189 lines
4.8 KiB
C++
189 lines
4.8 KiB
C++
/*
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** Command & Conquer Red Alert(tm)
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** Copyright 2025 Electronic Arts Inc.
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**
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** This program is free software: you can redistribute it and/or modify
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** it under the terms of the GNU General Public License as published by
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** the Free Software Foundation, either version 3 of the License, or
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** (at your option) any later version.
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**
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** This program is distributed in the hope that it will be useful,
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** but WITHOUT ANY WARRANTY; without even the implied warranty of
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** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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** GNU General Public License for more details.
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**
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** You should have received a copy of the GNU General Public License
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** along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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/****************************************************************************
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*
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* C O N F I D E N T I A L -- W E S T W O O D S T U D I O S
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*
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*----------------------------------------------------------------------------
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*
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* PROJECT
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* VQAPlay32 library.
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*
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* FILE
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* dstream.c
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*
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* DESCRIPTION
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* DOS IO handler.
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*
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* PROGRAMMER
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* Denzil E. Long, Jr.
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*
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* DATE
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* April 10, 1995
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*
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*----------------------------------------------------------------------------
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*
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* PUBLIC
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* VQA_InitAsDOS - Initialize IO with the standard DOS handler.
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*
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* PRIVATE
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* VQADOSHandler - Standard DOS IO handler.
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*
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****************************************************************************/
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#include <fcntl.h>
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#include <io.h>
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#include "vqaplayp.h"
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/*---------------------------------------------------------------------------
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* PRIVATE DECLARATIONS
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*-------------------------------------------------------------------------*/
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static long VQADOSHandler(VQAHandle *vqa, long action, void *buffer,
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long nbytes);
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/****************************************************************************
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*
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* NAME
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* VQA_InitAsDOS - Initialize IO with the standard DOS handler.
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*
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* SYNOPSIS
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* VQA_InitAsDOS(VQA)
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*
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* VQA_InitAsDOS(VQAHandle *);
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*
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* FUNCTION
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* Initialize the IO of the specified handle as a standard DOS access.
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*
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* INPUTS
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* VQA - Pointer to VQAHandle to initialize as DOS.
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*
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* RESULT
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* NONE
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*
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****************************************************************************/
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void VQA_InitAsDOS(VQAHandle *vqa)
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{
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((VQAHandleP *)vqa)->IOHandler = VQADOSHandler;
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}
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/****************************************************************************
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*
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* NAME
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* VQADOSHandler - Standard DOS IO handler.
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*
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* SYNOPSIS
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* Error = VQADOSHandler(VQA, Action, Buffer, NBytes)
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*
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* unsigned long VQADOSHandler(VQAHandle *, long, long, long);
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*
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* FUNCTION
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* Perform the requested action on the standard DOS file system.
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*
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* INPUTS
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* VQA - VQAHandle to operate on.
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* Action - Action to perform.
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* Buffer - Buffer to Read/Write to/from.
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* NBytes - Number of bytes to operate on.
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*
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* RESULT
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* Error - 0 if successful, otherwise error.
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*
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****************************************************************************/
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static long VQADOSHandler(VQAHandle *vqa, long action, void *buffer,
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long nbytes)
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{
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long fh;
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long error;
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fh = vqa->VQAio;
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/* Perform the action specified by the IO command */
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switch (action) {
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/* VQACMD_READ means read NBytes and place it in the memory
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* pointed to by Buffer.
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*
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* Any error code returned will be remapped by VQA library into
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* VQAERR_READ.
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*/
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case VQACMD_READ:
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error = (read(fh, buffer, nbytes) != nbytes);
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break;
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/* VQACMD_WRITE is analogous to VQACMD_READ.
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*
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* Writing is not allowed to the VQA file, VQA library will remap the
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* error into VQAERR_WRITE.
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*/
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case VQACMD_WRITE:
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error = 1;
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break;
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/* VQACMD_SEEK asks that you perform a seek relative to the current
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* position. NBytes is a signed number, indicating seek direction
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* (positive for forward, negative for backward). Buffer has no meaning
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* here.
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*
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* Any error code returned will be remapped by VQA library into
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* VQAERR_SEEK.
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*/
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case VQACMD_SEEK:
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error = (lseek(fh, nbytes, (long)buffer) == -1);
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break;
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/* VQACMD_OPEN asks that you open the file for access. */
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case VQACMD_OPEN:
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error = open((char *)buffer, (O_RDONLY|O_BINARY));
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if (error != -1) {
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vqa->VQAio = error;
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error = 0;
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}
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break;
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case VQACMD_CLOSE:
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close(fh);
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error = 0;
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break;
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/* VQACMD_INIT means to prepare your IO for reading. This is used for
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* certain IOs that can't be read immediately upon opening, and need
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* further preparation. This operation is allowed to fail; the error code
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* will be returned directly to the client.
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*/
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case VQACMD_INIT:
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/* IFFCMD_CLEANUP means to terminate the transaction with the associated
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* IO. This is used for IOs that can't simply be closed. This operation
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* is not allowed to fail; any error returned will be ignored.
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*/
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case VQACMD_CLEANUP:
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error = 0;
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break;
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}
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return (error);
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}
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