swimp.c

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/*
Copyright (C) 1997-2001 Id Software, 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 2 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, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
 
/*
RW_IMP.C
 
This file contains ALL Win32 specific stuff having to do with the
software refresh.  When a port is being made the following functions
must be implemented by the port:
 
SWimp_EndFrame
SWimp_Init
SWimp_SetPalette
SWimp_Shutdown
*/
 
#include "client.h"
 
typedef struct {
    HDC         dibdc;      // DC compatible with DIB section
    HBITMAP     dibsect;    // DIB section
    byte        *pixels;    // DIB base pointer, NOT used directly for rendering!
    HGDIOBJ     prevobj;
} sww_t;
 
static sww_t sww;
 
/*
SWimp_Shutdown
 
System specific graphics subsystem shutdown routine.
Destroys DIB surfaces as appropriate.
*/
void VID_Shutdown(void)
{
    if (sww.dibdc) {
        SelectObject(sww.dibdc, sww.prevobj);
        DeleteDC(sww.dibdc);
    }
 
    if (sww.dibsect) {
        DeleteObject(sww.dibsect);
    }
 
    memset(&sww, 0, sizeof(sww));
 
    Win_Shutdown();
}
 
void SWimp_ModeChanged(void)
{
    BITMAPINFO info;
 
    if (!sww.dibdc) {
        return;
    }
 
    // destroy previous DIB section
    if (sww.dibsect) {
        SelectObject(sww.dibdc, sww.prevobj);
        DeleteObject(sww.dibsect);
    }
 
    // fill in the BITMAPINFO struct
    memset(&info, 0, sizeof(info));
 
    info.bmiHeader.biSize           = sizeof(BITMAPINFOHEADER);
    info.bmiHeader.biWidth          = win.rc.width;
    info.bmiHeader.biHeight         = win.rc.height;
    info.bmiHeader.biPlanes         = 1;
    info.bmiHeader.biCompression    = BI_RGB;
    info.bmiHeader.biBitCount       = 32;
 
    // create the DIB section
    sww.dibsect = CreateDIBSection(win.dc,
                                   &info,
                                   DIB_RGB_COLORS,
                                   (void **)&sww.pixels,
                                   NULL,
                                   0);
 
    if (!sww.dibsect) {
        Com_Error(ERR_FATAL, "DIB_Init: CreateDIBSection failed");
    }
 
    if (info.bmiHeader.biHeight > 0) {
        // bottom up
        win.buffer  = sww.pixels + (win.rc.height - 1) * win.rc.width * 4;
        win.pitch   = -win.rc.width * 4;
    } else {
        // top down
        win.buffer  = sww.pixels;
        win.pitch   = win.rc.width * 4;
    }
 
    // clear the DIB memory buffer
    memset(sww.pixels, 0, win.rc.width * win.rc.height * 4);
 
    sww.prevobj = SelectObject(sww.dibdc, sww.dibsect);
    if (!sww.prevobj) {
        Com_Error(ERR_FATAL, "DIB_Init: SelectObject failed\n");
    }
}
 
 
/*
SWimp_Init
 
This routine is responsible for initializing the implementation
specific stuff in a software rendering subsystem.
*/
qboolean VID_Init(void)
{
    // create the window
    Win_Init();
 
    // set display mode
    Win_SetMode();
 
    // create logical DC
    sww.dibdc = CreateCompatibleDC(win.dc);
    if (!sww.dibdc) {
        Com_EPrintf("DIB_Init: CreateCompatibleDC failed with error %lu\n", GetLastError());
        Win_Shutdown();
        return qfalse;
    }
 
    // call SWimp_ModeChanged and friends
    Win_ModeChanged();
    return qtrue;
}
 
void VID_VideoWait(void)
{
}
 
qboolean VID_VideoSync(void)
{
    return qtrue;
}
 
void VID_BeginFrame(void)
{
}
 
/*
SWimp_EndFrame
 
This does an implementation specific copy from the backbuffer to the
front buffer.  In the Win32 case it uses BitBlt if we're using DIB sections/GDI.
*/
void VID_EndFrame(void)
{
    BitBlt(win.dc, 0, 0, win.rc.width, win.rc.height, sww.dibdc, 0, 0, SRCCOPY);
}