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VBE.C
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#include <stdio.h>
#include "vbe.h"
uint32_t vbe_selseg = 0;
/*
* uint32_t dpmi_AllocRealSeg( p_size )
*
* Purpose:
* Allocates p_size bytes of low memory,
* padded to a 16 byte boundary.
*
* Returns:
* 0 on error
* ((PMSelector << 16) | RMSegment) on success
*/
uint32_t dpmi_AllocRealSeg( uint32_t p_size );
#pragma aux dpmi_AllocRealSeg=\
" test ebx, ebx"\
" jz AllocRealSeg_Error"\
" cmp ebx, 65535"\
" ja AllocRealSeg_Error"\
" add ebx, 15"\
" shr ebx, 4"\
" mov eax, 0x100"\
" int 0x31"\
" jc AllocRealSeg_Error"\
" and eax, 0x0000FFFF"\
" shl edx, 16"\
" add eax, edx"\
" jmp AllocRealSeg_Exit"\
"AllocRealSeg_Error:"\
" xor eax, eax"\
"AllocRealSeg_Exit:"\
parm[ebx]\
modify[ebx edx]\
value[eax];
/*
* void dpmi_FreeRealSeg( *p_selseg )
*
* Purpose:
* Releases previously allocated low memory.
*
* Returns:
* Nothing
*
*/
void dpmi_FreeRealSeg( uint32_t* p_selseg );
#pragma aux dpmi_FreeRealSeg=\
" test edi, edi"\
" jz FreeRealSeg_Error"\
" mov edx, [edi]"\
" push edi"\
" shr edx, 16"\
" mov eax, 0x101"\
" int 0x31"\
" pop edi"\
" mov dword ptr [edi], 0"\
"FreeRealSeg_Error:"\
parm[edi]\
modify[eax edx edi];
/*
* int dpmi_SimRealModeInt( p_int, p_rmregs )
*
* Purpose:
* Simulates a Real Mode Interrupt.
*
* Returns:
* 0 on error
* 1 on success
*/
int dpmi_SimRealModeInt( uint8_t p_int, rmiregs_t* p_rmregs );
#pragma aux dpmi_SimRealModeInt=\
" push es"\
" test edi, edi"\
" jz SimRealModeInt_Error"\
" and ebx, 0x000000FF"\
" xor ecx, ecx"\
" mov eax, 0x300"\
" int 0x31"\
" jc SimRealModeInt_Error"\
" mov eax, 1"\
" jmp SimRealModeInt_Exit"\
"SimRealModeInt_Error:"\
" xor eax, eax"\
"SimRealModeInt_Exit:"\
" pop es"\
parm[bl][edi]\
modify[ebx ecx edx edi esi]\
value[eax];
/*
* uint16_t dpmi_AllocSel()
*
* Purpose:
* Allocates one descriptor.
*
* Returns:
* 0 on error
* Selector on success
*/
uint16_t dpmi_AllocSel( void );
#pragma aux dpmi_AllocSel=\
" mov eax, 0"\
" mov ecx, 1"\
" int 0x31"\
" jnc AllocSel_Exit"\
" xor ax, ax"\
"AllocSel_Exit:"\
modify[ecx]\
value[ax];
/*
* void dpmi_FreeSel( *p_sel )
*
* Purpose:
* Releases a descriptor.
*
* Returns:
* Nothing
*/
void dpmi_FreeSel( uint16_t* p_sel );
#pragma aux dpmi_FreeSel=\
" test edi, edi"\
" jz FreeSel_Error"\
" mov bx, [edi]"\
" mov dword ptr [edi], 0"\
" mov eax, 1"\
" int 0x31"\
"FreeSel_Error:"\
parm[edi]\
modify[eax ebx];
/*
* int dpmi_SetSelRights( p_sel, p_rights )
*
* Purpose:
* Modifies access rights and type fields for the
* specified selector.
