/*
        Haiku S3 Virge driver adapted from the X.org Virge driver.

        Copyright (C) 1994-1999 The XFree86 Project, Inc.       All Rights Reserved.

        Copyright 2007-2008 Haiku, Inc.  All rights reserved.
        Distributed under the terms of the MIT license.

        Authors:
        Gerald Zajac 2007-2008
*/

#include "accel.h"
#include "virge.h"



void 
Virge_ShowCursor(bool bShow)
{
        // Turn cursor on/off.

        WriteCrtcReg(0x45, bShow ? 0x01 : 0x00, 0x01);
}


void 
Virge_SetCursorPosition(int x, int y)
{
        uint8 xOffset = 0;
        uint8 yOffset = 0;

        // xOffset & yOffset are used for displaying partial cursors on screen edges.

        if (x < 0) {
                xOffset = (( -x) & 0xfe);
                x = 0;
        }

        if (y < 0) {
                yOffset = (( -y) & 0xfe);
                y = 0;
        }

        // Note: when setting the cursor position, register 48 must be set last
        // since setting register 48 activates the new cursor position.

        WriteCrtcReg( 0x4e, xOffset );
        WriteCrtcReg( 0x4f, yOffset );

        WriteCrtcReg( 0x47, (x & 0xff) );
        WriteCrtcReg( 0x46, (x & 0x0700) >> 8 );

        WriteCrtcReg( 0x49, (y & 0xff) );
        WriteCrtcReg( 0x48, (y & 0x0700) >> 8 );
}


bool 
Virge_LoadCursorImage(int width, int height, uint8* andMask, uint8* xorMask)
{
        SharedInfo& si = *gInfo.sharedInfo;

        if (andMask == NULL || xorMask == NULL)
                return false;

        // Initialize hardware cursor to be completely transparent.

        uint16* fbCursor16 = (uint16*)((addr_t)si.videoMemAddr + si.cursorOffset);

        for (int i = 0; i < CURSOR_BYTES; i += 4) {
                *fbCursor16++ = ~0;             // and bits
                *fbCursor16++ = 0;              // xor bits
        }

        // Now load the AND & XOR masks for the cursor image into the cursor
        // buffer.  Note that a particular bit in these masks will have the
        // following effect upon the corresponding cursor pixel:
        //      AND  XOR        Result
        //       0    0          White pixel
        //       0    1          Black pixel
        //       1    0          Screen color (for transparency)
        //       1    1          Reverse screen color to black or white

        uint8* fbCursor = (uint8*)((addr_t)si.videoMemAddr + si.cursorOffset);

        for (int row = 0; row < height; row++) {
                for (int colByte = 0; colByte < width / 8; colByte++) {
                        fbCursor[row * 16 + colByte] = *andMask++;
                        fbCursor[row * 16 + colByte + 2] = *xorMask++;
                }
        }

        // Set cursor location in video memory.

        WriteCrtcReg(0x4d, (0xff & si.cursorOffset / 1024));
        WriteCrtcReg(0x4c, (0x0f00 & si.cursorOffset / 1024) >> 8);

        // Set the cursor colors which are black foreground and white background.

        ReadCrtcReg(0x45);              // reset cursor color stack pointer
        WriteCrtcReg(0x4a, 0);  // set foreground color stack low, mid, high bytes
        WriteCrtcReg(0x4a, 0);
        WriteCrtcReg(0x4a, 0);

        ReadCrtcReg(0x45);              // reset cursor color stack pointer
        WriteCrtcReg(0x4b, ~0); // set background color stack low, mid, high bytes
        WriteCrtcReg(0x4b, ~0);
        WriteCrtcReg(0x4b, ~0);

        return true;
}