-/*
- * Acess2 Kernel
- * - By John Hodge
- *
- * drvutil.c
- * - Common Driver/Filesystem Helper Functions
- */
-#define DEBUG 0
-#include <acess.h>
-#include <api_drv_disk.h>
-#include <api_drv_video.h>
-
-// === TYPES ===
-
-// === PROTOTYPES ===
-//int DrvUtil_Video_2DStream(void *Ent, void *Buffer, int Length, tDrvUtil_Video_2DHandlers *Handlers, int SizeofHandlers);
-//size_t DrvUtil_Video_WriteLFB(int Mode, tDrvUtil_Video_BufInfo *FBInfo, size_t Offset, size_t Length, void *Src);
-//void DrvUtil_Video_SetCursor(tDrvUtil_Video_BufInfo *Buf, tVideo_IOCtl_Bitmap *Bitmap);
-//void DrvUtil_Video_DrawCursor(tDrvUtil_Video_BufInfo *Buf, int X, int Y);
-void DrvUtil_Video_RenderCursor(tDrvUtil_Video_BufInfo *Buf);
-//void DrvUtil_Video_RemoveCursor(tDrvUtil_Video_BufInfo *Buf);
-void DrvUtil_Video_2D_Fill(void *Ent, Uint16 X, Uint16 Y, Uint16 W, Uint16 H, Uint32 Colour);
-void DrvUtil_Video_2D_Blit(void *Ent, Uint16 DstX, Uint16 DstY, Uint16 SrcX, Uint16 SrcY, Uint16 W, Uint16 H);
-
-// === GLOBALS ===
-tDrvUtil_Video_2DHandlers gDrvUtil_Stub_2DFunctions = {
- NULL,
- DrvUtil_Video_2D_Fill,
- DrvUtil_Video_2D_Blit
-};
-tVideo_IOCtl_Bitmap gDrvUtil_TextModeCursor = {
- 8, 16,
- 0, 0,
- {
- 0, 0, 0 , 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0,-1, 0xFF000000, 0, 0, 0, 0, 0,
- 0, 0, 0 , 0, 0, 0, 0, 0,
- 0, 0, 0 , 0, 0, 0, 0, 0
- }
-};
-
-// === CODE ===
-// --- Video Driver Helpers ---
-int DrvUtil_Video_2DStream(void *Ent, const void *Buffer, int Length,
- tDrvUtil_Video_2DHandlers *Handlers, int SizeofHandlers)
-{
- const Uint8 *stream = Buffer;
- int rem = Length;
- int op;
- while( rem )
- {
- rem --;
- op = *stream;
- stream ++;
-
- if(op > NUM_VIDEO_2DOPS) {
- Log_Warning("DrvUtil",
- "DrvUtil_Video_2DStream: Unknown operation %i",
- op);
- return Length-rem;
- }
-
- if(op*sizeof(void*) > SizeofHandlers) {
- Log_Warning("DrvUtil",
- "DrvUtil_Video_2DStream: Driver does not support op %i",
- op);
- return Length-rem;
- }
-
- switch(op)
- {
- case VIDEO_2DOP_NOP: break;
-
- case VIDEO_2DOP_FILL:
- if(rem < 10) return Length-rem;
-
- if(!Handlers->Fill) {
- Log_Warning("DrvUtil", "DrvUtil_Video_2DStream: Driver"
- " does not support VIDEO_2DOP_FILL");
- return Length-rem;
- }
-
- Handlers->Fill(
- Ent,
- ((const Uint16*)stream)[0], ((const Uint16*)stream)[1],
- ((const Uint16*)stream)[2], ((const Uint16*)stream)[3],
- ((const Uint32*)stream)[4]
- );
-
- rem -= 10;
- stream += 10;
- break;
-
- case VIDEO_2DOP_BLIT:
- if(rem < 12) return Length-rem;
-
- if(!Handlers->Blit) {
- Log_Warning("DrvUtil", "DrvUtil_Video_2DStream: Driver"
- " does not support VIDEO_2DOP_BLIT");
- return Length-rem;
- }
-
- Handlers->Blit(
- Ent,
- ((const Uint16*)stream)[0], ((const Uint16*)stream)[1],
