model.py

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#!/usr/bin/env python3
## @file model.py
## @brief Interactive Python MXVK model loader and renderer.
## @details Loads an OBJ or MXMOD asset, builds NumPy transform matrices, and
## renders the model with mouse-controlled camera interaction. The resource
## path selects the shader and texture data directory used by the example.
##
## @section model_run Running the example
## @code{.sh}
## python3 python-examples/model/model.py --resolution 1280x720
## python3 python-examples/model/model.py --input models/pyramid.obj --enable-vsync
## @endcode
## @section model_controls Controls
## - Drag with the left mouse button: orbit the camera.
## - Mouse wheel: zoom.
## - Escape: exit.
## @section model_lifecycle Lifecycle
## @c ModelWindow creates and renders @c AbstractModel through the Python
## binding, then calls model cleanup before releasing the Vulkan window.
 
from __future__ import annotations
 
import argparse
import math
import sys
import time
from pathlib import Path
import numpy as np
import mxvk_ext as mxvk
 
EXAMPLE_DIR = Path(__file__).resolve().parent
 
def matrix_values(matrix: np.ndarray) -> list[float]:
    return matrix.astype(np.float32, copy=False).reshape(16).tolist()
 
def identity_matrix() -> np.ndarray:
    return np.eye(4, dtype=np.float32)
 
def rotation_y_matrix(angle: float) -> np.ndarray:
    cosine = math.cos(angle)
    sine = math.sin(angle)
    return np.array([[cosine, 0.0, sine, 0.0], [0.0, 1.0, 0.0, 0.0], [-sine, 0.0, cosine, 0.0], [0.0, 0.0, 0.0, 1.0]], dtype=np.float32)
 
def scale_matrix(x: float, y: float, z: float) -> np.ndarray:
    return np.array([[x, 0.0, 0.0, 0.0], [0.0, y, 0.0, 0.0], [0.0, 0.0, z, 0.0], [0.0, 0.0, 0.0, 1.0]], dtype=np.float32)
 
def translation_matrix(x: float, y: float, z: float) -> np.ndarray:
    return np.array([[1.0, 0.0, 0.0, x], [0.0, 1.0, 0.0, y], [0.0, 0.0, 1.0, z], [0.0, 0.0, 0.0, 1.0]], dtype=np.float32)
 
def normalize_vector(vector: np.ndarray) -> np.ndarray:
    length = float(np.linalg.norm(vector))
    if (length <= 0.0):
        return vector
 
    return vector / length
 
def look_at_matrix(eye: tuple[float, float, float], center: tuple[float, float, float], up: tuple[float, float, float]) -> np.ndarray:
    eye_vector = np.array(eye, dtype=np.float32)
    center_vector = np.array(center, dtype=np.float32)
    up_vector = np.array(up, dtype=np.float32)
    forward = normalize_vector(center_vector - eye_vector)
    side = normalize_vector(np.cross(forward, up_vector))
    camera_up = np.cross(side, forward)
    matrix = identity_matrix()
    matrix[0, 0] = side[0]
    matrix[0, 1] = side[1]
    matrix[0, 2] = side[2]
    matrix[0, 3] = -float(np.dot(side, eye_vector))
    matrix[1, 0] = camera_up[0]
    matrix[1, 1] = camera_up[1]
    matrix[1, 2] = camera_up[2]
    matrix[1, 3] = -float(np.dot(camera_up, eye_vector))
    matrix[2, 0] = -forward[0]
    matrix[2, 1] = -forward[1]
    matrix[2, 2] = -forward[2]
    matrix[2, 3] = float(np.dot(forward, eye_vector))
    return matrix
 
def perspective_matrix(fov_radians: float, aspect: float, near_plane: float, far_plane: float) -> np.ndarray:
    tangent = math.tan(fov_radians * 0.5)
    matrix = np.zeros((4, 4), dtype=np.float32)
    matrix[0, 0] = 1.0 / (aspect * tangent)
    matrix[1, 1] = 1.0 / tangent
    matrix[2, 2] = far_plane / (near_plane - far_plane)
    matrix[2, 3] = (far_plane * near_plane) / (near_plane - far_plane)
    matrix[3, 2] = -1.0
    matrix[1, 1] *= -1.0
    return matrix
 
