//==========================================================================
/*
====================
=
= SC_ScaleShape
=
= Scales the shape centered on x,y to size scale (256=1:1, 512=2:1, etc)
=
= Clips to scalexl/scalexh, scaleyl/scaleyh
= Returns true if something was drawn
=
= Must be called in write mode 2!
=
====================
*/
private bool SC_ScaleShape(short x, short y, ushort scale, memptr shape)
{
short scalechop = (short) (scale / SCALESTEP - 1);
if(scalechop < 0)
return false; // can't scale this size
if(scalechop >= DISCREETSCALES)
scalechop = DISCREETSCALES - 1;
memptr basetoscreenptr = new memptr(basetableseg, basetables[scalechop]);
memptr screentobaseptr = new memptr(screentableseg, screentables[scalechop]);
//
// figure bounding rectangle for scaled image
//
scaleshape scaleshape_shape = new scaleshape(shape);
ushort fullwidth = (ushort) scaleshape_shape.width;
ushort fullheight = (ushort) scaleshape_shape.height;
ushort scalewidth = (ushort) (fullwidth * ((scalechop + 1) * SCALESTEP) / BASESCALE);
ushort scaleheight = basetoscreenptr.GetUInt8(fullheight - 1);
short xl = (short) (x - scalewidth / 2);
short xh = (short) (xl + scalewidth - 1);
short yl = (short) (y - scaleheight / 2);
short yh = (short) (yl + scaleheight - 1);
// off screen?
if(xl > scalexh || xh < scalexl || yl > scaleyh || yh < scaleyl)
return false;
//
// clip to sides of screen
//
short sxl;
if(xl < scalexl)
sxl = scalexl;
else
sxl = xl;
short sxh;
if(xh > scalexh)
sxh = scalexh;
else
sxh = xh;
//
// clip both sides to zbuffer
//
short sx = sxl;
while(sx <= sxh && zbuffer[sx] > scale) // as: re-ordered to prevent out of bounds read
sx++;
sxl = sx;
sx = sxh;
while(sx > sxl && zbuffer[sx] > scale) // as: re-ordered to prevent out of bounds read
sx--;
sxh = sx;
if(sxl > sxh)
return false; // behind a wall
//
// save block info for background erasing
//
ushort screencorner = (ushort) (screenofs + yl * linewidth);
scaleblockdest = (ushort) (screencorner + sxl / 8);
scaleblockwidth = (ushort) (sxh / 8 - sxl / 8 + 1);
scaleblockheight = (ushort) (yh - yl + 1);
//
// start drawing
//
for(sx = sxl; sx <= sxh; sx++)
{
short shapex = screentobaseptr.GetUInt8(sx - xl);
ushort shapeofs = scaleshape_shape.first(shapex);
if(shapeofs != 0)
{
short width = 1; // as: added for line drawing
ushort mask = masktable[sx];
if(scale > BASESCALE)
{
//
// make a multiple pixel scale pass if possible
//
while(((sx & 7) != 7) && (screentobaseptr.GetUInt8(sx + 1 - xl) == shapex))
{
sx++;
mask |= masktable[sx];
width++;
}
}
// Draw vertical spans
do
{
scaleseg shapeptr = new scaleseg(shape, shapeofs);
ushort yoffset = basetoscreenptr.GetUInt8(shapeptr.start); // pixels on screen to be skipped
short offset = 0;
if(width > 1)
offset = (short) (width - 1);
// as: added start x and width
ScaleLine(
basetoscreenptr.GetUInt8(shapeptr.length),
screentobaseptr,
shapeptr.PointerToData(0),
(ushort) (screencorner + ylookup[yoffset]),
sx - offset, width);
shapeofs = shapeptr.next;
} while(shapeofs != 0);
}
}
return true;
}
/*
===========================
=
= MakeShape
=
= Takes a raw bit map of width bytes by height and creates a scaleable shape
=
= Returns the length of the shape in bytes
=
===========================
*/
private void SC_MakeShape(memptr src, short width, short height, ref memptr shapeseg)
{
short pixwidth = (short) (width * 8);
memptr tempseg_memptr = new memptr(); // as: added
MMGetPtr(ref tempseg_memptr, pixwidth * (height + 20)); // larger than needed buffer
scaleshape tempseg = new scaleshape(tempseg_memptr);
tempseg.width = pixwidth; // pixel dimensions
tempseg.height = height;
//
// convert ega pixels to byte color values in a temp buffer
//
// Stored in a collumn format, not rows!
