/*
        Copyright 2009 Haiku, Inc.  All rights reserved.
        Distributed under the terms of the MIT license.

        Authors:
        Gerald Zajac 2009
*/


#include "accelerant.h"
#include "mach64.h"

#include <string.h>



void
Mach64_ShowCursor(bool bShow)
{
        // Turn cursor on/off.

        OUTREGM(GEN_TEST_CNTL, bShow ? HWCURSOR_ENABLE : 0, HWCURSOR_ENABLE);
}


void
Mach64_SetCursorPosition(int x, int y)
{
        SharedInfo& si = *gInfo.sharedInfo;

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

        uint8 xOffset = 0;
        uint8 yOffset = 0;

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

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

        OUTREG(CUR_OFFSET, (si.cursorOffset >> 3) + (yOffset << 1));
        OUTREG(CUR_HORZ_VERT_OFF, (yOffset << 16) | xOffset);
        OUTREG(CUR_HORZ_VERT_POSN, (y << 16) | x);
}


bool
Mach64_LoadCursorImage(int width, int height, uint8* andMask, uint8* xorMask)
{
        SharedInfo& si = *gInfo.sharedInfo;

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

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

        // Initialize the hardware cursor as completely transparent.

        memset(fbCursor, 0xaa, CURSOR_BYTES);

        // 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

        for (int row = 0; row < height; row++) {
                for (int colByte = 0; colByte < width / 8; colByte++) {
                        // Convert the 8 bit AND and XOR masks into a 16 bit mask containing
                        // pairs of the bits from the AND and XOR maks.

                        uint8 andBits = *andMask++;
                        uint8 xorBits = *xorMask++;
                        uint16 cursorBits = 0;

                        for (int j = 0; j < 8; j++) {
                                cursorBits <<= 2;
                                cursorBits |= ((andBits & 0x01) << 1);
                                cursorBits |= (xorBits & 0x01);
                                andBits >>= 1;
                                xorBits >>= 1;
                        }

                        fbCursor[row * 8 + colByte] = cursorBits;
                }
        }

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

        OUTREG(CUR_CLR0, ~0);
        OUTREG(CUR_CLR1, 0);

        return true;
}