class ModelWindow(mxvk.VK_Window):
    TITLE_TEXT = "MXVK Model Loader"
 
    def __init__(self, filename: str, path: str, title: str, width: int, height: int, fullscreen: bool, enable_vsync: bool):
        if (not path or path == "."):
            self.asset_root = EXAMPLE_DIR
        else:
            self.asset_root = Path(path).expanduser().resolve()
        self.data_directory = self.asset_root / "data"
        mxvk.set_default_shader_directory(str(self.data_directory))
        self.fallback_width = width
        self.fallback_height = height
        self.mouse_dragging = False
        self.auto_spin_enabled = True
        self.last_mouse_x = 0
        self.last_mouse_y = 0
        self.yaw_degrees = 0.0
        self.pitch_degrees = 0.0
        self.camera_distance = 5.35
        self.mouse_sensitivity = 0.35
        self.auto_spin_radians = 0.0
        self.elapsed_seconds = 0.0
        self.start_time = time.monotonic()
        self.last_frame_time = self.start_time
        self.model = None
        self._closed = False
        super().__init__(title, width, height, fullscreen, False, enable_vsync)
 
        try:
            self.set_clear_color(0.0, 0.0, 0.0, 1.0)
            self.set_font(str(self.data_directory / "font.ttf"), 48)
 
            if (filename):
                model_path = Path(filename).expanduser()
                material_path = model_path.with_suffix(".mtl")
            else:
                model_path = self.data_directory / "classic_tux.obj"
                material_path = self.data_directory / "classic_tux.mtl"
 
            model_vertex_shader = self.data_directory / "model.vert.spv"
            model_fragment_shader = self.data_directory / "model.frag.spv"
 
            self.model = mxvk.AbstractModel()
            self.model.load(self, str(model_path), str(material_path) if material_path.is_file() else "", str(model_path.parent), 1.0)
            self.model.set_shaders(self, str(model_vertex_shader), str(model_fragment_shader))
 
        except Exception:
            self.close()
            raise
 
    def close(self):
        if (self._closed):
            return
 
        self._closed = True
 
        try:
            self.wait_idle()
 
        finally:
            try:
                if (self.model is not None):
                    self.model.cleanup(self)
                    self.model = None
            finally:
                self.release()
 
    def event(self, event):
        if (event.key_down):
            if (event.key == mxvk.KEY_ESCAPE):
                self.request_exit()
                return
 
        if (event.mouse_button_down and event.button == mxvk.MOUSE_BUTTON_LEFT):
            self.mouse_dragging = True
            self.last_mouse_x = int(event.x)
            self.last_mouse_y = int(event.y)
            return
 
        if (event.mouse_button_up and event.button == mxvk.MOUSE_BUTTON_LEFT):
            self.mouse_dragging = False
            return
 
        if (event.mouse_motion and self.mouse_dragging):
            x = int(event.x)
            y = int(event.y)
            delta_x = x - self.last_mouse_x
            delta_y = y - self.last_mouse_y
            self.yaw_degrees += float(delta_x) * self.mouse_sensitivity
            self.pitch_degrees += float(delta_y) * self.mouse_sensitivity
            self.pitch_degrees = max(-55.0, min(55.0, self.pitch_degrees))
            self.last_mouse_x = x
            self.last_mouse_y = y
            return
 
        if (event.mouse_wheel):
            if (event.wheel_y != 0.0):
                delta = float(event.wheel_y)
            else:
                delta = float(event.wheel_ticks_y)
 
            self.camera_distance -= delta * 0.35
            self.camera_distance = max(2.0, min(10.0, self.camera_distance))
            return
 
    def on_swapchain_recreated(self):
        if (self.model is not None):
            self.model.resize(self)
 
    def proc(self):
        width, _ = self.swapchain_extent
 
        if (width <= 0):
            width = self.fallback_width
 
        dimensions = self.get_text_dimensions(self.TITLE_TEXT)
 
