Kernel/VTerm - Replace offset WritePos with Row,Col pair

[tpg/acess2.git] / KernelLand / Kernel / drv / vterm_termbuf.c

diff --git a/KernelLand/Kernel/drv/vterm_termbuf.c b/KernelLand/Kernel/drv/vterm_termbuf.c
index d4ea9a4..4902cd8 100644 (file)
--- a/KernelLand/Kernel/drv/vterm_termbuf.c
+++ b/KernelLand/Kernel/drv/vterm_termbuf.c
@@ -5,7 +5,7 @@
  * drv/vterm_termbuf.c
  * - Virtual Terminal - Terminal buffer manipulation
  */
-#define DEBUG  0
+#define DEBUG  1
 #define DEBUG_CHECKHEAP        0
 #include "vterm.h"
 
@@ -65,60 +65,71 @@ void VT_int_PutChar(tVTerm *Term, Uint32 Ch)
        
        HEAP_VALIDATE();
        
-       size_t  limit = VT_int_GetBufferRows(Term) * Term->TextWidth;
-       size_t  write_pos = *VT_int_GetWritePosPtr(Term);
+       const size_t    maxrows = VT_int_GetBufferRows(Term);
+       const size_t    limit = maxrows * Term->TextWidth;
+       tVT_Pos *wrpos = VT_int_GetWritePosPtr(Term);
        tVT_Char        *buffer = (Term->Flags & VT_FLAG_ALTBUF ? Term->AltBuf : Term->Text);
 
-       ASSERTC(write_pos, >=, 0);
+       // If writing with the cursor on righthand edge, wrap down to next line
+       // TODO: Wrap to same line?
+       if( wrpos->Col >= Term->TextWidth )
+       {
+               ASSERTC(wrpos->Col, <=, Term->TextWidth);
+               VT_int_UpdateScreen( Term, 0 );
+               //wrpos->Row ++;
+               wrpos->Col = 0;
+       }
 
        // Scroll entire buffer (about to write outside limit)
-       if( write_pos >= limit )
+       if( wrpos->Row >= maxrows )
        {
-               ASSERTC(write_pos, <, limit + Term->TextWidth);
+               ASSERTC(wrpos->Row, <, maxrows + 1);
                VT_int_ScrollText(Term, 1);
-               write_pos -= Term->TextWidth;
+               wrpos->Row --;
        }
 
        // Bring written cell into view
        if( !(Term->Flags & VT_FLAG_ALTBUF) )
        {
-               size_t  onescreen = Term->TextWidth*Term->TextHeight;
-               if( write_pos >= Term->ViewPos + onescreen )
+               if( wrpos->Row >= Term->ViewTopRow + Term->TextHeight )
                {
-                       size_t  new_pos = write_pos - (write_pos % Term->TextWidth) - onescreen + Term->TextWidth;
-                       size_t  count = (new_pos - Term->ViewPos) / Term->TextWidth;
+                       size_t  new_pos = wrpos->Row - (Term->TextHeight - 1);
+                       size_t  count = new_pos - Term->ViewTopRow;
                        VT_int_ScrollFramebuffer(Term, count);
-                       //Debug("VT_int_PutChar: VScroll down to %i", new_pos/Term->TextWidth);
-                       Term->ViewPos = new_pos;
+                       //Debug("VT_int_PutChar: VScroll down to %i", new_pos);
+                       Term->ViewTopRow = new_pos;
                }
-               else if( write_pos < Term->ViewPos )
+               else if( wrpos->Row < Term->ViewTopRow )
                {
-                       size_t  new_pos = write_pos - (write_pos % Term->TextWidth);
-                       size_t  count = (Term->ViewPos - new_pos) / Term->TextWidth;
+                       size_t  new_pos = wrpos->Row;
+                       size_t  count = Term->ViewTopRow - new_pos;
                        VT_int_ScrollFramebuffer(Term, -count);
-                       //Debug("VT_int_PutChar: VScroll up to %i", new_pos/Term->TextWidth);
-                       Term->ViewPos = new_pos;
+                       //Debug("VT_int_PutChar: VScroll up to %i", new_pos);
+                       Term->ViewTopRow = new_pos;
                }
                else
                {
                        // no action, cell is visible
                }
        }
-       
+
+       size_t  write_pos = wrpos->Row * Term->TextWidth + wrpos->Col;
+       ASSERTC(write_pos, <, limit);
+
        switch(Ch)
        {
        case '\0':      // Ignore NULL byte
                return;
        case '\n':
                VT_int_UpdateScreen( Term, 0 ); // Update the line before newlining
-               write_pos += Term->TextWidth;
-               // TODO: Scroll display down if needed
+               wrpos->Row ++;
+               // TODO: Force scroll?
        case '\r':
-               write_pos -= write_pos % Term->TextWidth;
+               wrpos->Col = 0;
                break;
        