*
* Returns:
* 0 on error
* 1 on success
*/
int dpmi_SetSelRights( uint16_t p_sel, uint16_t p_rights );
#pragma aux dpmi_SetSelRights=\
" mov eax, 9"\
" int 0x31"\
" mov eax, 0"\
" jc SetSelRights_Error"\
" mov eax, 1"\
"SetSelRights_Error:"\
parm[bx][cx]\
value[eax];
/*
* int dpmi_SetSelBase( p_sel, p_linAddr )
*
* Purpose:
* Sets the base address for the specified selector.
*
* Returns:
* 0 on error
* 1 on success
*/
int dpmi_SetSelBase( uint16_t p_sel, uint32_t p_linAddr );
#pragma aux dpmi_SetSelBase=\
" mov edx, ecx"\
" shr ecx, 16"\
" and edx, 0xFFFF"\
" mov eax, 7"\
" int 0x31"\
" jc SetSelBase_Error"\
" mov eax, 1"\
" jmp SetSelBase_Exit"\
"SetSelBase_Error:"\
" xor eax, eax"\
"SetSelBase_Exit:"\
parm[bx][ecx]\
modify[ecx edx]\
value[eax];
/*
* int dpmi_SetSelLimit( p_sel, p_limit )
*
* Purpose:
* Sets the limit for the specified selector.
*
* Returns:
* 0 on error
* 1 on success
*/
int dpmi_SetSelLimit( uint16_t p_sel, uint32_t p_limit );
#pragma aux dpmi_SetSelLimit=\
" mov edx, ecx"\
" shr ecx, 16"\
" and edx, 0xFFFF"\
" mov eax, 8"\
" int 0x31"\
" jc SetSelLimit_Error"\
" mov eax, 1"\
" jmp SetSelLimit_Exit"\
"SetSelLimit_Error:"\
" xor eax, eax"\
"SetSelLimit_Exit:"\
parm[bx][ecx]\
modify[ecx edx]\
value[eax];
/*
* uint32_t dpmi_MapPhysicalAddress( p_physAddr, p_size )
*
* Purpose:
* Converts a physical address to a linear address.
*
* Returns:
* 0 on error
* Linear Address on success
*/
uint32_t dpmi_MapPhysicalAddress( uint32_t p_physAddr,
uint32_t p_size );
#pragma aux dpmi_MapPhysicalAddress=\
" mov ecx, ebx"\
" mov edi, esi"\
" shr ebx, 16"\
" and ecx, 0xFFFF"\
" shr esi, 16"\
" and edi, 0xFFFF"\
" mov eax, 0x800"\
" int 0x31"\
" jc MapPhysicalAddress_Error"\
" shl ebx, 16"\
" and ecx, 0xFFFF"\
" mov eax, ebx"\
" or eax, ecx"\
" jmp MapPhysicalAddress_Exit"\
"MapPhysicalAddress_Error:"\
" xor eax, eax"\
"MapPhysicalAddress_Exit:"\
parm[ebx][esi]\
modify[ebx ecx edx esi edi]\
value[eax];
/*
* uint32_t dpmi_FreePhysicalAddress( *p_linAddr )
*
* Purpose:
* Releases a previously mapped linear address.
*
* Returns:
* Nothing
*/
void dpmi_FreePhysicalAddress( uint32_t* p_linAddr );
#pragma aux dpmi_FreePhysicalAddress=\
" test edi, edi"\
" jz FreePhysicalAddress_Error"\
" mov bx, [edi + 2]"\
" mov cx, [edi + 0]"\
" mov dword ptr [edi], 0"\
" mov eax, 0x0801"\
" int 0x31"\
"FreePhysicalAddress_Error:"\
parm[edi]\
modify[eax];
/*
* uint32_t sysRM16ToFlat32( p_RMSegOfs )
*
* Purpose:
* Converts a Real Mode Seg16:Ofs16 address
* into a Flat 32-Bit address.
