]CWalk1D.bfxValue.u4Frac
|
|
jnc short SKIP_STEP_ADD
|
|
add ecx, [edi]CWalk1D.iOffsetPerLine
|
|
|
|
SKIP_STEP_ADD:
|
|
|
|
// Store the modified variables.
|
|
mov [edi]CWalk1D.bfxValue.u4Frac, ebx
|
|
mov [edi]CWalk1D.bfxValue.i4Int, ecx
|
|
}
|
|
}
|
|
|
|
|
|
//*********************************************************************************************
|
|
//
|
|
inline void operator+=
|
|
(
|
|
CWalk2D& w2d_a, // First 2D walk parameter, cumulative results stored here.
|
|
const CWalk2D& w2d_b // Second 2D walk parameter.
|
|
)
|
|
//
|
|
// Adds two CWalk2D parameters together and stores the result in the first parameter.
|
|
//
|
|
// Notes:
|
|
// This code demonstrates an implementation Michael Abrash's trick of walking through
|
|
// a 2D texture map with arbitrary widths and heights. The assembly version is equivalent
|
|
// to the following 'C' code:
|
|
//
|
|
// int i_carry = iAddCarry(w2d_a.uVFrac, w2d_a.uVFrac, w2d_b.uVFrac);
|
|
// w2d_a.iUVInt[1] += w2d_b.iUVInt[i_carry + 1] - iAddCarry(w2d_a.uUFrac, w2d_a.uUFrac,
|
|
// w2d_b.uUFrac);
|
|
//
|
|
// The algorithm can be described as follows:
|
|
//
|
|
// 1. Add the fractional components of V together, and store the carry in a register.
|
|
//
|
|
// 2. Add the fractional components of U together, and add the carry of the U
|
|
// additions to the integer UV portion.
|
|
//
|
|
// 3. If there was no carry from the V fraction addition, add the combined integer
|
|
// components of U and V. If there was a carry from the V fraction addition, add
|
|
// the combined integer components of U and V plus a value representing the V line
|
|
// offset.
|
|
//
|
|
//**************************************
|
|
{
|
|
//
|
|
// Register usage:
|
|
//
|
|
// Register Variable
|
|
//
|
|
// eax Temporary
|
|
// ebx w2d_a.uUFrac
|
|
// ecx w2d_a.uVFrac
|
|
// edx w2d_a.iUVInt[1]
|
|
// edi w2d_a
|
|
// esi w2d_b
|
|
//
|
|
__asm
|
|
{
|
|
// Load variables into the registers.
|
|
mov edi, w2d_a
|
|
mov esi, w2d_b
|
|
mov ebx, [edi]CWalk2D.uUFrac
|
|
mov ecx, [edi]CWalk2D.uVFrac
|
|
mov edx, [edi + 4]CWalk2D.iUVInt
|
|
|
|
// Add the V fractional values together and store the carry.
|
|
add ecx, [esi]CWalk2D.uVFrac
|
|
sbb eax, eax
|
|
|
|
// Add the U fractional values, setting the carry flag.
|
|
add ebx, [esi]CWalk2D.uUFrac
|
|
|
|
// Add the integer values from the integer table, and add a possible carry.
|
|
adc edx, [esi + eax*4 + 4]CWalk2D.iUVInt
|
|
|
|
// Store the modified variables.
|
|
mov [edi]CWalk2D.uUFrac, ebx
|
|
mov [edi]CWalk2D.uVFrac, ecx
|
|
mov [edi + 4]CWalk2D.iUVInt, edx
|
|
}
|
|
}
|
|
|
|
|
|
#if VER_ASM
|
|
|
|
//*****************************************************************************************
|
|
//
|
|
inline void Initialize
|
|
(
|
|
CWalk2D& rw2d,
|
|
float f_u, // The 'U' component.
|
|
float f_v, // The 'V' component.
|
|
int i_width // The width of the texture map.
|
|
)
|
|
//
|
|
// Sets the fractional and integer parts of the CWalk2D object.