- ((const Uint16*)stream)[2], ((const Uint16*)stream)[3],
- ((const Uint16*)stream)[4], ((const Uint16*)stream)[5]
- );
-
- rem -= 12;
- stream += 12;
- break;
-
- }
- }
- return 0;
-}
-
-int DrvUtil_Video_WriteLFB(tDrvUtil_Video_BufInfo *FBInfo, size_t Offset, size_t Length, const void *Buffer)
-{
- Uint8 *dest;
- const Uint32 *src = Buffer;
- int csr_x, csr_y;
- int x, y;
- int bytes_per_px = (FBInfo->Depth + 7) / 8;
- ENTER("pFBInfo xOffset xLength pBuffer",
- FBInfo, Offset, Length, Buffer);
-
- csr_x = FBInfo->CursorX;
- csr_y = FBInfo->CursorY;
-
- DrvUtil_Video_RemoveCursor(FBInfo);
-
- switch( FBInfo->BufferFormat )
- {
- case VIDEO_BUFFMT_TEXT:
- {
- const tVT_Char *chars = Buffer;
- int widthInChars = FBInfo->Width/giVT_CharWidth;
- int heightInChars = FBInfo->Height/giVT_CharHeight;
- int i;
-
- LOG("bytes_per_px = %i", bytes_per_px);
- LOG("widthInChars = %i, heightInChars = %i", widthInChars, heightInChars);
-
- Length /= sizeof(tVT_Char); Offset /= sizeof(tVT_Char);
-
- x = Offset % widthInChars; y = Offset / widthInChars;
- LOG("x = %i, y = %i", x, y);
-
- // Sanity Check
- if(Offset > heightInChars * widthInChars) LEAVE_RET('i', 0);
- if(y >= heightInChars) LEAVE_RET('i', 0);
-
- if( Offset + Length > heightInChars*widthInChars )
- {
- Length = heightInChars*widthInChars - Offset;
- }
-
- dest = FBInfo->Framebuffer;
- LOG("dest = %p", dest);
- dest += y * giVT_CharHeight * FBInfo->Pitch;
- LOG("dest = %p", dest);
-
- for( i = 0; i < Length; i++ )
- {
- if( y >= heightInChars )
- {
- Log_Notice("DrvUtil", "Stopped at %i", i);
- break;
- }
-
- VT_Font_Render(
- chars->Ch,
- dest + x*giVT_CharWidth*bytes_per_px, FBInfo->Depth, FBInfo->Pitch,
- VT_Colour12toN(chars->BGCol, FBInfo->Depth),
- VT_Colour12toN(chars->FGCol, FBInfo->Depth)
- );
-
- chars ++;
- x ++;
- if( x >= widthInChars )
- {
- x = 0;
- y ++;
- dest += FBInfo->Pitch*giVT_CharHeight;
- LOG("dest = %p", dest);
- }
- }
- Length = i * sizeof(tVT_Char);
- }
- break;
-
- case VIDEO_BUFFMT_FRAMEBUFFER:
- if(FBInfo->Width*FBInfo->Height*4 < Offset+Length)
- {
- Log_Warning("DrvUtil", "DrvUtil_Video_WriteLFB - Framebuffer Overflow");
- return 0;
- }
-
- switch(FBInfo->Depth)
- {
- case 15:
- case 16:
- Log_Warning("DrvUtil", "TODO: Support 15/16 bpp modes in LFB write");
- break;
- case 24:
- x = Offset % FBInfo->Width;
- y = Offset / FBInfo->Width;
- dest = (Uint8*)FBInfo->Framebuffer + y*FBInfo->Pitch;
- for( ; Length >= 4; Length -= 4 )
- {
- dest[x*3+0] = *src & 0xFF;
- dest[x*3+1] = (*src >> 8) & 0xFF;
- dest[x*3+2] = (*src >> 16) & 0xFF;
- x ++;
- if(x == FBInfo->Width) {
- dest += FBInfo->Pitch;
- x = 0;
- }
- }
- break;
- case 32:
- // Copy to Frambuffer
- if( FBInfo->Pitch != FBInfo->Width*4 )
- {
- Uint32 *px;
- // Pitch isn't 4*Width
- x = Offset % FBInfo->Width;
