public static void DrawBlock(ref T shader, ref TriangleEquations eqn, int x, int y, bool TestEdges)
{
float xf = x + 0.5f;
float yf = y + 0.5f;
PixelData po = new PixelData();
po.Init(ref eqn, xf, yf, shader.AVarCount, shader.PVarCount, shader.InterpolateZ, shader.InterpolateW);
EdgeData eo = new EdgeData();
if (TestEdges)
{
eo.init(ref eqn, xf, yf);
}
for (int yy = y; yy < y + Constants.BlockSize; yy++)
{
PixelData pi = CopyPixelData(ref shader, ref po);
EdgeData ei = new EdgeData();
if (TestEdges)
{
ei = eo;
}
for (int xx = x; xx < x + Constants.BlockSize; xx++)
{
if (!TestEdges || ei.test(ref eqn))
{
pi.x = xx;
pi.y = yy;
shader.DrawPixel(ref pi);
}
pi.StepX(ref eqn, shader.AVarCount, shader.PVarCount, shader.InterpolateZ, shader.InterpolateW);
if (TestEdges)
{
ei.stepX(ref eqn);
}
}
po.StepY(ref eqn, shader.AVarCount, shader.PVarCount, shader.InterpolateZ, shader.InterpolateW);
if (TestEdges)
{
eo.stepY(ref eqn);
}
}
}
public void DrawTriangleBlockTemplate(ref RasterizerVertex v0, ref RasterizerVertex v1, ref RasterizerVertex v2)
{
// Compute triangle equations.
TriangleEquations eqn = new TriangleEquations(ref v0, ref v1, ref v2, shader.AVarCount, shader.PVarCount);
// Check if triangle is backfacing.
if (eqn.area2 <= 0)
{
return;
}
// Compute triangle bounding box.
int minX = (int)Math.Min(Math.Min(v0.x, v1.x), v2.x);
int maxX = (int)Math.Max(Math.Max(v0.x, v1.x), v2.x);
int minY = (int)Math.Min(Math.Min(v0.y, v1.y), v2.y);
int maxY = (int)Math.Max(Math.Max(v0.y, v1.y), v2.y);
// Clip to scissor rect.
minX = Math.Max(minX, rasterizer.m_minX);
maxX = Math.Min(maxX, rasterizer.m_maxX);
minY = Math.Max(minY, rasterizer.m_minY);
maxY = Math.Min(maxY, rasterizer.m_maxY);
// Round to block grid.
minX &= ~(Constants.BlockSize - 1);
maxX &= ~(Constants.BlockSize - 1);
minY &= ~(Constants.BlockSize - 1);
maxY &= ~(Constants.BlockSize - 1);
float s = Constants.BlockSize - 1;
int stepsX = (maxX - minX) / Constants.BlockSize + 1;
int stepsY = (maxY - minY) / Constants.BlockSize + 1;
for (int i = 0; i < stepsX * stepsY; ++i)
{
int sx = i % stepsX;
int sy = i / stepsX;
// Add 0.5 to sample at pixel centers.
int x = minX + sx * Constants.BlockSize;
int y = minY + sy * Constants.BlockSize;
float xf = x + 0.5f;
float yf = y + 0.5f;
// Test if block is inside or outside triangle or touches it.
EdgeData e00 = new EdgeData(); e00.init(ref eqn, xf, yf);
EdgeData e01 = e00; e01.stepY(ref eqn, s);
EdgeData e10 = e00; e10.stepX(ref eqn, s);
EdgeData e11 = e01; e11.stepX(ref eqn, s);
bool e00_0 = eqn.e0.test(e00.ev0), e00_1 = eqn.e1.test(e00.ev1), e00_2 = eqn.e2.test(e00.ev2), e00_all = e00_0 && e00_1 && e00_2;
bool e01_0 = eqn.e0.test(e01.ev0), e01_1 = eqn.e1.test(e01.ev1), e01_2 = eqn.e2.test(e01.ev2), e01_all = e01_0 && e01_1 && e01_2;
bool e10_0 = eqn.e0.test(e10.ev0), e10_1 = eqn.e1.test(e10.ev1), e10_2 = eqn.e2.test(e10.ev2), e10_all = e10_0 && e10_1 && e10_2;
bool e11_0 = eqn.e0.test(e11.ev0), e11_1 = eqn.e1.test(e11.ev1), e11_2 = eqn.e2.test(e11.ev2), e11_all = e11_0 && e11_1 && e11_2;
int result = (e00_all ? 1 : 0) + (e01_all ? 1 : 0) + (e10_all ? 1 : 0) + (e11_all ? 1 : 0);
// Potentially all out.
if (result == 0)
{
// Test for special case.
bool e00Same = e00_0 == e00_1 == e00_2;
bool e01Same = e01_0 == e01_1 == e01_2;
bool e10Same = e10_0 == e10_1 == e10_2;
bool e11Same = e11_0 == e11_1 == e11_2;
if (!e00Same || !e01Same || !e10Same || !e11Same)
{
shader.DrawBlock(ref eqn, x, y, true);
}
}
else if (result == 4)
{
// Fully Covered.
shader.DrawBlock(ref eqn, x, y, false);
}
else
{
// Partially Covered.
shader.DrawBlock(ref eqn, x, y, true);
}
}
}