        if (dimensions is not None):
            text_width, _ = dimensions
            text_x = max(0, (int(width) - int(text_width)) // 2)
            self.print_text(self.TITLE_TEXT, text_x, 24, mxvk.Color(255, 255, 255, 255))
 
    def on_record_custom_rendering(self, command_buffer, image_index: int):
        if (self.model is None):
            return
 
        now = time.monotonic()
        delta_seconds = now - self.last_frame_time
 
        self.elapsed_seconds = now - self.start_time
        self.last_frame_time = now
 
        if (self.auto_spin_enabled):
            self.auto_spin_radians += delta_seconds * 0.55
 
        width, height = self.swapchain_extent
 
        if (height > 0):
            aspect = float(width) / float(height)
        else:
            aspect = 1.0
 
        yaw_radians = math.radians(self.yaw_degrees)
        pitch_radians = math.radians(self.pitch_degrees)
        camera_x = self.camera_distance * math.cos(pitch_radians) * math.sin(yaw_radians)
        camera_y = 0.35 + self.camera_distance * math.sin(pitch_radians)
        camera_z = self.camera_distance * math.cos(pitch_radians) * math.cos(yaw_radians)
        camera_position = (camera_x, camera_y, camera_z)
        view_matrix = look_at_matrix(camera_position, (0.0, 0.35, 0.0), (0.0, 1.0, 0.0))
        projection_matrix = perspective_matrix(math.radians(48.0), aspect, 0.1, 100.0)
        center_x, center_y, center_z = self.model.center_offset
        render_scale = float(self.model.render_scale) * 1.18
        model_matrix = rotation_y_matrix(self.auto_spin_radians)
        model_matrix = model_matrix @ scale_matrix(render_scale, render_scale, render_scale)
        model_matrix = model_matrix @ translation_matrix(center_x, center_y, center_z)
        uniforms = mxvk.ModelUniforms()
        uniforms.model = matrix_values(model_matrix)
        uniforms.view = matrix_values(view_matrix)
        uniforms.projection = matrix_values(projection_matrix)
        uniforms.effects = [
            self.elapsed_seconds,
            0.0,
            0.0,
            0.42,
        ]
        self.model.update_uniforms(image_index, uniforms)
        self.model.render(command_buffer, image_index, False)
 
def parse_resolution(value: str) -> tuple[int, int]:
    try:
        width_text, height_text = value.lower().split("x", 1)
        width = int(width_text)
        height = int(height_text)
 
    except ValueError as exception:
        raise argparse.ArgumentTypeError("resolution must use WIDTHxHEIGHT, for example 1280x720") from exception
 
    if (width <= 0 or height <= 0):
        raise argparse.ArgumentTypeError("resolution width and height must be greater than zero")
    return width, height
 
def parse_args():
    parser = argparse.ArgumentParser(description="MXVK textured Penguin Python example")
    parser.add_argument("filename", nargs="?", default="", help="optional OBJ or MXMOD model path")
    parser.add_argument("-i", "--input", dest="input_filename", default="", help="optional OBJ or MXMOD model path")
    parser.add_argument("-p", "--path", default=str(EXAMPLE_DIR), help="resource root containing the data directory")
    parser.add_argument("-r", "--resolution", type=parse_resolution, default=(1280, 720), metavar="WIDTHxHEIGHT", help="window resolution (default: 1280x720)")
    parser.add_argument("-f", "--fullscreen", action="store_true", help="start fullscreen")
    parser.add_argument("--enable-vsync", action="store_true", help="enable vertical synchronization")
    return parser.parse_args()
 
def main() -> int:
    args = parse_args()
    width, height = args.resolution
    if (args.input_filename):
        filename = args.input_filename
    else:
        filename = args.filename
    window = None
    try:
        window = ModelWindow(filename, args.path, "MXVK Model Test", width, height, args.fullscreen, args.enable_vsync)
        window.loop()
 
    except mxvk.MXVKError as exception:
        print(f"mxvk: Exception: {exception}", file=sys.stderr)
        return 1
    finally:
        if (window is not None):
            window.close()
    return 0
 
if (__name__ == "__main__"):
    raise SystemExit(main())