- y = Offset / FBInfo->Height;
-
- px = (Uint32*)FBInfo->Framebuffer + y*FBInfo->Pitch/4;
-
- for( ; Length >= 4; Length -= 4, x )
- {
- px[x++] = *src ++;
- if( x == FBInfo->Width ) {
- x = 0;
- px += FBInfo->Pitch;
- }
- }
- }
- else
- {
- dest = (Uint8 *)FBInfo->Framebuffer + Offset;
- memcpy(dest, Buffer, Length);
- }
- break;
- default:
- Log_Warning("DrvUtil", "DrvUtil_Video_WriteLFB - Unknown bit depthn %i", FBInfo->Depth);
- break;
- }
- break;
-
- case VIDEO_BUFFMT_2DSTREAM:
- Length = DrvUtil_Video_2DStream(
- FBInfo, Buffer, Length,
- &gDrvUtil_Stub_2DFunctions, sizeof(gDrvUtil_Stub_2DFunctions)
- );
- break;
-
- default:
- LEAVE('i', -1);
- return -1;
- }
-
- DrvUtil_Video_DrawCursor(FBInfo, csr_x, csr_y);
-
- LEAVE('x', Length);
- return Length;
-}
-
-int DrvUtil_Video_SetCursor(tDrvUtil_Video_BufInfo *Buf, tVideo_IOCtl_Bitmap *Bitmap)
-{
- int csrX = Buf->CursorX, csrY = Buf->CursorY;
- size_t size;
-
- ENTER("pBuf pBitmap", Buf, Bitmap);
-
- // Clear old bitmap
- if( Buf->CursorBitmap )
- {
- LOG("Clearing old cursor");
- DrvUtil_Video_RemoveCursor(Buf);
- if( !Bitmap || Bitmap->W != Buf->CursorBitmap->W || Bitmap->H != Buf->CursorBitmap->H )
- {
- free( Buf->CursorSaveBuf );
- Buf->CursorSaveBuf = NULL;
- }
- if( Buf->CursorBitmap != &gDrvUtil_TextModeCursor)
- free(Buf->CursorBitmap);
- Buf->CursorBitmap = NULL;
- }
-
- // If the new bitmap is null, disable drawing
- if( !Bitmap )
- {
- Buf->CursorX = -1;
- Buf->CursorY = -1;
- LEAVE('i', 0);
- return 0;
- }
-
- // Sanity check the bitmap
- LOG("Sanity checking plox");
- if( !CheckMem(Bitmap, sizeof(*Bitmap)) || !CheckMem(Bitmap->Data, Bitmap->W*Bitmap->H*sizeof(Uint32)) )
- {
- Log_Warning("DrvUtil", "DrvUtil_Video_SetCursor: Bitmap (%p) is in invalid memory", Bitmap);
- errno = -EINVAL;
- LEAVE('i', -1);
- return -1;
- }
-
- // Don't take a copy of the DrvUtil provided cursor
- if( Bitmap == &gDrvUtil_TextModeCursor )
- {
- LOG("No copy (provided cursor)");
- Buf->CursorBitmap = Bitmap;
- }
- else
- {
- LOG("Make copy");
- size = sizeof(tVideo_IOCtl_Bitmap) + Bitmap->W*Bitmap->H*4;
-
- // Take a copy
- Buf->CursorBitmap = malloc( size );
- memcpy(Buf->CursorBitmap, Bitmap, size);
- }
-
- // Restore cursor position
- LOG("Drawing");
- DrvUtil_Video_DrawCursor(Buf, csrX, csrY);
- LEAVE('i', 0);
- return 0;
-}
-
-void DrvUtil_Video_DrawCursor(tDrvUtil_Video_BufInfo *Buf, int X, int Y)
-{
- int render_ox=0, render_oy=0, render_w, render_h;
-
- ENTER("pBuf iX iY", Buf, X, Y);
- DrvUtil_Video_RemoveCursor(Buf);
-
- // X < 0 disables the cursor
- if( X < 0 ) {
- Buf->CursorX = -1;
- LEAVE('-');
- return ;
- }
-
- // Sanity checking
- if( X < 0 || Y < 0 || X >= Buf->Width || Y >= Buf->Height ) {
- LEAVE('-');
- return ;
- }
-