//
memptr byteseg = new memptr();
MMGetPtr(ref byteseg, pixwidth * height);
memptr byteptr = new memptr(byteseg);
memptr plane0 = new memptr(src);
memptr plane1 = new memptr(plane0, width * height);
memptr plane2 = new memptr(plane1, width * height);
memptr plane3 = new memptr(plane2, width * height);
for(short x = 0; x < width; x++)
{
for(ushort b = 0; b < 8; b++)
{
ushort shift = (ushort) (8 - b);
ushort offset = (ushort) x;
for(short y = 0; y < height; y++)
{
byte by0 = plane0.GetUInt8(offset);
byte by1 = plane1.GetUInt8(offset);
byte by2 = plane2.GetUInt8(offset);
byte by3 = plane3.GetUInt8(offset);
offset += (ushort) width;
ushort color = 0;
// as: converted from asm
color |= AsmRotate(by3, shift);
color <<= 1;
color |= AsmRotate(by2, shift);
color <<= 1;
color |= AsmRotate(by1, shift);
color <<= 1;
color |= AsmRotate(by0, shift);
byteptr.SetUInt8(0, (byte) color);
byteptr.Offset(1);
} // Y
} // B
} // X
//
// convert byte map to sparse scaling format
//
memptr saveptr = tempseg.PointerTofirst(pixwidth);
// start filling in data after all pointers to line segments
byteptr = new memptr(byteseg); // first pixel in byte array
for(short x = 0; x < pixwidth; x++)
{
//
// each vertical line can have 0 or more segments of pixels in it
//
short y = 0;
memptr segptr = tempseg.PointerTofirst(x);
segptr.SetUInt16(0, 0); // in case there are no segments on line
do
{
// scan for first pixel to be scaled
while(y < height && byteptr.GetUInt8(0) == BACKGROUND) // as: bugfix - re-ordered to prevent out of bounds read
{
byteptr.Offset(1);
y++;
}
if(y == height) // if not, the line is finished
continue;
//
// start a segment by pointing the last link (either shape.first[x] if it
// is the first segment, or a seg.next if not) to the current spot in
// the tempseg, setting segptr to this segments next link, and copying
// all the pixels in the segment
//
segptr.SetUInt16(0, _sys.FP_OFF(saveptr)); // pointer to start of this segment
short start = y;
short length = 0;
scaleseg scale_seg = new scaleseg(saveptr);
memptr dataptr = scale_seg.PointerToData(0);
//
// copy bytes in the segment to the shape
//
while(y < height && byteptr.GetUInt8(0) != BACKGROUND) // as: bugfix - re-ordered to prevent out of bounds read
{
length++;
dataptr.SetUInt8(0, byteptr.GetUInt8(0));
dataptr.Offset(1);
byteptr.Offset(1);
y++;
}
scale_seg.start = start;
scale_seg.length = length;
scale_seg.next = 0;
// get ready for next segment
segptr = new memptr(saveptr, scaleseg.FieldOffset_next);
saveptr = dataptr; // next free byte to be used
} while(y < height);
}
//
// allocate exact space needed and copy shape to it, then free buffers
//
MMGetPtr(ref shapeseg, _sys.FP_OFF(saveptr));
Array.Copy(tempseg.Pointer.Buffer, shapeseg.Buffer, _sys.FP_OFF(saveptr));
MMFreePtr(ref byteseg);
MMFreePtr(ref tempseg_memptr);
}
