Proj v1, ready.

port_draw in multiple T classes.
pb v1.
proj v1, ready.
WinMain v3.

SpaceCadetPinball/proj.cpp

@@ -0,0 +1,62 @@
+#include "pch.h"
+#include "proj.h"
+
+mat4_row_major proj::matrix;
+float proj::d_, proj::centerx, proj::centery;
+
+void proj::init(float* mat4x3, float d, float centerX, float centerY)
+{
+	//for (auto colIndex = 0; colIndex < 4; ++colIndex)
+	//{
+	//	// Todo: out of bounds read from mat4x3?
+	//	for (int rowIndex = colIndex, i = 4; i > 0; rowIndex += 4, --i)
+	//	{
+	//		((float*)&matrix)[rowIndex] = mat4x3[rowIndex];
+	//	}
+	//}
+	memcpy(&matrix, mat4x3, sizeof(float) * 4 * 3);
+
+	matrix.Row3.X = 0.0;
+	matrix.Row3.Y = 0.0;
+	matrix.Row3.Z = 0.0;
+	matrix.Row3.W = 1.0;
+
+	d_ = d;
+	centerx = centerX;
+	centery = centerY;
+}
+
+void proj::matrix_vector_multiply(mat4_row_major* mat, vector_type* vec, vector_type* dstVec)
+{
+	const float x = vec->X, y = vec->Y, z = vec->Z;
+	dstVec->X = z * mat->Row0.Z + y * mat->Row0.Y + x * mat->Row0.X + mat->Row0.W;
+	dstVec->Y = z * mat->Row1.Z + y * mat->Row1.Y + x * mat->Row1.X + mat->Row1.W;
+	dstVec->Z = z * mat->Row2.Z + y * mat->Row2.Y + x * mat->Row2.X + mat->Row2.W;
+}
+
+float proj::z_distance(vector_type* vec)
+{
+	vector_type dstVec{};
+	matrix_vector_multiply(&matrix, vec, &dstVec);
+	return maths::magnitude(&dstVec);
+}
+
+void proj::xform_to_2d(vector_type* vec, int* dst)
+{
+	float projCoef;
+	vector_type dstVec2{};
+
+	matrix_vector_multiply(&matrix, vec, &dstVec2);
+	if (0.0 == dstVec2.Z)
+		projCoef = 999999.88f;
+	else
+		projCoef = d_ / dstVec2.Z;
+	dst[0] = static_cast<int>(dstVec2.X * projCoef + centerx);
+	dst[1] = static_cast<int>(dstVec2.Y * projCoef + centery);
+}
+
+void proj::recenter(float centerX, float centerY)
+{
+	centerx = centerX;
+	centery = centerY;
+}