- // Ensure the cursor is enabled
- if( !Buf->CursorBitmap ) {
- LEAVE('-');
- return ;
- }
-
- // Save cursor position (for changing the bitmap)
- Buf->CursorX = X; Buf->CursorY = Y;
- // Apply cursor's center offset
- X -= Buf->CursorBitmap->XOfs;
- Y -= Buf->CursorBitmap->YOfs;
-
- // Get the width of the cursor on screen (clipping to right/bottom edges)
- render_w = X > Buf->Width - Buf->CursorBitmap->W ? Buf->Width - X : Buf->CursorBitmap->W;
- render_h = Y > Buf->Height - Buf->CursorBitmap->H ? Buf->Height - Y : Buf->CursorBitmap->H;
-
- // Clipp to left/top edges
- if(X < 0) { render_ox = -X; X = 0; }
- if(Y < 0) { render_oy = -Y; Y = 0; }
-
- // Save values
- Buf->CursorRenderW = render_w; Buf->CursorRenderH = render_h;
- Buf->CursorDestX = X; Buf->CursorDestY = Y;
- Buf->CursorReadX = render_ox; Buf->CursorReadY = render_oy;
-
- LOG("%ix%i at %i,%i offset %i,%i",
- render_w, render_h, X, Y, render_ox, render_oy);
-
- // Call render routine
- DrvUtil_Video_RenderCursor(Buf);
- LEAVE('-');
-}
-
-void DrvUtil_Video_RenderCursor(tDrvUtil_Video_BufInfo *Buf)
-{
- int src_x = Buf->CursorReadX, src_y = Buf->CursorReadY;
- int render_w = Buf->CursorRenderW, render_h = Buf->CursorRenderH;
- int dest_x = Buf->CursorDestX, dest_y = Buf->CursorDestY;
- int bytes_per_px = (Buf->Depth + 7) / 8;
- int save_pitch = Buf->CursorBitmap->W * bytes_per_px;
- void *dest;
- Uint32 *src;
- int x, y;
-
- dest = (Uint8*)Buf->Framebuffer + dest_y*Buf->Pitch + dest_x*bytes_per_px;
- src = Buf->CursorBitmap->Data + src_y * Buf->CursorBitmap->W + src_x;
-
- LOG("dest = %p, src = %p", dest, src);
-
- // Allocate save buffer if not already
- if( !Buf->CursorSaveBuf )
- Buf->CursorSaveBuf = malloc( Buf->CursorBitmap->W*Buf->CursorBitmap->H*bytes_per_px );
-
- LOG("Saving back");
- // Save behind the cursor
- for( y = 0; y < render_h; y ++ )
- memcpy(
- (Uint8*)Buf->CursorSaveBuf + y*save_pitch,
- (Uint8*)dest + y*Buf->Pitch,
- render_w*bytes_per_px
- );
-
- // Draw the cursor
- switch(Buf->Depth)
- {
- case 15:
- case 16:
- Log_Warning("DrvUtil", "TODO: Support 15/16 bpp modes in cursor draw");
- break;
- case 24:
- LOG("24-bit render");
- for( y = 0; y < render_h; y ++ )
- {
- Uint8 *px;
- px = dest;
- for(x = 0; x < render_w; x ++, px += 3)
- {
- Uint32 value = src[x];
- // TODO: Should I implement alpha blending?
- if(value & 0xFF000000)
- {
- px[0] = value & 0xFF;
- px[1] = (value >> 8) & 0xFF;
- px[2] = (value >> 16) & 0xFF;
- }
- else
- ;
- }
- src += Buf->CursorBitmap->W;
- dest = (Uint8*)dest + Buf->Pitch;
- }
- break;
- case 32:
- LOG("32-bit render");
- for( y = 0; y < render_h; y ++ )
- {
- Uint32 *px;
- px = dest;
- for(x = 0; x < render_w; x ++, px ++)
- {
- Uint32 value = src[x];
- // TODO: Should I implement alpha blending?
