orbit camera

2 files changed, 77 insertions, 15 deletions

diff --git a/c2.cpp b/c2.cpp
index d7b475e..e721190 100644
--- a/c2.cpp
+++ b/c2.cpp
@@ -91,6 +91,71 @@ static Sampler_Id create_clamped_linear(Device* dev) {
 	return dev->create_sampler("repeated linear", s);
 }
 
+struct Orbit_Cam : public Camera {
+	bool first_frame;
+	v3f target;
+	int px, py;
+	int pscroll;
+	float yrot = 0.0f;
+	static constexpr float sense = 5.0f;
+	static constexpr float min_dist = 0.3f;
+
+	void init() {
+		pscroll = 0;
+		first_frame = true;
+		target = v3f(0.0f);
+		position = v3f(0.0f, 0.0f, -5.0f);
+		Camera::init(
+			90.0f,
+			v3f::normalised(target - position),
+			position
+		);
+	}
+
+	void update(const App& app) {
+		float dx = ((float)(px - app.mx) / (float)app.w) * sense;
+		float dy = ((float)(py - app.my) / (float)app.h) * sense;
+		int dscroll = pscroll - app.scrolly;
+		if (app.mjp(mbtn_middle) || app.mjp(mbtn_right))
+			dx = dy = 0.0f;
+		if (app.mp(mbtn_middle)) {
+			v3f left = v3f::cross(forward, v3f(0.0f, 1.0f, 0.0f));
+			v3f up = v3f::cross(forward, left);
+			float dist = v3f::mag(position - target);
+			position += left * v3f(dx) * dist; 
+			position += up * v3f(dy) * dist;
+			target = position + forward * dist;
+			forward = v3f::normalised(target - position);
+		}
+		if (app.mp(mbtn_right)) {
+			m4f rotation = m4f::rotate(
+				m4f::identity(),
+				forward.z < 0.0f? (float)dy: (float)-dy,
+				v3f(1.0f, 0.0f, 0.0f)
+			) * m4f::rotate(
+				m4f::identity(),
+				(float)dx,
+				v3f(0.0f, 1.0f, 0.0f)
+			);
+			v4f pos = v4f(position - target, 0.0f);
+			yrot += dy;
+			pos = rotation * pos;
+			position = target + v3f(pos.x, pos.y, pos.z);
+			forward = v3f::normalised(target - position);
+		}
+		if (dscroll) {
+			v3f zp = position - forward * (float)dscroll;
+			float dist = v3f::mag(zp - target);
+			if (dist < min_dist || v3f::dot(forward, zp - target) > 0.0f)
+				zp = target - forward * min_dist;
+			position = zp;
+		}
+		px = app.mx;
+		py = app.my;
+		pscroll = app.scrolly;
+	}
+};
+
 struct Config_Buffer {
 	float offset[2];
 };
@@ -112,7 +177,7 @@ extern "C" int entrypoint() {
 	Texture_Id default_texture;
 	Model_Instance* monkey, * monkey2;
 	Model_Scene scene;
-	Camera camera;
+	Orbit_Cam camera;
 	Buffer_Id vbo, cbuf;
 	Sampler_Id clamped_linear;
 	C2* app = App::create<C2>("c2");
@@ -176,11 +241,7 @@ extern "C" int entrypoint() {
 		dev,
 		(Model*)assets.load("monkey.mdl")
 	);
-	camera.init(
-		90.0f,
-		v3f(0.0f, 0.0f, 1.0f),
-		v3f(0.0f, 0.0f, 0.0f)
-	);
+	camera.init();
 	while (app->running) {
 		Arena frame_arena;
 		init_arena(&frame_arena, per_frame, per_frame_memory_size);
@@ -254,23 +315,24 @@ extern "C" int entrypoint() {
 		Render_Pass& pass2 = pb.build_rp();
 
 		Texture& bb = dev->get_texture(dev->get_backbuffer());
-		monkey->transform = (m4f::translate(
+		monkey->transform = m4f::translate(
 			m4f::identity(),
-			v3f(0.0f, 0.0f, -5.0f)
-		) * m4f::rotate(
+			v3f(0.0f, 0.0f, 0.0f)
+		)/* * m4f::rotate(
 			m4f::identity(),
 			rot,
 			raxis
-		));
-		monkey2->transform = (m4f::translate(
+		)*/;
+		monkey2->transform = m4f::translate(
 			m4f::identity(),
-			v3f(2.0f, 0.0f, -7.0f)
-		) * m4f::rotate(
+			v3f(2.0f, 0.0f, 2.0f)
+		)/* * m4f::rotate(
 			m4f::identity(),
 			rot * 2.0f,
 			v3f(1.0f, 0.0f, 0.0f)
-		));
+		)*/;
 		camera.asp = (float)bb.w / (float)bb.h;
+		camera.update(*app);
 		scene.update(camera, dev);
 		ctx.debug_push("scene");
 		ctx.debug_push("depth prepass");
diff --git a/model.cpp b/model.cpp
index 0b1dee7..4c5edcc 100644
--- a/model.cpp
+++ b/model.cpp
@@ -304,7 +304,7 @@ void Model_Instance::update_cbuffers(
 		0,
 		c * sizeof *mats
 	);
-	m4f view_projection = cam.get_proj();
+	m4f view_projection = cam.get_proj() * cam.get_view();
 	for (i = 0; i < c; i++) {
 		Mat_Cbuffer& mat = mats[i];
 		Material& sm = *meshes[i].material;