Move camera to world space position of player

diff --git a/src/engine/geometry.c b/src/engine/geometry.c
index 302dcde30e603bd7251e571417b828f6e754bb81..aa5de049407ae22e922b3b1fe83dbdc1e0d45d45 100644 (file)
--- a/src/engine/geometry.c
+++ b/src/engine/geometry.c
@@ -9,9 +9,9 @@ Transform identity() {
                             .d1 = 0.0f, .d2 = 0.0f, .d3 = 0.0f, .d4 = 1.0f };
 }
 
-void multiply(Transform* transform, Transform by) {
-       GLfloat* a = (GLfloat*) &by;
-       GLfloat* b = (GLfloat*) transform;
+Transform multiply(Transform t1, Transform t2) {
+       GLfloat* a = (GLfloat*) &t1;
+       GLfloat* b = (GLfloat*) &t2;
 
        for (size_t row = 0; row < 4; ++row) {
                for (size_t col = 0; col < 4; ++col) {
@@ -22,13 +22,16 @@ void multiply(Transform* transform, Transform by) {
                                + a[(row * 4) + 3] * b[(3 * 4) + col];
                }
        }
+       return t2;
 }
 
 void translate(Transform* transform, Vector3D vec) {
-       multiply(transform, (Transform) { .a1 = 1.0f, .a2 = 0.0f, .a3 = 0.0f, .a4 = vec.x,
-                                      .b1 = 0.0f, .b2 = 1.0f, .b3 = 0.0f, .b4 = vec.y,
-                                      .c1 = 0.0f, .c2 = 0.0f, .c3 = 1.0f, .c4 = vec.z,
-                                      .d1 = 0.0f, .d2 = 0.0f, .d3 = 0.0f, .d4 = 1.0f });
+       *transform = multiply(
+               (Transform) { .a1 = 1.0f, .a2 = 0.0f, .a3 = 0.0f, .a4 = vec.x,
+                             .b1 = 0.0f, .b2 = 1.0f, .b3 = 0.0f, .b4 = vec.y,
+                             .c1 = 0.0f, .c2 = 0.0f, .c3 = 1.0f, .c4 = vec.z,
+                             .d1 = 0.0f, .d2 = 0.0f, .d3 = 0.0f, .d4 = 1.0f },
+               *transform);
 }
 
 Vector3D translationOf(Transform transform) {

diff --git a/src/engine/geometry.h b/src/engine/geometry.h
index e883dc9a6aa7e5db3b317e7eb4c0837c95200bb5..cea05a64733854b312b4a4ecc80f567a6d0f9ed0 100644 (file)
--- a/src/engine/geometry.h
+++ b/src/engine/geometry.h
@@ -20,6 +20,7 @@ struct Transform {
 };
 
 Transform identity();
+Transform multiply(Transform t1, Transform t2);
 void translate(Transform* transform, Vector3D vec);
 Vector3D translationOf(Transform transform);
 

diff --git a/src/engine/render.c b/src/engine/render.c
index 121fe7d38893c208ce73476adf91d6603892f067..34c493a1dfe9462f13ee20e352bf1ef239e67537 100644 (file)
--- a/src/engine/render.c
+++ b/src/engine/render.c
@@ -96,7 +96,7 @@ static void setupCamera() {
 static void moveCameraTo(const Scene* anchor) {
        glMatrixMode(GL_PROJECTION);
        // TODO This needs to account for parent nodes as well
-       Vector3D pos = translationOf(anchor->transform);
+       Vector3D pos = translationOf(worldTransform(anchor));
        glTranslatef(-pos.x, -pos.y, -pos.z);
 }
 

diff --git a/src/engine/scene.c b/src/engine/scene.c
index 9b8c8dda28bb140fba4a0015fce3feaa96cb0846..a95dbec2fbce53ffc73c248a530f828e1317f2b0 100644 (file)
--- a/src/engine/scene.c
+++ b/src/engine/scene.c
@@ -24,7 +24,7 @@ void insertChildScene(Scene* scene, Scene* newChild) {
        }
        if (newChild->parent) {
                logError(
-                       "Cannot insert scene 0x%p as child of 0x%p, because it is already child of 0x%p",
+                       "Cannot insert Scene 0x%p as child of 0x%p, because it is already child of 0x%p",
                        newChild,
                        scene,
                        newChild->parent);
@@ -67,3 +67,18 @@ void reparentScene(Scene* scene, Scene* newParent) {
 
        insertChildScene(newParent, scene);
 }
+
+Transform worldTransform(const Scene* scene) {
+       if (!scene) {
+               logError("Cannot compute world space Transform of null Scene");
+               return identity();
+       }
+
+       if (scene->parent) {
+               return multiply(scene->transform, worldTransform(scene->parent));
+       }
+       else {
+               return scene->transform;
+       }
+}
+

diff --git a/src/engine/scene.h b/src/engine/scene.h
index c32694a365b556a85163f356fbf7a8b1aa4527e4..71c5912fca20751dee446e8c97713d51108db0c8 100644 (file)
--- a/src/engine/scene.h
+++ b/src/engine/scene.h
@@ -18,5 +18,6 @@ Scene* currentScene;
 Scene* newScene();
 void insertChildScene(Scene* scene, Scene* newChild);
 void reparentScene(Scene* scene, Scene* newParent);
+Transform worldTransform(const Scene* scene);
 
 #endif // SCENE_H_