*
* Returns:
* (Seg16 << 4) + Ofs16
*/
uint32_t sys_RM16ToFlat32( uint32_t p_RMSegOfs );
#pragma aux sys_RM16ToFlat32=\
" mov edx, eax"\
" and eax, 0xFFFF0000"\
" and edx, 0x0000FFFF"\
" shr eax, 12"\
" add eax, edx"\
parm[eax]\
modify[edx]\
value[eax];
/*
* int vbe_Init()
*
* Purpose:
* Allocates low memory for VBE driver info, low memory
* for VBE mode info, and tests for VBE 2.0+.
*
* Returns:
* 0 on error
* 1 on success
*/
int vbe_Init( void )
{
VBEDriverInfo_t l_drv;
if( vbe_selseg == 0 )
{
vbe_selseg = dpmi_AllocRealSeg(2048);
}
// Indirect revalidation of vbe_selseg
return vbe_GetDriverInfo(&l_drv);
}
/*
* void vbe_Done( **p_ctx )
*
* Purpose:
* Releases low memory, releases system resources used
* by VBE Context, and resets display mode.
*
* Returns:
* Nothing
*/
void vbe_Done( vbectx_t** p_ctx )
{
// Already checks for/sets to NULL
vbe_CloseMode( p_ctx );
// Already checks for/sets to NULL
dpmi_FreeRealSeg( &vbe_selseg );
}
/*
* int vbe_GetDriverInfo( *p_drvInfo )
*
* Purpose:
* Returns VBE driver info. Handles low memory.
* Validates for version VBE 2.0+.
*
* Returns:
* 0 on error
* 1 on success
*/
int vbe_GetDriverInfo( VBEDriverInfo_t* p_drvInfo )
{
char l_vbe2Sig[4] = "VBE2";
rmiregs_t l_regs;
VBEDriverInfo_t* l_di;
char l_drvName[128];
if( vbe_selseg && p_drvInfo )
{
// 2K DOS memory is divided in half. First half is for driver info.
l_di = (VBEDriverInfo_t*)((vbe_selseg & 0x0000FFFF) << 4);
memset( l_di, 0, 1024 );
memcpy( l_di, l_vbe2Sig, 4 );
memset( &l_regs, 0, sizeof(l_regs) );
l_regs.eax = 0x4F00;
l_regs.es = (uint16_t)vbe_selseg;
l_regs.edi = 0;
dpmi_SimRealModeInt( 0x10, &l_regs );
if( (((uint16_t)l_regs.eax) == 0x004F) &&
(strncmp(l_di->VBESignature, "VESA", 4) == 0) &&
(l_di->VBEVersion >= 0x200) )
{
l_di->OEMStringPtr =
sys_RM16ToFlat32(l_di->OEMStringPtr);
l_di->VideoModePtr =
sys_RM16ToFlat32(l_di->VideoModePtr);
l_di->OemVendorNamePtr =
sys_RM16ToFlat32(l_di->OemVendorNamePtr);
l_di->OemProductNamePtr =
sys_RM16ToFlat32(l_di->OemProductNamePtr);
l_di->OemProductRevPtr =
sys_RM16ToFlat32(l_di->OemProductRevPtr);
memcpy( p_drvInfo, l_di, sizeof(VBEDriverInfo_t) );
return 1;
}
}
return 0;
}
/*
* int vbe_GetModeInfo( p_mode, *p_modeInfo )
*
* Purpose:
* Returns specified VBE mode info. Handles low memory.
* Validates for LFB and 8/15/16/24/32-BPP.
