Merge pull request #1493 from nicolasnoble/soft-math-project

Adding projection to soft math.

Author: nicolasnoble

src/mips/psyqo/soft-math.hh

@@ -111,15 +111,15 @@ FixedPoint<> matrixDeterminant3(const Matrix33 *m);
  * @param x The number to compute the square root of.
  * @return psyqo::FixedPoint<> The square root.
  */
-psyqo::FixedPoint<> squareRoot(psyqo::FixedPoint<> x);
+FixedPoint<> squareRoot(FixedPoint<> x);
 
 /**
  * @brief Computes the norm of a 3D vector.
  *
  * @param v The vector.
  * @return psyqo::FixedPoint<> The norm.
  */
-psyqo::FixedPoint<> normOfVec3(const Vec3 *v);
+FixedPoint<> normOfVec3(const Vec3 *v);
 
 /**
  * @brief Normalizes a 3D vector.
@@ -128,6 +128,15 @@ psyqo::FixedPoint<> normOfVec3(const Vec3 *v);
  */
 void normalizeVec3(Vec3 *v);
 
+/**
+ * @brief Projects a 3D point onto a 2D plane.
+ *
+ * @param v The vector to project.
+ * @param h The height of the plane.
+ * @param out The vector to store the result in.
+ */
+void project(const Vec3 *v, FixedPoint<> h, Vec2 *out);
+
 }  // namespace SoftMath
 
 }  // namespace psyqo

src/mips/psyqo/src/soft-math.cpp

@@ -231,3 +231,14 @@ void psyqo::SoftMath::normalizeVec3(Vec3 *v) {
     v->y = y;
     v->z = z;
 }
+
+void psyqo::SoftMath::project(const Vec3 *v, FixedPoint<> h, Vec2 *out) {
+    auto x = v->x;
+    auto y = v->y;
+    auto z = v->z;
+    auto r = h / z;
+    x = x * r;
+    y = y * r;
+    out->x = x;
+    out->y = y;
+}