/*
** Command & Conquer Red Alert(tm)
** Copyright 2025 Electronic Arts Inc.
**
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU General Public License as published by
** the Free Software Foundation, either version 3 of the License, or
** (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
** GNU General Public License for more details.
**
** You should have received a copy of the GNU General Public License
** along with this program. If not, see .
*/
/***************************************************************************
** C O N F I D E N T I A L --- W E S T W O O D A S S O C I A T E S **
***************************************************************************
* *
* Project Name : WWLIB *
* *
* File Name : PALETTE.C *
* *
* Programmer : BILL STOKES *
* *
* Start Date : 6/20/91 *
* *
* Last Update : August 2, 1994 [SKB] *
* *
*-------------------------------------------------------------------------*
* Note: This module contains dependencies upon the video system, *
* specifically Get_Video_Mode(). *
*-------------------------------------------------------------------------*
* Functions: *
* Set_Palette -- sets the current palette *
* Set_Palette_Color -- Set a color number in a palette to the data. *
* Fade_Palette_To -- Fades the current palette into another *
* Determine_Bump_Rate -- determines desired bump rate for fading *
* Bump_Palette -- increments the palette one step, for fading *
* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
/*
********************************* Includes **********************************
*/
#include
#include "wwstd.h"
#include "video.h"
#include "palette.h"
#include "timer.h"
/*
********************************* Constants *********************************
*/
/*
********************************** Globals **********************************
*/
extern "C" extern UBYTE CurrentPalette[]; /* in pal.asm */
/*
******************************** Prototypes *********************************
*/
PRIVATE VOID cdecl Determine_Bump_Rate(VOID *palette, WORD delay, WORD *ticks, WORD *rate);
PRIVATE BOOL cdecl Bump_Palette(VOID *palette1, UWORD step);
/*
******************************** Code *********************************
*/
/***************************************************************************
* Set_Palette -- sets the current palette *
* *
* INPUT: *
* VOID *palette - palette to set *
* *
* OUTPUT: *
* none *
* *
* WARNINGS: *
* *
* HISTORY: *
* 04/25/1994 SKB : Created. *
* 04/27/1994 BR : Converted to 32-bit *
*=========================================================================*/
VOID cdecl Set_Palette(VOID *palette)
{
#if(IBM)
Set_Palette_Range(palette);
#else
Copy_Palette(palette,CurrentPalette);
LoadRGB4(&Main_Screen->ViewPort,palette,32L);
LoadRGB4(AltVPort,palette,32L);
#endif
} /* end of Set_Palette */
/***************************************************************************
* Set_Palette_Color -- Set a color number in a palette to the data. *
* *
* *
* INPUT: *
* VOID *palette - palette to set color in *
* WORD color - which color index to set *
* VOID *data - RGB data for color *
* *
* OUTPUT: *
* none *
* *
* WARNINGS: *
* *
* HISTORY: *
* 04/25/1994 SKB : Created. *
* 04/27/1994 BR : Converted to 32-bit *
*=========================================================================*/
VOID cdecl Set_Palette_Color(VOID *palette, WORD color, VOID *data)
{
/*
---------------------- Return if 'palette' is NULL -----------------------
*/
if (!palette) return;
/*
------------------- Change the color & set the palette -------------------
*/
#if(IBM)
memcpy(&((UBYTE *)palette)[color * RGB_BYTES], data, RGB_BYTES);
Set_Palette_Range(palette);
#else
palette[color] = *(UWORD*)data;
Set_Palette(palette);
#endif
} /* end of Set_Palette */
/***************************************************************************
* Fade_Palette_To -- Fades the current palette into another *
* *
* This will allow the palette to fade from current palette into the *
* palette that was passed in. This can be used to fade in and fade out. *
* *
* INPUT: *
* BYTE *palette1 - this is the palette to fade to. *
* UWORD delay - fade with this timer count down *
* VOID *callback - user-defined callback function *
* *
* OUTPUT: none *
* *
* WARNINGS: none *
* *
* HISTORY: *
* 06/20/1991 BS : Created. *
*=========================================================================*/
VOID Fade_Palette_To(VOID *palette1, UWORD delay, VOID (*callback)() )
{
BOOL changed; // Flag that palette has changed this tick.
WORD jump; // Gun values to jump per palette set.
ULONG timer; // Tick count timer used for timing.
WORD ticksper; // The ticks (fixed point) per bit jump.
WORD tickaccum;
VOID (*cb_ptr)(VOID); // callback function pointer
// (VOID *)cb_ptr = callback;
cb_ptr = callback;
/*
---------------------- Return if 'palette1' is NULL ----------------------
*/
if (!palette1)
return;
/*
--------------------- Fading only supported in MCGA ----------------------
*/
if (Get_Video_Mode() != MCGA_MODE) { // was global GraphicMode
Set_Palette(palette1);
return;
}
/*
--------------------------- Get the bump rate ----------------------------
*/
Determine_Bump_Rate(palette1, delay, &ticksper, &jump);
tickaccum = 0; // init accumulated elapsed time
timer = TickCount.Time(); // timer = current time
do {
changed = FALSE;
tickaccum += ticksper; // tickaccum = time of next change * 256
timer += (tickaccum >> 8); // timer = time of next change (rounded)
tickaccum &= 0x0FF; // shave off high byte, keep roundoff bits
changed = Bump_Palette(palette1, jump); // increment palette
/*
.................. Wait for time increment to elapse ..................