*
* Returns:
* 0 on error
* 1 on success
*/
int vbe_GetModeInfo( uint16_t p_mode, VBEModeInfo_t* p_modeInfo )
{
rmiregs_t l_regs;
VBEModeInfo_t* l_mi;
if( !(p_mode && vbe_selseg && p_modeInfo) )
{
return 0;
}
// Check if mode list terminator was passed as parameter
if( p_mode == 0xFFFF )
{
return 0;
}
// 2K DOS memory is divided in half. Second half is for mode info.
l_mi = (VBEModeInfo_t*)(((vbe_selseg & 0x0000FFFF) << 4) + 1024);
memset( l_mi, 0, 1024 );
memset( &l_regs, 0, sizeof(l_regs) );
l_regs.eax = 0x4F01;
l_regs.ecx = p_mode;
l_regs.es = (uint16_t)vbe_selseg;
l_regs.edi = 1024;
dpmi_SimRealModeInt( 0x10, &l_regs );
if( ((uint16_t)l_regs.eax) != 0x004F )
{
return 0;
}
// Mode must be supported
if( (l_mi->ModeAttributes & VBE_MA_MODEHW) == 0 )
{
return 0;
}
// LFB must be present
if( (l_mi->ModeAttributes & VBE_MA_HASLFB) == 0 )
{
return 0;
}
memcpy( p_modeInfo, l_mi, sizeof(VBEModeInfo_t) );
return 1;
}
/*
* uint16_t vbe_FindMode( p_width, p_height, p_bpp )
*
* Purpose:
* Searches VBE Driver mode list for a specific
* VBE or OEM LFB mode. BPP must be an exact match.
* Ignores banked display modes.
*
* Returns:
* 0 on error
* VBE or OEM mode on success
*/
uint16_t vbe_FindMode( uint32_t p_width, uint32_t p_height,
uint8_t p_bpp )
{
VBEDriverInfo_t l_drv;
VBEModeInfo_t l_mi;
uint16_t* l_modeList;
uint16_t l_mode;
// Requested width, height, and BPP must not be 0
if( !(p_width && p_height && p_bpp) )
{
return 0;
}
// Get fresh copy of VBE driver info
if( vbe_GetDriverInfo(&l_drv) == 0 )
{
return 0;
}
// Set and validate mode list pointer
l_modeList = (uint16_t*)l_drv.VideoModePtr;
if( l_modeList == NULL )
{
return 0;
}
// Get first mode
l_mode = *l_modeList;
// Loop through all modes. Stop on first exact match.
while( l_mode != 0xFFFF )
{
// Get next mode
l_mode = *l_modeList;
// Initialize mode information
memset( &l_mi, 0, sizeof(l_mi) );
// Ignore return result since defaults are 0
vbe_GetModeInfo( l_mode, &l_mi );
// If exact match...
if( (l_mi.XResolution == p_width) &&
(l_mi.YResolution == p_height) &&
(l_mi.BitsPerPixel == p_bpp) )
{
// ...then return the display mode
return l_mode;
}
l_modeList++;
}
return 0;
}
/*
* uint16_t vbe_NearestMode( p_width, p_height, p_bpp )
*
* Purpose:
* Searches VBE Driver mode list for a VBE or OEM LFB mode
* at or above the requested width, height, and BPP.
* BPP must be an exact match.
* Ignores banked display modes.
*
* Returns:
* 0 on error
* VBE or OEM mode on success
*/
uint16_t vbe_NearestMode( uint32_t p_width, uint32_t p_height,
uint8_t p_bpp )
{
return 0;
}
/*
* vbectx_t* vbe_SetMode( p_mode )
*
* Purpose:
* Sets the display mode to specified VBE LFB display mode.
* Ignores banked display modes.
