Files
SDL3CPlusPlus/scripts/cube_logic.lua
2025-12-19 16:39:30 +00:00

333 lines
9.1 KiB
Lua

local pyramid_vertices = {
{ position = {0.0, 1.0, 0.0}, color = {1.0, 0.5, 0.0} },
{ position = {-1.0, -1.0, -1.0}, color = {0.0, 1.0, 1.0} },
{ position = {1.0, -1.0, -1.0}, color = {1.0, 0.0, 1.0} },
{ position = {1.0, -1.0, 1.0}, color = {1.0, 1.0, 0.0} },
{ position = {-1.0, -1.0, 1.0}, color = {0.0, 0.0, 1.0} },
}
local pyramid_indices = {
1, 2, 3,
1, 3, 4,
1, 4, 5,
1, 5, 2,
2, 3, 4,
4, 5, 2,
}
local cube_mesh_info = {
path = "models/cube.stl",
loaded = false,
vertex_count = 0,
index_count = 0,
error = "load_mesh_from_file() not registered",
}
local cube_vertices = {}
local cube_indices = {}
local function load_cube_mesh()
if type(load_mesh_from_file) ~= "function" then
cube_mesh_info.error = "load_mesh_from_file() is unavailable"
return
end
local mesh, err = load_mesh_from_file(cube_mesh_info.path)
if not mesh then
cube_mesh_info.error = err or "load_mesh_from_file() failed"
return
end
if type(mesh.vertices) ~= "table" or type(mesh.indices) ~= "table" then
cube_mesh_info.error = "loader returned unexpected structure"
return
end
cube_vertices = mesh.vertices
cube_indices = mesh.indices
cube_mesh_info.loaded = true
cube_mesh_info.vertex_count = #mesh.vertices
cube_mesh_info.index_count = #mesh.indices
cube_mesh_info.error = nil
end
load_cube_mesh()
if not cube_mesh_info.loaded then
error("Unable to load cube mesh: " .. (cube_mesh_info.error or "unknown"))
end
local math3d = require("math3d")
local string_format = string.format
local table_concat = table.concat
local InputState = {}
InputState.__index = InputState
function InputState:new()
local instance = {
mouseX = 0.0,
mouseY = 0.0,
mouseDown = false,
wheel = 0.0,
textInput = "",
keyStates = {},
}
return setmetatable(instance, InputState)
end
function InputState:resetTransient()
self.textInput = ""
self.wheel = 0.0
end
function InputState:setMouse(x, y, isDown)
self.mouseX = x
self.mouseY = y
self.mouseDown = isDown
end
function InputState:setWheel(deltaY)
self.wheel = deltaY
end
function InputState:setKey(keyName, isDown)
self.keyStates[keyName] = isDown
end
function InputState:addTextInput(text)
if text then
self.textInput = self.textInput .. text
end
end
gui_input = InputState:new()
local function log_debug(fmt, ...)
if not lua_debug or not fmt then
return
end
print(string_format(fmt, ...))
end
if cube_mesh_info.loaded then
log_debug("Loaded cube mesh from %s (%d vertices, %d indices)",
cube_mesh_info.path, cube_mesh_info.vertex_count, cube_mesh_info.index_count)
end
local cube_body_name = "cube_body"
local cube_state = {
position = {0.0, 0.0, 0.0},
rotation = {0.0, 0.0, 0.0, 1.0},
}
local physics_last_time = 0.0
local function quaternion_to_matrix(q)
local x, y, z, w = q[1], q[2], q[3], q[4]
local xx = x * x
local yy = y * y
local zz = z * z
local xy = x * y
local xz = x * z
local yz = y * z
local wx = w * x
local wy = w * y
local wz = w * z
return {
1.0 - 2.0 * yy - 2.0 * zz, 2.0 * xy + 2.0 * wz, 2.0 * xz - 2.0 * wy, 0.0,
2.0 * xy - 2.0 * wz, 1.0 - 2.0 * xx - 2.0 * zz, 2.0 * yz + 2.0 * wx, 0.0,
2.0 * xz + 2.0 * wy, 2.0 * yz - 2.0 * wx, 1.0 - 2.0 * xx - 2.0 * yy, 0.0,
0.0, 0.0, 0.0, 1.0,
}
end
local function initialize_physics()
if type(physics_create_box) ~= "function" then
error("physics_create_box() is unavailable")
end
local ok, err = physics_create_box(
cube_body_name,
{1.0, 1.0, 1.0},
1.0,
{0.0, 2.0, 0.0},
{0.0, 0.0, 0.0, 1.0}
)
if not ok then
error("physics_create_box failed: " .. (err or "unknown"))
end
if type(physics_step_simulation) == "function" then
physics_step_simulation(0.0)
end
end
initialize_physics()
local function sync_physics(time)
local dt = time - physics_last_time
if dt < 0.0 then
dt = 0.0
end
if dt > 0.0 and type(physics_step_simulation) == "function" then
physics_step_simulation(dt)
end
physics_last_time = time
if type(physics_get_transform) ~= "function" then
error("physics_get_transform() is unavailable")
end
local transform, err = physics_get_transform(cube_body_name)
