private void DrawScanLine(PrimitiveContext ctx, int y, float xe, float xd)
{
int xmin = glm.Max((int)xe, 0);
int xmax = glm.Min((int)xd, (int)m_CurrentViewport.width);
int ib = ctx.baseIndex;
float w0 = ctx.w[ctx.iV0];
float w1 = ctx.w[ctx.iV1];
float w2 = ctx.w[ctx.iV2];
float dn01 = Linear2Homo(ctx.dfd01, w0, w1);
float dn12 = Linear2Homo(ctx.dfd12, w1, w2);
float dn02 = Linear2Homo(ctx.dfe02, w0, w2);
float dn21 = Linear2Homo(ctx.dfe21, w2, w1);
float dr01 = 1f - dn01;
float dr12 = 1f - dn12;
float dr02 = 1f - dn02;
float dr21 = 1f - dn21;
float bn012 = ctx.dfd012;
float bn021 = ctx.dfe021;
float br012 = 1f - bn012;
float br021 = 1f - bn021;
float R0 = dr01 * br012;
float R1 = dr02 * br021;
float R23 = dn01 * br012 + dr12 * bn012;
float R4 = dn21 * bn021;
float R5 = dn12 * bn012;
float R67 = dn02 * br021 + dr21 * bn021;
float wLeft = w0 * R1 + w1 * R4 + w2 * R67;
float wRight = w0 * R0 + w1 * R23 + w2 * R5;
float zLeft = ctx.v[ctx.iV0].z * R1 + ctx.v[ctx.iV1].z * R4 + ctx.v[ctx.iV2].z * R67;
float zRight = ctx.v[ctx.iV0].z * R0 + ctx.v[ctx.iV1].z * R23 + ctx.v[ctx.iV2].z * R5;
float deltaDx = (xd != xe) ? 1f / (float)(xd - xe) : 0f;
for (int x = xmin; x <= xmax; x++)
{
float dx = (float)(x - xe) * deltaDx;
dx = Linear2Homo(dx, wLeft, wRight);
float z = zLeft + (zRight - zLeft) * dx;
internal_FragCoord.x = x;
internal_FragCoord.y = y;
if (m_DepthBuffer.IsDepthTestEnabled())
{
if (!m_DepthBuffer.TestDepth(internal_FragCoord, z))
{
continue;
}
}
m_DepthBuffer.WriteDepth(internal_FragCoord, z);
ctx.RDX[ctx.iV0] = R1 + ((R0 - R1) * dx);
ctx.RDX[ctx.iV1] = R4 + ((R23 - R4) * dx);
ctx.RDX[ctx.iV2] = R67 + ((R5 - R67) * dx);
gl_FragCoord.x = x;
gl_FragCoord.y = y;
gl_FragCoord.z = z;
gl_FragCoord.w = 1; // TODO: gl_FragCoord.w = 1/w ?
// RUN FRAGMENT SHADER
// RunStage(StageType.FragmentShader);
m_CompiledPipelineProgram.FragmentShader();
}
}