- if(value & 0xFF000000)
- *px = value;
- else
- ; // NOP, completely transparent
- }
- LOG("row %i/%i (%p-%P) done", y+1, render_h, dest, MM_GetPhysAddr(dest));
- src += Buf->CursorBitmap->W;
- dest = (Uint8*)dest + Buf->Pitch;
- }
- break;
- default:
- Log_Error("DrvUtil", "RenderCursor - Unknown bit depth %i", Buf->Depth);
- Buf->CursorX = -1;
- break;
- }
-}
-
-void DrvUtil_Video_RemoveCursor(tDrvUtil_Video_BufInfo *Buf)
-{
- int bytes_per_px = (Buf->Depth + 7) / 8;
- int y, save_pitch;
- Uint8 *dest, *src;
-
- // Just a little sanity
- if( !Buf->CursorBitmap || Buf->CursorX == -1 ) return ;
- if( !Buf->CursorSaveBuf ) return ;
-
-// Debug("DrvUtil_Video_RemoveCursor: (Buf=%p) dest_x=%i, dest_y=%i", Buf, Buf->CursorDestX, Buf->CursorDestY);
-
- // Set up
- save_pitch = Buf->CursorBitmap->W * bytes_per_px;
- dest = (Uint8*)Buf->Framebuffer + Buf->CursorDestY * Buf->Pitch + Buf->CursorDestX*bytes_per_px;
- src = Buf->CursorSaveBuf;
-
- // Copy each line back
- for( y = 0; y < Buf->CursorRenderH; y ++ )
- {
- memcpy( dest, src, Buf->CursorRenderW * bytes_per_px );
- src += save_pitch;
- dest += Buf->Pitch;
- }
-
- // Set the cursor as removed
- Buf->CursorX = -1;
-}
-
-void DrvUtil_Video_2D_Fill(void *Ent, Uint16 X, Uint16 Y, Uint16 W, Uint16 H, Uint32 Colour)
-{
- tDrvUtil_Video_BufInfo *FBInfo = Ent;
-
- // TODO: Handle non-32bit modes
- if( FBInfo->Depth != 32 ) return;
-
- // TODO: Be less hacky
- int pitch = FBInfo->Pitch/4;
- Uint32 *buf = (Uint32*)FBInfo->Framebuffer + Y*pitch + X;
- while( H -- ) {
- Uint32 *tmp;
- int i;
- tmp = buf;
- for(i=W;i--;tmp++) *tmp = Colour;
- buf += pitch;
- }
-}
-
-void DrvUtil_Video_2D_Blit(void *Ent, Uint16 DstX, Uint16 DstY, Uint16 SrcX, Uint16 SrcY, Uint16 W, Uint16 H)
-{
- tDrvUtil_Video_BufInfo *FBInfo = Ent;
- int scrnpitch = FBInfo->Pitch;
- int bytes_per_px = (FBInfo->Depth + 7) / 8;
- int dst = DstY*scrnpitch + DstX;
- int src = SrcY*scrnpitch + SrcX;
- int tmp;
-
- //Log("Vesa_2D_Blit: (Ent=%p, DstX=%i, DstY=%i, SrcX=%i, SrcY=%i, W=%i, H=%i)",
- // Ent, DstX, DstY, SrcX, SrcY, W, H);
-
- if(SrcX + W > FBInfo->Width) W = FBInfo->Width - SrcX;
- if(DstX + W > FBInfo->Width) W = FBInfo->Width - DstX;
- if(SrcY + H > FBInfo->Height) H = FBInfo->Height - SrcY;
- if(DstY + H > FBInfo->Height) H = FBInfo->Height - DstY;
-
- //Debug("W = %i, H = %i", W, H);
-
- if( dst > src ) {
- // Reverse copy
- dst += H*scrnpitch;
- src += H*scrnpitch;
- while( H -- ) {
- dst -= scrnpitch;
- src -= scrnpitch;
- tmp = W*bytes_per_px;
- for( tmp = W; tmp --; ) {
- *((Uint8*)FBInfo->Framebuffer + dst + tmp) = *((Uint8*)FBInfo->Framebuffer + src + tmp);
- }
- }
- }
- else if(W == FBInfo->Width && FBInfo->Pitch == FBInfo->Width*bytes_per_px) {
- memmove((Uint8*)FBInfo->Framebuffer + dst, (Uint8*)FBInfo->Framebuffer + src, H*FBInfo->Pitch);
- }
- else {
- // Normal copy is OK
- while( H -- ) {
- memcpy((Uint8*)FBInfo->Framebuffer + dst, (Uint8*)FBInfo->Framebuffer + src, W*bytes_per_px);
- dst += scrnpitch;
- src += scrnpitch;
- }
- }
- //Log("Vesa_2D_Blit: RETURN");
-}
-
-
-// --- Disk Driver Helpers ---
-Uint64 DrvUtil_ReadBlock(Uint64 Start, Uint64 Length, void *Buffer,
- tDrvUtil_Read_Callback ReadBlocks, Uint64 BlockSize, void *Argument)
-{
- Uint8 tmp[BlockSize]; // C99
- Uint64 block = Start / BlockSize;
- int offset = Start - block * BlockSize;
- int leading = BlockSize - offset;
- Uint64 num;
- int tailings;
- Uint64 ret;
-
- ENTER("XStart XLength pBuffer pReadBlocks XBlockSize pArgument",
- Start, Length, Buffer, ReadBlocks, BlockSize, Argument);
-
- // Non aligned start, let's fix that!