*
* Returns:
* NULL on error
* VBE Context on success
*/
vbectx_t* vbe_SetMode( uint16_t p_mode )
{
rmiregs_t l_regs;
vbectx_t* l_ctx;
VBEModeInfo_t l_mi;
uint32_t l_size;
// Already validates Mode and LFB support
memset( &l_mi, 0, sizeof(l_mi) );
if( vbe_GetModeInfo(p_mode, &l_mi) == 0 )
{
return NULL;
}
l_ctx = NULL;
switch( l_mi.BitsPerPixel )
{
case 8:
// EXTRA: Set default palette, and fall through
case 15:
case 16:
case 24:
case 32:
if( l_mi.PhysBasePtr )
{
l_ctx = (vbectx_t*)calloc(1, sizeof(VBEModeInfo_t));
}
break;
default:
// Unsupported video mode
return NULL;
}
if( l_ctx == NULL )
{
return NULL;
}
// Set VBE display mode
memset( &l_regs, 0, sizeof(l_regs) );
l_regs.eax = 0x4F02;
l_regs.ebx = p_mode | 0x4000; // 0x4000 = LFB flag
dpmi_SimRealModeInt( 0x10, &l_regs );
if( ((uint16_t)l_regs.eax) != 0x004F )
{
vbe_ReleaseCtx( &l_ctx );
return NULL;
}
// Allocate LFB selector
l_ctx->lfbsel = dpmi_AllocSel();
if( l_ctx->lfbsel == 0 )
{
vbe_ReleaseCtx( &l_ctx );
return NULL;
}
if( dpmi_SetSelRights(l_ctx->lfbsel, 0x8092) == 0 )
{
vbe_ReleaseCtx( &l_ctx );
return NULL;
}
// Map Linear Frame Buffer
l_size = l_mi.YResolution * l_mi.BytesPerScanline;
l_ctx->lfb = (uint8_t*)dpmi_MapPhysicalAddress(
l_mi.PhysBasePtr, l_size);
if( l_ctx->lfb == NULL )
{
vbe_ReleaseCtx( &l_ctx );
return NULL;
}
// Initialize LFB selector
if( dpmi_SetSelBase(l_ctx->lfbsel, (uint32_t)l_ctx->lfb) == 0 )
{
vbe_ReleaseCtx( &l_ctx );
return NULL;
}
if( dpmi_SetSelLimit(l_ctx->lfbsel, l_size) == 0 )
{
vbe_ReleaseCtx( &l_ctx );
return NULL;
}
// Initialize context with required information
l_ctx->lfbsize = l_size;
l_ctx->bpp = l_mi.BitsPerPixel;
l_ctx->clip.minx = 0;
l_ctx->clip.miny = 0;
l_ctx->clip.maxx = (l_mi.XResolution - 1);
l_ctx->clip.maxy = (l_mi.YResolution - 1);
l_ctx->width = l_mi.XResolution;
l_ctx->height = l_mi.YResolution;
l_ctx->linesize = l_mi.BytesPerScanline;
if( l_mi.MemoryModel == VBE_MM_DCOLOR )
{
l_ctx->rmask = ((1UL << l_mi.RedMaskSize) - 1)
<< l_mi.RedFieldPosition;
l_ctx->gmask = ((1UL << l_mi.GreenMaskSize) - 1)
<< l_mi.GreenFieldPosition;
l_ctx->bmask = ((1UL << l_mi.BlueMaskSize) - 1)
<< l_mi.BlueFieldPosition;
l_ctx->amask = ((1UL << l_mi.RsvdMaskSize) - 1)
<< l_mi.RsvdFieldPosition;
l_ctx->rshift = 8 - l_mi.RedMaskSize;
l_ctx->gshift = 8 - l_mi.GreenMaskSize;
l_ctx->bshift = 8 - l_mi.BlueMaskSize;
l_ctx->ashift = 8 - l_mi.RsvdMaskSize;
l_ctx->rpos = l_mi.RedFieldPosition;
l_ctx->gpos = l_mi.GreenFieldPosition;
l_ctx->bpos = l_mi.BlueFieldPosition;
l_ctx->apos = l_mi.RsvdFieldPosition;
}
return l_ctx;
}
/*
* void vbe_ReleaseCtx( **p_ctx )
*
* Purpose:
* Releases any/all system resources.