|
|
//
|
|
//**************************************
|
|
{
|
|
const float fFixed16Scale = 65536.0;
|
|
int32 i4_temp;
|
|
|
|
__asm
|
|
{
|
|
mov esi, [rw2d]
|
|
|
|
fld [fFixed16Scale]
|
|
fmul [f_u]
|
|
fistp [i4_temp]
|
|
|
|
fld [fFixed16Scale]
|
|
fmul [f_v]
|
|
mov ecx, [i4_temp]
|
|
|
|
sar ecx, 16
|
|
mov edx, [i4_temp]
|
|
|
|
fistp [i4_temp]
|
|
|
|
shl edx, 16
|
|
mov eax, [i4_temp]
|
|
|
|
sar eax, 16
|
|
mov [esi]CWalk2D.uUFrac, edx
|
|
|
|
imul [i_width]
|
|
mov ebx, [i4_temp]
|
|
|
|
shl ebx, 16
|
|
add eax, ecx
|
|
|
|
mov [esi]CWalk2D.uVFrac, ebx
|
|
mov [esi + 4]CWalk2D.iUVInt, eax
|
|
|
|
add eax, i_width
|
|
mov [esi]CWalk2D.iUVInt, eax
|
|
}
|
|
}
|
|
|
|
|
|
//*****************************************************************************************
|
|
//
|
|
inline void InitializePos
|
|
(
|
|
CWalk2D& rw2d,
|
|
float f_u, // The 'U' component.
|
|
float f_v, // The 'V' component.
|
|
int i_width // The width of the texture map.
|
|
)
|
|
//
|
|
// Sets the fractional and integer parts of the CWalk2D object.
|
|
//
|
|
//**************************************
|
|
{
|
|
#define iBITS_ACCURACY 11
|
|
const float fFastFixed16Conversion = float(1 << (23 - iBITS_ACCURACY));
|
|
int32 i4_temp_a;
|
|
int32 i4_temp_b;
|
|
|
|
__asm
|
|
{
|
|
mov esi, [rw2d]
|
|
|
|
fld [fFastFixed16Conversion]
|
|
fld st(0)
|
|
fadd [f_u]
|
|
fstp float ptr[i4_temp_a]
|
|
mov ecx, [i4_temp_a]
|
|
fadd [f_v]
|
|
|
|
sar ecx, iBITS_ACCURACY
|
|
|
|
fstp [i4_temp_b]
|
|
|
|
and ecx, 0x007FFFFF >> iBITS_ACCURACY
|
|
mov edx, [i4_temp_a]
|
|
|
|
shl edx, 32 - iBITS_ACCURACY
|
|
mov eax, [i4_temp_b]
|
|
|
|
sar eax, iBITS_ACCURACY
|
|
and eax, 0x007FFFFF >> iBITS_ACCURACY
|
|
mov [esi]CWalk2D.uUFrac, edx
|
|
|
|
imul [i_width]
|
|
mov ebx, [i4_temp_b]
|
|
|
|
shl ebx, 32 - iBITS_ACCURACY
|
|
add eax, ecx
|
|
|
|
mov [esi]CWalk2D.uVFrac, ebx
|
|
mov [esi + 4]CWalk2D.iUVInt, eax
|
|
|
|
//add eax, i_width
|
|
//mov [esi]CWalk2D.iUVInt, eax
|
|
}
|
|
}
|
|
|
|
#endif // VER_ASM
|
|
|
|
|
|
//
|
|
// Additional notes.
|
|
//
|
|
|
|
/**********************************************************************************************
|
|
*
|
|
* This function is included only to illustrate how the 'C' versions of the overloaded '+='
|
|
* operators for CWalk1D and CWalk2D classes work. Reference is made in the notes of these
|
|
* respective functions to this 'iAddCarry' function.
|
|
*
|
|
* inline int iAddCarry(uint& u_result, uint i_a, uint i_b)
|
|
* {
|
|
* // Add the two values together.
|
|
* u_result = i_a + i_b;
|
|
*
|
|
* // Return -1 if a carry is present.
|
|
* if ((u_result < i_a) || (u_result < i_b))
|
|
* return -1;
|
|
*
|
|
* // Return 0 if there is no carry.
|
|
* return 0;
|
|
* }
|
|
*
|
|
**********************************************************************************************/
|
|
|
|
|
|
#endif
|