if not transform then
error("physics_get_transform failed: " .. (err or "unknown"))
end
cube_state.position = transform.position
cube_state.rotation = transform.rotation
end
local rotation_speeds = {x = 0.5, y = 0.7}
local shader_variants = {
default = {
vertex = "shaders/cube.vert.spv",
fragment = "shaders/cube.frag.spv",
},
cube = {
vertex = "shaders/cube.vert.spv",
fragment = "shaders/cube.frag.spv",
},
pyramid = {
vertex = "shaders/cube.vert.spv",
fragment = "shaders/cube.frag.spv",
},
}
local camera = {
eye = {2.0, 2.0, 2.5},
center = {0.0, 0.0, 0.0},
up = {0.0, 1.0, 0.0},
fov = 0.78,
near = 0.1,
far = 10.0,
}
local zoom_settings = {
min_distance = 2.0,
max_distance = 12.0,
speed = 0.25,
}
local function clamp_distance(value, minValue, maxValue)
if minValue and value < minValue then
return minValue
end
if maxValue and value > maxValue then
return maxValue
end
return value
end
local function update_camera_zoom(delta)
if delta == 0 then
return
end
local dx = camera.eye[1] - camera.center[1]
local dy = camera.eye[2] - camera.center[2]
local dz = camera.eye[3] - camera.center[3]
local distance = math.sqrt(dx * dx + dy * dy + dz * dz)
if distance == 0 then
return
end
local normalizedX = dx / distance
local normalizedY = dy / distance
local normalizedZ = dz / distance
local adjustment = -delta * zoom_settings.speed
local targetDistance = clamp_distance(distance + adjustment, zoom_settings.min_distance, zoom_settings.max_distance)
camera.eye[1] = camera.center[1] + normalizedX * targetDistance
camera.eye[2] = camera.center[2] + normalizedY * targetDistance
camera.eye[3] = camera.center[3] + normalizedZ * targetDistance
log_debug("zoom delta=%.2f -> distance=%.2f", delta, targetDistance)
end
local function build_model(time)
local y = math3d.rotation_y(time * rotation_speeds.y)
local x = math3d.rotation_x(time * rotation_speeds.x)
return math3d.multiply(y, x)
end
local function create_rotating_cube(position, speed_scale, shader_key)
local function compute_model_matrix(time)
local base = build_model(time * speed_scale)
local offset = math3d.translation(position[1], position[2], position[3])
return math3d.multiply(offset, base)
end
return {
vertices = cube_vertices,
indices = cube_indices,
compute_model_matrix = compute_model_matrix,
shader_key = shader_key or "cube",
}
end
local function create_physics_cube(shader_key)
local function compute_model_matrix(time)
sync_physics(time)
local offset = math3d.translation(
cube_state.position[1],
cube_state.position[2],
cube_state.position[3]
)
local rotation_matrix = quaternion_to_matrix(cube_state.rotation)
return math3d.multiply(offset, rotation_matrix)
end
return {
vertices = cube_vertices,
indices = cube_indices,
compute_model_matrix = compute_model_matrix,
shader_key = shader_key or "cube",
}
end
local function create_pyramid(position, shader_key)
local function compute_model_matrix(time)
local base = build_model(time * 0.6)
local offset = math3d.translation(position[1], position[2], position[3])
return math3d.multiply(offset, base)
end
return {
vertices = pyramid_vertices,
indices = pyramid_indices,
compute_model_matrix = compute_model_matrix,
shader_key = shader_key or "pyramid",
}
end
function get_scene_objects()
local objects = {
create_physics_cube("cube"),
create_rotating_cube({3.0, 0.0, 0.0}, 0.8, "cube"),
create_rotating_cube({-3.0, 0.0, 0.0}, 1.2, "cube"),
create_pyramid({0.0, -0.5, -4.0}, "pyramid"),
}
if lua_debug then
local labels = {}
for idx, obj in ipairs(objects) do
table.insert(labels, string_format("[%d:%s]", idx, obj.shader_key))
end
log_debug("get_scene_objects -> %d entries: %s", #objects, table_concat(labels, ", "))
end
return objects
end
function get_shader_paths()
return shader_variants
end
function get_view_projection(aspect)
if gui_input then
update_camera_zoom(gui_input.wheel)
end
local view = math3d.look_at(camera.eye, camera.center, camera.up)
local projection = math3d.perspective(camera.fov, aspect, camera.near, camera.far)
return math3d.multiply(projection, view)
end