int test_gdi_SetPixel(void)
{
HGDI_DC hdc;
int width = 128;
int height = 64;
HGDI_BITMAP hBitmap;
if (!(hdc = gdi_GetDC()))
{
printf("failed to get gdi device context\n");
return -1;
}
hdc->bytesPerPixel = 4;
hdc->bitsPerPixel = 32;
hBitmap = gdi_CreateCompatibleBitmap(hdc, width, height);
gdi_SelectObject(hdc, (HGDIOBJECT) hBitmap);
gdi_SetPixel(hdc, 32, 64, 0xAABBCCDD);
if (gdi_GetPixel(hdc, 32, 64) != 0xAABBCCDD)
return -1;
gdi_SetPixel(hdc, width - 1, height - 1, 0xAABBCCDD);
if (gdi_GetPixel(hdc, width - 1, height - 1) != 0xAABBCCDD)
return -1;
gdi_DeleteObject((HGDIOBJECT) hBitmap);
return 0;
}
static void Ellipse_Bresenham(HGDI_DC hdc, int x1, int y1, int x2, int y2)
{
INT32 e, e2;
INT32 dx, dy;
INT32 a, b, c;
a = (x1 < x2) ? x2 - x1 : x1 - x2;
b = (y1 < y2) ? y2 - y1 : y1 - y2;
c = b & 1;
dx = 4 * (1 - a) * b * b;
dy = 4 * (c + 1) * a * a;
e = dx + dy + c * a * a;
if (x1 > x2)
{
x1 = x2;
x2 += a;
}
if (y1 > y2)
y1 = y2;
y1 += (b + 1) / 2;
y2 = y1 - c;
a *= 8 * a;
c = 8 * b * b;
do
{
gdi_SetPixel(hdc, x2, y1, 0);
gdi_SetPixel(hdc, x1, y1, 0);
gdi_SetPixel(hdc, x1, y2, 0);
gdi_SetPixel(hdc, x2, y2, 0);
e2 = 2 * e;
if (e2 >= dx)
{
x1++;
x2--;
e += dx += c;
}
if (e2 <= dy)
{
y1++;
y2--;
e += dy += a;
}
}
while (x1 <= x2);
while (y1 - y2 < b)
{
gdi_SetPixel(hdc, x1 - 1, ++y1, 0);
gdi_SetPixel(hdc, x1 - 1, --y2, 0);
}
}