*/
if (changed) {
while (TickCount.Time() < timer) {
/*
................. Update callback while waiting .................
*/
if (callback) {
#if LIB_EXTERNS_RESOLVED
Sound_Callback(); // should be removed!
#endif
(*cb_ptr)();
}
}
}
#if LIB_EXTERNS_RESOLVED
Sound_Callback(); // should be removed!
#endif
if (callback) {
(*cb_ptr)();
}
} while (changed);
} /* end of Fade_Palette_To */
/***************************************************************************
* Determine_Bump_Rate -- determines desired bump rate for fading *
* *
* INPUT: *
* UBYTE *palette - palette to fade to *
* WORD delay - desired time delay in 60ths of a second *
* WORD *ticks - output: loop ticks per color jump *
* WORD *rate - output: color gun increment rate *
* *
* OUTPUT: *
* none *
* *
* WARNINGS: *
* *
* HISTORY: *
* 04/27/1994 BR : Converted to 32-bit *
* 08/02/1994 SKB : Made private *
*=========================================================================*/
PRIVATE VOID cdecl Determine_Bump_Rate(VOID *palette, WORD delay, WORD *ticks,
WORD *rate)
{
WORD gun1; // Palette 1 gun value.
WORD gun2; // Palette 2 gun value.
WORD diff; // Maximum color gun difference.
WORD tp; // Temporary tick accumulator.
WORD index; // Color gun working index.
LONG t; // Working tick intermediate value.
WORD adiff; // Absolute difference between guns.
/*
------------------------ Find max gun difference -------------------------
*/
diff = 0;
for (index = 0; index < PALETTE_BYTES; index++) {
gun1 = ((UBYTE *)palette)[index];
gun2 = CurrentPalette[index];
adiff = ABS(gun1-gun2);
diff = MAX(diff, adiff);
}
/*------------------------------------------------------------------------
ticks = (total time delay ) / (max gun diff)
The value is computed based on (delay * 256), for fixed-point math;
the lower bits represent the leftover from the division; 'ticks' is
returned still shifted, so the low bits can be used to accumulate the
time more accurately; the caller must shift the accumulated value down
8 bits to determine the actual elapsed time!
------------------------------------------------------------------------*/
t = ((LONG)delay) << 8;
if (diff) {
t /= diff;
t = MIN((long)t, (long)0x7FFF);
}
*ticks = (WORD)t;
/*------------------------------------------------------------------------
Adjust the color gun rate value if the time to fade is faster than can
reasonably be performed given the palette change, ie if (ticks>>8)==0,
and thus less than 1/60 of a second
------------------------------------------------------------------------*/
tp = *ticks;
*rate = 1;
while (*rate <= diff && *ticks < 256) {
*ticks += tp;
*rate += 1;
}
} /* end of Determine_Bump_Rate */
/***************************************************************************
* Bump_Palette -- increments the palette one step, for fading *
* *
* INPUT: *
* palette1 - palette to fade towards *
* step - max step amount, determined by Determine_Bump_Rate *
* *
* OUTPUT: *
* FALSE = no change, TRUE = changed *
* *
* WARNINGS: *
* *
* HISTORY: *
* 04/27/1994 BR : Created. *
* 08/02/1994 SKB : Made private *
*=========================================================================*/
#if(IBM)
PRIVATE BOOL cdecl Bump_Palette(VOID *palette1, UWORD step)
{
BOOL changed=FALSE; // Flag that palette has changed this tick.
WORD index; // Index to DAC register gun.
WORD gun1,gun2; // Palette 1 gun value.
UBYTE palette[PALETTE_BYTES]; // copy of current palette
/*
---------------------- Return if 'palette1' is NULL ----------------------
*/
if (!palette1)
return (FALSE);
/*
--------------------- Fading only supported in MCGA ----------------------
*/
if (Get_Video_Mode() != MCGA_MODE) { // was global GraphicMode
Set_Palette(palette1);
return (FALSE);
}
/*
------------------------ Copy the current palette ------------------------
*/
memcpy(palette, CurrentPalette, 768);
/*
----------------------- Loop through palette bytes -----------------------
*/
for (index = 0; index < PALETTE_BYTES; index++) {
gun1 = ((UBYTE *)palette1)[index];
gun2 = palette[index];
/*
............. If the colors match, go on to the next one ..............
*/
if (gun1 == gun2) continue;
changed = TRUE;
/*
.................. Increment current palette's color ..................
*/
if (gun2 < gun1) {
gun2 += step;
gun2 = MIN(gun2, gun1); // make sure we didn't overshoot it
}
/*
.................. Decrement current palette's color ..................
*/
else {
gun2 -= step;
gun2 = MAX(gun2, gun1); // make sure we didn't overshoot it
}
palette[index] = gun2;
}
/*
----------------- Set current palette to the new palette -----------------
*/
if (changed) {
Set_Palette(&palette[0]);
}
return (changed);
} /* end of Bump_Palette */
#else
/* This is already implemented in asm on the Amiga */
#endif
/**************************** End of palette.cpp ***************************/