diff options
| -rw-r--r-- | core/graphics.inc | 71 |
1 files changed, 47 insertions, 24 deletions
diff --git a/core/graphics.inc b/core/graphics.inc index 3ba51465..884776ea 100644 --- a/core/graphics.inc +++ b/core/graphics.inc @@ -75,22 +75,26 @@ vgadisplayfile: mov di,VGARowBuffer ; Pre-clear the row buffer push di + push di mov cx,640/4 xor eax,eax rep stosd pop di - push di mov cx,[GraphXSize] call rledecode ; Decode one row pop si + mov di,VGAPlaneBuffer + push di + mov bp,640 + call packedpixel2vga + pop si push es mov di,0A000h ; VGA segment mov es,di mov di,[VGAPos] - mov bp,640 - call packedpixel2vga - add word [VGAPos],80 + call outputvga pop es + add word [VGAPos],640/8 pop cx loop .drawpixelrow @@ -160,39 +164,57 @@ rledecode: ; ; DS:SI -> packed pixel string ; BP -> pixel count (multiple of 8) -; ES:DI -> output +; DS:DI -> output (four planes) ; packedpixel2vga: - mov dx,3C4h ; VGA Sequencer Register select port - mov al,2 ; Sequencer mask - out dx,al ; Select the sequencer mask - inc dx ; VGA Sequencer Register data port - mov al,1 - mov bl,al + xor cx,cx .planeloop: - pusha - out dx,al + inc cx + push si + push bp .loop1: - mov cx,8 + mov bx,8 .loop2: - xchg cx,bx lodsb shr al,cl - rcl ch,1 ; VGA is bigendian. Sigh. - xchg cx,bx - loop .loop2 - mov al,bh - stosb + rcl dl,1 ; VGA is bigendian. Sigh. + dec bx + jnz .loop2 + mov [di],dl + inc di sub bp,byte 8 ja .loop1 - popa - inc bl - shl al,1 - cmp bl,4 + pop bp + pop si + cmp cl,3 jbe .planeloop ret ; +; outputvga: +; Output four subsequent lines of VGA data +; +; DS:SI -> four planes @ 640/8=80 bytes +; ES:DI -> pointer into VGA memory +; +outputvga: + mov dx,3C4h ; VGA Sequencer Register select port + mov al,2 ; Sequencer mask + out dx,al ; Select the sequencer mask + inc dx ; VGA Sequencer Register data port + dec ax ; AL <- 1 +.loop1: + out dx,al ; Select the bit plane to write + push di + mov cx,640/8 + rep movsb + pop di + add ax,ax + cmp al,8 + jbe .loop1 + ret + +; ; vgasetmode: ; Enable VGA graphics, if possible; return ZF=1 on success ; DS must be set to the base segment; ES is set to DS. @@ -328,3 +350,4 @@ VGAFileMBuf resb FILENAME_MAX ; Mangled VGA image name alignb 4 VGARowBuffer resb 640+80 ; Decompression buffer +VGAPlaneBuffer resb (640/8)*4 ; Plane buffers |