*
* Returns:
* Nothing
*/
void vbe_ReleaseCtx( vbectx_t** p_ctx )
{
vbectx_t* l_ctx;
if( p_ctx )
{
l_ctx = *p_ctx;
if( l_ctx )
{
if( l_ctx->lfbsel )
{
dpmi_FreePhysicalAddress( (uint32_t*)&(l_ctx->lfb) );
dpmi_FreeSel( &(l_ctx->lfbsel) );
}
else
{
free( l_ctx->lfb );
}
free( *p_ctx );
}
*p_ctx = NULL;
}
}
/*
* void vbe_CloseMode( **p_ctx )
*
* Purpose:
* Releases system resources, and resets display mode.
*
* Returns:
* Nothing
*/
void vbe_CloseMode( vbectx_t** p_ctx )
{
rmiregs_t l_regs;
if( p_ctx )
{
if( (*p_ctx)->lfbsel )
{
memset( &l_regs, 0, sizeof(l_regs) );
l_regs.eax = 0x03;
dpmi_SimRealModeInt( 0x10, &l_regs );
}
vbe_ReleaseCtx( p_ctx );
}
}
/*
* vbectx_t* vbe_CreateBuf( *p_ctx, p_width, p_height )
*
* Purpose:
* Allocates an off-screen buffer context.
*
* Returns:
* NULL on error
* Valid Off-screen Context on success
*/
vbectx_t* vbe_CreateBuf( vbectx_t* p_ctx,
uint32_t p_width, uint32_t p_height )
{
vbectx_t* l_newctx;
if( p_ctx )
{
l_newctx = (vbectx_t*)malloc(sizeof(vbectx_t));
if( l_newctx )
{
memcpy( l_newctx, p_ctx, sizeof(vbectx_t) );
if( p_width )
{
l_newctx->width = p_width;
}
if( p_height )
{
l_newctx->height = p_height;
}
l_newctx->lfbsel = 0;
l_newctx->clip.minx = 0;
l_newctx->clip.miny = 0;
l_newctx->clip.maxx = (l_newctx->width - 1);
l_newctx->clip.maxy = (l_newctx->height - 1);
l_newctx->lfbsize = l_newctx->height * l_newctx->linesize;
l_newctx->lfb = (uint8_t*)calloc(1, l_newctx->lfbsize);
if( l_newctx->lfb )
{
return l_newctx;
}
free( l_newctx );
}
}
return NULL;
}
/*
* void vbe_SetClip( *p_ctx, p_minx, p_miny, p_maxx, p_maxy )
*
* Purpose:
* Sets requested drawing rectangle to within valid
* boundaries: from (0, 0) to (width - 1, height - 1).
*
* Returns:
* Nothing
*/
void vbe_SetClip( vbectx_t* p_ctx, int32_t p_minx,
int32_t p_miny, int32_t p_maxx, int32_t p_maxy )
{
if( p_ctx )
{
// Validate minx
if( p_minx < 0 )
{
p_minx = 0;
}
// Validate miny
if( p_miny < 0 )
{
p_miny = 0;
}
// Validate maxx
if( p_maxx >= p_ctx->width )
{
p_maxx = p_ctx->width - 1;
}
// Validate maxy
if( p_maxy >= p_ctx->height )
{
p_maxy = p_ctx->height - 1;
}
// Update context clip boundaries
p_ctx->clip.minx = p_minx;
p_ctx->clip.miny = p_miny;
p_ctx->clip.maxx = p_maxx;
p_ctx->clip.maxy = p_maxy;
}
}
/*
* void vbe_Capture( *p_display, *p_buf )
*
* Purpose:
* Copies display to off-screen buffer.
*
* Returns:
* Nothing
*/
void vbe_Capture( vbectx_t* p_display, vbectx_t* p_buf )
{
if( p_display && p_buf )
{
if( p_display->lfb && p_buf->lfb
&& (p_display->lfbsize == p_buf->lfbsize) )
{
memcpy( p_buf->lfb, p_display->lfb, p_buf->lfbsize );
}
}
}
/*
* void vbe_Flip( *p_display, *p_buf )
*
* Purpose:
* Copies off-screen buffer to display.