- if(offset != 0)
- {
- if(leading > Length) leading = Length;
- LOG("Reading %i bytes from Block1+%i", leading, offset);
- ret = ReadBlocks(block, 1, tmp, Argument);
- if(ret != 1) {
- LEAVE('i', 0);
- return 0;
- }
- memcpy( Buffer, &tmp[offset], leading );
-
- if(leading == Length) {
- LEAVE('i', leading);
- return leading;
- }
-
- Buffer = (Uint8*)Buffer + leading;
- block ++;
- num = ( Length - leading ) / BlockSize;
- tailings = Length - num * BlockSize - leading;
- }
- else {
- num = Length / BlockSize;
- tailings = Length % BlockSize;
- }
-
- // Read central blocks
- if(num)
- {
- LOG("Reading %i blocks", num);
- ret = ReadBlocks(block, num, Buffer, Argument);
- if(ret != num ) {
- LEAVE('X', leading + ret * BlockSize);
- return leading + ret * BlockSize;
- }
- }
-
- // Read last tailing block
- if(tailings != 0)
- {
- LOG("Reading %i bytes from last block", tailings);
- block += num;
- Buffer = (Uint8*)Buffer + num * BlockSize;
- ret = ReadBlocks(block, 1, tmp, Argument);
- if(ret != 1) {
- LEAVE('X', leading + num * BlockSize);
- return leading + num * BlockSize;
- }
- memcpy( Buffer, tmp, tailings );
- }
-
- LEAVE('X', Length);
- return Length;
-}
-
-Uint64 DrvUtil_WriteBlock(Uint64 Start, Uint64 Length, const void *Buffer,
- tDrvUtil_Read_Callback ReadBlocks, tDrvUtil_Write_Callback WriteBlocks,
- Uint64 BlockSize, void *Argument)
-{
- Uint8 tmp[BlockSize]; // C99
- Uint64 block = Start / BlockSize;
- int offset = Start - block * BlockSize;
- int leading = BlockSize - offset;
- Uint64 num;
- int tailings;
- Uint64 ret;
-
- ENTER("XStart XLength pBuffer pReadBlocks pWriteBlocks XBlockSize pArgument",
- Start, Length, Buffer, ReadBlocks, WriteBlocks, BlockSize, Argument);
-
- // Non aligned start, let's fix that!
- if(offset != 0)
- {
- if(leading > Length) leading = Length;
- LOG("Writing %i bytes to Block1+%i", leading, offset);
- // Read a copy of the block
- ret = ReadBlocks(block, 1, tmp, Argument);
- if(ret != 1) {
- LEAVE('i', 0);
- return 0;
- }
- // Modify
- memcpy( &tmp[offset], Buffer, leading );
- // Write Back
- ret = WriteBlocks(block, 1, tmp, Argument);
- if(ret != 1) {
- LEAVE('i', 0);
- return 0;
- }
-
- if(leading == Length) {
- LEAVE('i', leading);
- return leading;
- }
-
- Buffer = (Uint8*)Buffer + leading;
- block ++;
- num = ( Length - leading ) / BlockSize;
- tailings = Length - num * BlockSize - leading;
- }
- else {
- num = Length / BlockSize;
- tailings = Length % BlockSize;
- }
-
- // Read central blocks
- if(num)
- {
- LOG("Writing %i blocks", num);
- ret = WriteBlocks(block, num, Buffer, Argument);
- if(ret != num ) {
- LEAVE('X', leading + ret * BlockSize);
- return leading + ret * BlockSize;
- }
- }
-
- // Read last tailing block
- if(tailings != 0)
- {
- LOG("Writing %i bytes to last block", tailings);
- block += num;
- Buffer = (Uint8*)Buffer + num * BlockSize;
- // Read
- ret = ReadBlocks(block, 1, tmp, Argument);
- if(ret != 1) {
- LEAVE('X', leading + num * BlockSize);
- return leading + num * BlockSize;
- }
- // Modify
- memcpy( tmp, Buffer, tailings );
- // Write
- ret = WriteBlocks(block, 1, tmp, Argument);
- if(ret != 1) {
- LEAVE('X', leading + num * BlockSize);
- return leading + num * BlockSize;
- }
-
- }
-
- LEAVE('X', Length);
- return Length;
-}