some camera movement

data/scripts/game.lua

@@ -11,21 +11,59 @@ function start_blasting(track)
     audio_play(ctx.udata.blast)
 end
 
+function process_player(state)
+    input_action { name = "up", control = "W" }
+    input_action { name = "left", control = "A" }
+    input_action { name = "down", control = "S" }
+    input_action { name = "right", control = "D" }
+
+    local right = vec3_norm(vec3_cross(state.player.camera_direction, { x=0, y=1, z=0 }))
+    local up = { x = right.z, y = right.y, z = -right.x }
+
+    local direction = { x = 0, y = 0 , z = 0 }
+
+    if input_action_pressed { name = "up" } then
+        direction = vec3_add(direction, up)
+    end
+    if input_action_pressed { name = "down" } then
+        direction = vec3_sub(direction, up)
+    end
+    if input_action_pressed { name = "right" } then
+        direction = vec3_add(direction, right)
+    end
+    if input_action_pressed { name = "left" } then
+        direction = vec3_sub(direction, right)
+    end
+
+    if vec3_length(direction) > 0 then
+        direction = vec3_norm(direction)
+    end
+
+    state.player.position = vec3_add(state.player.position, vec3_scale(direction, state.player.speed / (60 / state.blast.bpm)))
+end
+
 function game_tick()
     if ctx.initialization_needed then
         ctx.udata = {
             time = 0,
             beat = 0,
+            player = {
+                position = { x=3, y=0, z=0 },
+                speed = 0.06, -- tiles per beat
+                camera_direction = { x=-math.sin(math.pi / 4), y=-1, z=math.cos(math.pi / 4) },
+            }
         }
-        start_blasting("mod22")
+        start_blasting("mod171")
     end
 
     local state = ctx.udata
 
+    process_player(state)
+
     draw_camera {
-        position = { x=0, y=0, z=0 },
+        position = state.player.position,
-        -- direction = { x=-math.sin(math.pi / 4), y=-1, z=math.cos(math.pi / 4) },
+        direction = state.player.camera_direction,
-        direction = { x=-math.sin(ctx.frame_number / 100), y=-1, z=math.cos(ctx.frame_number / 100) },
+        -- direction = { x=-math.sin(ctx.frame_number / 100), y=-1, z=math.cos(ctx.frame_number / 100) },
         up = { x=0, y=1, z=0 },
         fov = 0,
         zoom = 0.15 + math.sin(ctx.frame_number / 100) / 20,

data/scripts/traxx.lua

@@ -11,4 +11,10 @@ return {
         bpm = 177 / 2,
         loops = true,
     },
+
+    mod171 = {
+        audio = "traxx/mod171.xm",
+        bpm = 125,
+        loops = true,
+    },
 }

data/scripts/utils.lua

@@ -28,3 +28,39 @@ end
 function sinease(c, t, d, b)
     return -c*math.cos(t/d*(math.pi/2)) + c + b
 end
+
+function vec3_cross(a, b)
+    return {
+        x = a.y * b.z - a.z * b.y,
+        y = a.z * b.x - a.x * b.z,
+        z = a.x * b.y - a.y * b.x,
+    }
+end
+
+function vec3_dot(a, b)
+    return a.x * b.x + a.y * b.y + a.z * b.z
+end
+
+function vec3_scale(a, s)
+    return {
+        x = a.x * s,
+        y = a.y * s,
+        z = a.z * s,
+    }
+end
+
+function vec3_norm(a)
+    return vec3_scale(a, 1.0 / math.sqrt(vec3_dot(a, a)))
+end
+
+function vec3_add(a, b)
+    return { x = a.x + b.x, y = a.y + b.y, z = a.z + b.z }
+end
+
+function vec3_sub(a, b)
+    return { x = a.x - b.x, y = a.y - b.y, z = a.z - b.z }
+end
+
+function vec3_length(a)
+    return math.sqrt(a.x * a.x + a.y * a.y + a.z * a.z)
+end