*
* Returns:
* Nothing
*/
void vbe_Flip( vbectx_t* p_display, vbectx_t* p_buf )
{
if( p_display && p_buf )
{
if( p_display->lfb && p_buf->lfb
&& (p_display->lfbsize == p_buf->lfbsize) )
{
memcpy( p_display->lfb, p_buf->lfb, p_display->lfbsize );
}
}
}
/*
* void vbe_DecodePixel( *p_ctx, p_pixel, *p_r, *p_g, *p_b )
*
* Purpose:
* Converts 32-Bit pixel into R, G, B triplet.
* Intended for 15/16/24/32-BPP, 8-BPP needs a palette.
*
* Returns:
* Nothing
*/
void vbe_DecodePixel( vbectx_t* p_ctx, uint32_t p_pixel,
uint8_t* p_r, uint8_t* p_g, uint8_t* p_b )
{
if( p_ctx && p_r && p_g && p_b )
{
*p_r = ((p_pixel & p_ctx->rmask) >> p_ctx->rpos) << p_ctx->rshift;
*p_g = ((p_pixel & p_ctx->gmask) >> p_ctx->gpos) << p_ctx->gshift;
*p_b = ((p_pixel & p_ctx->bmask) >> p_ctx->bpos) << p_ctx->bshift;
}
}
/*
* uint32_t vbe_EncodePixel( *p_ctx, p_r, p_g, p_b )
*
* Purpose:
* Encodes R, G, B triplet into generic 32-bit pixel format.
* Intended for 15/16/24/32-BPP. 8-BPP needs color matching.
*
* Returns:
* Encoded pixel on success
*/
uint32_t vbe_EncodePixel( vbectx_t* p_ctx,
uint8_t p_r, uint8_t p_g, uint8_t p_b )
{
uint32_t l_r;
uint32_t l_g;
uint32_t l_b;
if( p_ctx )
{
l_r = ((p_r >> p_ctx->rshift) << p_ctx->rpos) & p_ctx->rmask;
l_g = ((p_g >> p_ctx->gshift) << p_ctx->gpos) & p_ctx->gmask;
l_b = ((p_b >> p_ctx->bshift) << p_ctx->bpos) & p_ctx->bmask;
return (l_r | l_g | l_b);
}
return 0;
}
/*
* void vbe_GetPal( *p_ctx, *p_pal );
*
* Purpose:
* Copies hardware palette into an array of R,G,B,A values.
*
* Returns:
* Nothing
*/
void vbe_GetPalASM( rgba_t* p_pal );
#pragma aux vbe_GetPalASM=\
" test edi, edi"\
" jz GetPal_Error"\
""\
" mov dx, 0x3C7"\
" xor al, al"\
" mov ecx, 256"\
" out dx, al"\
""\
" mov dx, 0x3C9"\
""\
"GetPal_Loop:"\
" in al, dx"\
" shl al, 2"\
" mov [edi], al"\
" inc edi"\
""\
" in al, dx"\
" shl al, 2"\
" mov [edi], al"\
" inc edi"\
""\
" in al, dx"\
" shl al, 2"\
" mov [edi], al"\
" add edi, 2"\
""\
" dec ecx"\
" jnz GetPal_Loop"\
""\
"GetPal_Error:"\
parm[edi]\
modify[eax ecx edx edi];
void vbe_GetPal( vbectx_t* p_ctx, rgba_t* p_pal )
{
if( p_ctx )
{
if( p_ctx->bpp == 8 )
{
vbe_GetPalASM( p_pal );
}
}
}
/*
* void vbe_SetPal( *p_ctx, *p_pal );
*
* Purpose:
* Sets internal palette from an array of R,G,B,A values.
*
* Returns:
* Nothing
*/
void vbe_SetPalASM( rgba_t* p_pal );
#pragma aux vbe_SetPalASM=\
" test esi, esi"\
" jz SetPal_Error"\
""\
" mov dx, 0x3C8"\
" xor al, al"\
" mov ecx, 256"\