        case '\t': {
-               size_t  col =  write_pos % Term->TextWidth;
+               size_t  col = wrpos->Col;
                do {
                        buffer[ write_pos ].Ch = '\0';
                        buffer[ write_pos ].Colour = Term->CurColour;
@@ -147,6 +158,7 @@ void VT_int_PutChar(tVTerm *Term, Uint32 Ch)
                } while(write_pos && i-- && buffer[ write_pos ].Ch == '\0');
                if(buffer[ write_pos ].Ch != '\0')
                        write_pos ++;
+               wrpos->Col = write_pos % Term->TextWidth;
                break;
        
        default:
@@ -156,11 +168,11 @@ void VT_int_PutChar(tVTerm *Term, Uint32 Ch)
                if( (write_pos + 1) % Term->TextWidth == 0 )
                        VT_int_UpdateScreen( Term, 0 );
                write_pos ++;
+               wrpos->Col ++;
                break;
        }
        
        ASSERTC(write_pos, <=, limit);
-       *VT_int_GetWritePosPtr(Term) = write_pos;
 
        HEAP_VALIDATE();
        
@@ -176,7 +188,7 @@ void VT_int_ScrollText(tVTerm *Term, int Count)
 
        // Get buffer pointer and attributes    
        size_t  height = VT_int_GetBufferRows(Term);
-       size_t  *write_pos_ptr = VT_int_GetWritePosPtr(Term);
+       tVT_Pos *wrpos = VT_int_GetWritePosPtr(Term);
        
        if( Term->Flags & VT_FLAG_ALTBUF )
        {
@@ -191,7 +203,7 @@ void VT_int_ScrollText(tVTerm *Term, int Count)
                scroll_height = height;
        }
        
-       const int init_write_pos = *write_pos_ptr;
+       const tVT_Pos init_wrpos = *wrpos;
 
        // Scroll text upwards (more space at bottom)
        if( Count > 0 )
@@ -217,13 +229,13 @@ void VT_int_ScrollText(tVTerm *Term, int Count)
                // Update Screen
                VT_int_ScrollFramebuffer( Term, Count );
                if( Term->Flags & VT_FLAG_ALTBUF )
-                       Term->AltWritePos = base;
+                       wrpos->Row = scroll_top;
                else
-                       Term->WritePos = Term->ViewPos + Term->TextWidth*(Term->TextHeight - Count);
+                       wrpos->Row = Term->ViewTopRow + (Term->TextHeight - Count);
                for( int i = 0; i < Count; i ++ )
                {
                        VT_int_UpdateScreen( Term, 0 );
-                       *write_pos_ptr += Term->TextWidth;
+                       wrpos->Row ++;
                }
        }
        else
@@ -249,16 +261,17 @@ void VT_int_ScrollText(tVTerm *Term, int Count)
                // Update screen (shift framebuffer, re-render revealed lines)
                VT_int_ScrollFramebuffer( Term, -Count );
                if( Term->Flags & VT_FLAG_ALTBUF )
-                       Term->AltWritePos = Term->TextWidth*scroll_top;
+                       wrpos->Row = scroll_top;
                else
-                       Term->WritePos = Term->ViewPos;
+                       wrpos->Row = Term->ViewTopRow;
                for( int i = 0; i < Count; i ++ )
                {
                        VT_int_UpdateScreen( Term, 0 );
+                       // Increment?
                }
        }
        
-       *write_pos_ptr = init_write_pos;
+       *wrpos = init_wrpos;
 
        HEAP_VALIDATE();
 }
@@ -422,7 +435,7 @@ void VT_int_ToggleAltBuffer(tVTerm *Term, int Enabled)
        VT_int_UpdateScreen(Term, 1);
 }
 
-size_t *VT_int_GetWritePosPtr(tVTerm *Term)
+tVT_Pos *VT_int_GetWritePosPtr(tVTerm *Term)
 {
        return ((Term->Flags & VT_FLAG_ALTBUF) ? &Term->AltWritePos : &Term->WritePos);
 }