// Allocates a section of memory in the heap and returns
// the pointer to the beginning of the block. There is always
// a header describing the space remaining in the heap as free
// at the end of the linked list of headers.
void *myMalloc(size_t size) {
if (size <= 0) {
return NULL;
}
header *headerPointer = head;
header *temp;
if (headerPointer == NULL) {
headerPointer = firstMalloc(size);
}
else {
// While my header is not the last header and I am either not free
// or too small, continue down the linked list
while (headerPointer->next != NULL &&
!(headerPointer->freeFlag == TRUE && headerPointer->size >= size)) {
headerPointer = headerPointer->next;
}
if (headerPointer->next == NULL) {
mallocForTailHeader(headerPointer, size);
}
else {
// If there is enough space for my size and the size of the next
// header I need to make, use the space and make a new header to
// divide the block
if (headerPointer->size - size > headerSize) {
doMalloc(headerPointer, size);
}
// Else use the original block with its size that might be a
// little bigger than what was asked for
else {
headerPointer->freeFlag = FALSE;
}
}
}
// Align the pointer that is returned from malloc. This is safe to
// do because the extra padding that is given is large enough to
// allow the first bytes that block point to to be unused
return (void *) ceil16((intptr_t) (headerPointer + 1));
}
// Reallocates the block pointed to
void *myRealloc(void *ptr, size_t size) {
void *block = NULL;
header *headerBefore = getBeforePointerFromPointer(ptr);
header *headerPointer = getHeaderPointerFromBefore(headerBefore);
if (headerPointer->next->next == NULL) {
block = reallocateSecondToLastBlock(headerPointer, headerBefore, size);
}
else if (headerPointer == head) {
block = reallocFirstBlock(headerPointer, size);
}
else {
block = reallocMiddleBlock(headerPointer, headerBefore, size);
}
block = block == NULL ?
(void *) ceil16((intptr_t) (headerPointer + 1)) : block;
return block;
}
// This is my version of memmove. It is necessary because the
// allocated blocks might not be aligned with respect to each other
void myMemmove(void * destination, void *source, uint32_t size) {
return memmove((void *) ceil16((intptr_t) destination),
(void *) ceil16((intptr_t) source), size - PADDING);
}
void painter2D::draw_line(float x1, float y1, float x2, float y2,
unsigned char r, unsigned char g, unsigned char b,
imagebuffer *ib)
{
float prestep, fcy, faux, xd, yd;
int top_y, bottom_y, top_x, bottom_x, j;
int x, x_inc, y, y_inc, offset0, ofs, w;
unsigned int *img32, col32;
// rigetti banali
if ((x1<0) && (x2<0)) return;
if ((y1<0) && (y2<0)) return;
if ((x1>=(float)(ib->width)) &&
(x2>=(float)(ib->width))) return;
if ((y1>=(float)(ib->height)) &&
(y2>=(float)(ib->height))) return;
col32=(unsigned int)(b | (g << 8) | (r << 16));
xd=x2-x1;
yd=y2-y1;
img32=ib->uint32ptr;
if (fabsf(yd)>fabsf(xd))
{
if (y1>y2) { faux=y1; y1=y2; y2=faux; faux=x1; x1=x2; x2=faux; }
// subpixel + clipping
prestep=-y1;
if (y1>=0)
{
fcy=fceil(y1);
prestep=fcy + prestep;
top_y=myfist(fcy);
} else top_y=0;
if (y2 >= (float)(ib->height)) bottom_y=ib->height;
else bottom_y=myfist(fceil(y2));
faux=(x2 - x1)/(y2-y1);
x_inc=myfist16(faux);
x=myfist16(x1 + prestep*faux);
offset0=ib->muly[top_y];
for (j=abs(bottom_y-top_y); j>0; j--)
{
w=ceil16(x);
if ((w>=0) && (w<ib->width))
{
ofs=offset0 + w;
img32[ofs]=col32;
}
offset0=offset0+ib->width;
x+=x_inc;
}
}
else
{
if (x1>x2) { faux=y1; y1=y2; y2=faux; faux=x1; x1=x2; x2=faux; }
// subpixel + clipping
prestep=-x1;
if (x1>=0)
{
fcy=fceil(x1);
prestep=fcy + prestep;
bottom_x=myfist(fcy);
} else bottom_x=0;
if (x2 >= (float)(ib->width)) top_x=ib->width;
else top_x=myfist(fceil(x2));
faux=(y2-y1)/(x2-x1);
/*
if ((y1<0) && (y2>=0))
{
bottom_x=bottom_x + myfist(fceil(-y1/faux));
y1=0;
prestep=0;
}
else
if ((y1>=0) && (y2<0))
{
top_x=top_x - myfist(fceil(-y2/faux));
}
*/
y_inc=myfist16(faux);
y=myfist16(y1 + prestep*faux);
for (j=bottom_x; j<top_x; j++)
{
w=ceil16(y);
if ((w>=0) && (w<ib->height))
{
ofs=ib->muly[w]+j;
img32[ofs]=col32;
}
y+=y_inc;
}
}
}
void painter2D::draw_aaline(float x1, float y1, float x2, float y2,
unsigned char r, unsigned char g, unsigned char b,
imagebuffer *ib)
{
float prestep, fcy, faux, xd, yd;
int top_y, bottom_y, top_x, bottom_x, j, cx, fraz, ifraz;
int x, x_inc, y, y_inc, offset0, ofs, c1, c2, c3, w;
unsigned char *img;
// rigetti banali
if ((x1<0) && (x2<0)) return;
if ((y1<0) && (y2<0)) return;
if ((x1>(float)(ib->width)) &&
(x2>(float)(ib->width))) return;
if ((y1>(float)(ib->height)) &&
(y2>(float)(ib->height))) return;
xd=x2-x1;
yd=y2-y1;
img=ib->uchar8ptr;
if (fabsf(yd)>fabsf(xd))
{
if (y1>y2) { faux=y1; y1=y2; y2=faux; faux=x1; x1=x2; x2=faux; }
// subpixel + clipping
prestep=-y1;
if (y1>=0)
{
fcy=fceil(y1);
prestep=fcy + prestep;
top_y=myfist(fcy);
} else top_y=0;
if (y2 >= (float)(ib->height)) bottom_y=ib->height;
else bottom_y=myfist(fceil(y2));
faux=(x2 - x1)/(y2-y1);
x_inc=myfist16(faux);
x=myfist16(x1 + prestep*faux);
offset0=ib->muly[top_y];
for (j=abs(bottom_y-top_y); j>0; j--)
{
cx=ceil16(x);
if ((cx>=0) && (cx<ib->width-1))
{
ofs=offset0 + cx;
fraz=x & 0x0000FFFF;
ifraz=0x10000-fraz;
c1=(fraz*b)>>16;
c2=(fraz*g)>>16;
c3=(fraz*r)>>16;
img[ofs*4]=b-(unsigned char)c1;
img[ofs*4+1]=g-(unsigned char)c2;
img[ofs*4+2]=r-(unsigned char)c3;
c1=(ifraz*b)>>16;
c2=(ifraz*g)>>16;
c3=(ifraz*r)>>16;
img[ofs*4+4]=b-(unsigned char)c1;
img[ofs*4+5]=g-(unsigned char)c2;
img[ofs*4+6]=r-(unsigned char)c3;
}
offset0=offset0+ib->width;
x+=x_inc;
}
}
