public vec2d_f Backward(float x, float y)
{
vec2d_f ret = new vec2d_f(
x * _matrix[3, 0, 0] + y * _matrix[3, 1, 0] + _matrix[3, 2, 0],
x * _matrix[3, 0, 1] + y * _matrix[3, 1, 1] + _matrix[3, 2, 1]
);
float out_z = x * _matrix[3, 0, 2] + y * _matrix[3, 1, 2] + _matrix[3, 2, 2];
if (out_z != 0)
{
ret /= out_z;
}
return(ret);
}
public vec2d_f Forward(float x, float y)
{
vec2d_f ret = new vec2d_f(
x * _matrix[_sourceMatrix, 0, 0] + y * _matrix[_sourceMatrix, 1, 0] + _matrix[_sourceMatrix, 2, 0],
x * _matrix[_sourceMatrix, 0, 1] + y * _matrix[_sourceMatrix, 1, 1] + _matrix[_sourceMatrix, 2, 1]
);
float out_z = x * _matrix[_sourceMatrix, 0, 2] + y * _matrix[_sourceMatrix, 1, 2] + _matrix[_sourceMatrix, 2, 2];
if (out_z != 0)
{
ret /= out_z;
}
return(ret);
}
public void DrawSprite(Sprite sprite, Transform2D transform)
{
if (sprite == null)
{
return;
}
// Work out bounding rectangle of sprite
float ex = 0.0f, ey = 0.0f;
vec2d_f s = transform.Forward(0.0f, 0.0f);
vec2d_f p = new vec2d_f(s);
s.x = Math.Min(s.x, p.x);
s.y = Math.Min(s.y, p.y);
ex = Math.Max(ex, p.x);
ey = Math.Max(ey, p.y);
transform.Forward(sprite.Width, sprite.Height);
s.x = Math.Min(s.x, p.x);
s.y = Math.Min(s.y, p.y);
ex = Math.Max(ex, p.x);
ey = Math.Max(ey, p.y);
p = transform.Forward(0.0f, sprite.Height);
s.x = Math.Min(s.x, p.x);
s.y = Math.Min(s.y, p.y);
ex = Math.Max(ex, p.x);
ey = Math.Max(ey, p.y);
p = transform.Forward(sprite.Width, 0.0f);
s.x = Math.Min(s.x, p.x);
s.y = Math.Min(s.y, p.y);
ex = Math.Max(ex, p.x);
ey = Math.Max(ey, p.y);
// Perform inversion of transform if required
transform.Invert();
float sx = s.x;
float sy = s.y;
if (ex < sx)
{
PGEMath.Swap(ref ex, ref sx);
}
if (ey < sy)
{
PGEMath.Swap(ref ey, ref sy);
}
s.x = sx;
s.y = sy;
// Iterate through render space, and sample Sprite from suitable texel location
for (float i = s.x; i < ex; i++)
{
for (float j = s.y; j < ey; j++)
{
vec2d_f o = transform.Backward(i, j);
pge.Draw((uint)i, (uint)j, sprite.GetPixel((uint)(o.x + 0.5f), (uint)(o.y + 0.5f)));
}
}
}
