Implement rudimentary player movement; fix geometry logic bugs

[shadowclad.git] / src / engine / geometry.c

diff --git a/src/engine/geometry.c b/src/engine/geometry.c
index 7af8c1cc47217c46249490f462374897acaa9492..2cfb0aac767936b896d59531a70ad5555bc97f5c 100644 (file)
--- a/src/engine/geometry.c
+++ b/src/engine/geometry.c
@@ -17,17 +17,19 @@ Transform identity() {
 Transform multiply(Transform t1, Transform t2) {
        GLfloat* a = (GLfloat*) &t1;
        GLfloat* b = (GLfloat*) &t2;
+       Transform result;
+       GLfloat* c = (GLfloat*) &result;
 
        for (size_t row = 0; row < 4; ++row) {
                for (size_t col = 0; col < 4; ++col) {
-                       b[(row * 4) + col] =
+                       c[(row * 4) + col] =
                                a[(row * 4) + 0] * b[(0 * 4) + col]
                                + a[(row * 4) + 1] * b[(1 * 4) + col]
                                + a[(row * 4) + 2] * b[(2 * 4) + col]
                                + a[(row * 4) + 3] * b[(3 * 4) + col];
                }
        }
-       return t2;
+       return result;
 }
 
 void translate(Transform* transform, Vector3D vec) {
@@ -47,6 +49,7 @@ void rotate(Transform* transform, Vector3D axis, float angle) {
        float sinA = sinf(angle);
        float cosA = cosf(angle);
        float omcA = 1 - cosA;
+
        *transform = multiply(
                (Transform) { l*l*omcA + cosA, m*l*omcA - n*sinA, n*l*omcA + m*sinA, 0.0f,
                              l*m*omcA + n*sinA, m*m*omcA + cosA, n*m*omcA - l*sinA, 0.0f,
@@ -55,7 +58,7 @@ void rotate(Transform* transform, Vector3D axis, float angle) {
                *transform);
 }
 
-Vector3D applyTransform(Transform* transform, Vector3D vec) {
+Vector3D applyTransform(Transform transform, Vector3D vec) {
        GLfloat* a = (GLfloat*) &transform;
        GLfloat b[4] = { vec.x, vec.y, vec.z, 1.0f };
        GLfloat c[4];