【发布时间】：2016-04-27 18:21:28
【问题描述】：
您好，我正在尝试使用 XNA 制作一个绘图程序，并且我尽可能地遵循了此处的指南：How to create Paint-like app with XNA? 到目前为止一切都很好，但是有一个问题：the drawn rectangles dont connect together to form a line.我没有想法，我将不胜感激提供的任何帮助。下面是我的代码。还请查看随附的图片以更好地理解。
using Microsoft.Xna.Framework;
using Microsoft.Xna.Framework.Graphics;
using Microsoft.Xna.Framework.Input;
using System;
using System.Collections.Generic;
namespace ProfAnas
{
/// <summary>
/// This is the main type for your game.
/// </summary>
public class Game1 : Game
{
GraphicsDeviceManager graphics;
SpriteBatch spriteBatch;
Texture2D canvas;
Vector2 brushPos;
public Game1()
{
graphics = new GraphicsDeviceManager(this);
Content.RootDirectory = "Content";
graphics.PreferredBackBufferWidth = 1920; // set this value to the desired width of your window
graphics.PreferredBackBufferHeight = 1080; // set this value to the desired height of your window
graphics.ApplyChanges();
}
/// <summary>
/// Allows the game to perform any initialization it needs to before starting to run.
/// This is where it can query for any required services and load any non-graphic
/// related content. Calling base.Initialize will enumerate through any components
/// and initialize them as well.
/// </summary>
protected override void Initialize()
{
// TODO: Add your initialization logic here
base.Initialize();
Color[] pixel = new Color[1920 * 1080];
for (int i = 0; i < pixel.Length; i++)
{
pixel[i] = Color.White;
}
pixel[1919] = Color.Red;
spriteBatch = new SpriteBatch(GraphicsDevice);
canvas = new Texture2D(this.GraphicsDevice, 1920, 1080);
canvas.SetData<Color>(pixel);
}
/// <summary>
/// LoadContent will be called once per game and is the place to load
/// all of your content.
/// </summary>
protected override void LoadContent()
{
// Create a new SpriteBatch, which can be used to draw textures.
spriteBatch = new SpriteBatch(GraphicsDevice);
// TODO: use this.Content to load your game content here
}
/// <summary>
/// UnloadContent will be called once per game and is the place to unload
/// game-specific content.
/// </summary>
protected override void UnloadContent()
{
// TODO: Unload any non ContentManager content here
}
/// <summary>
/// Allows the game to run logic such as updating the world,
/// checking for collisions, gathering input, and playing audio.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Update(GameTime gameTime)
{
MouseState state = Mouse.GetState();
Color[] pixel = new Color[1920 * 1080];
canvas.GetData<Color>(pixel);
if (state.LeftButton == ButtonState.Pressed)
{
brushPos.X = state.X;
brushPos.Y = state.Y;
double piOn4 = Math.PI / 4;
int xComponent;
int yComponent;
int screenWidth = 1920;
int screenHeight = 1080;
int regionXHalfed = (int)Math.Ceiling((10.0 * Math.Cos(piOn4) + 30.0 * Math.Cos(piOn4))/2);
int regionYHalfed = (int)Math.Ceiling((10.0 * Math.Sin(piOn4) + 30.0 * Math.Sin(piOn4))/2);
double angle;
double centerToBoundary;
double pixelToCenter;
List<int> boundedPixel = new List<int>();
for (int row=(state.Y-regionYHalfed); row < (state.Y + regionYHalfed); row++)
{
for (int column= (state.X - regionXHalfed); column < (state.X + regionXHalfed); column++)
{
xComponent=column - state.X+1;
yComponent=row - state.Y+1;
if (xComponent == 0)
{
pixelToCenter = Math.Sqrt((double)xComponent*xComponent + (double)yComponent*yComponent);
if (Math.Abs(pixelToCenter) <= 5*Math.Sqrt(2))
{
boundedPixel.Add(((row) * screenWidth + column) + 1);
}
continue;
}
angle=Math.Atan( (double)yComponent / (double)xComponent);
if (angle>= (piOn4 - Math.Atan(1.0/3)) && angle<= (piOn4 + Math.Atan(1.0/3)))
{
centerToBoundary = 15 / Math.Cos(angle - piOn4);
pixelToCenter= xComponent / Math.Cos(angle);
if( Math.Abs(pixelToCenter) <= Math.Abs(centerToBoundary))
{
boundedPixel.Add(((row)* screenWidth + column)+1);
}
}
if (angle >= (piOn4 + Math.Atan(1.0 / 3)) && angle <= Math.PI/2)
{
centerToBoundary = 5 / Math.Cos(angle + piOn4);
pixelToCenter = xComponent / Math.Cos(angle);
if (Math.Abs(pixelToCenter) <= Math.Abs(centerToBoundary))
{
boundedPixel.Add(((row) * screenWidth + column) + 1);
}
}
if (angle >= 0.0 && angle <= (piOn4 - Math.Atan(1.0 / 3)))
{
centerToBoundary = 5 / Math.Cos(angle + piOn4);
pixelToCenter = xComponent / Math.Cos(angle);
if (Math.Abs(pixelToCenter) <= Math.Abs(centerToBoundary))
{
boundedPixel.Add(((row) * screenWidth + column) + 1);
}
}
if (angle >= -Math.PI / 2 && angle <= 0.0)
{
centerToBoundary = 5 / Math.Cos(angle + piOn4);
pixelToCenter = xComponent / Math.Cos(angle);
if (Math.Abs(pixelToCenter) <= Math.Abs(centerToBoundary))
{
boundedPixel.Add(((row) * screenWidth + column) + 1);
}
}
}
}
foreach (int i in boundedPixel)
{
if(i>=0)
pixel[i] = Color.Red;
}
}
canvas.SetData<Color>(pixel);
// TODO: Add your update logic here
base.Update(gameTime);
}
/// <summary>
/// This is called when the game should draw itself.
/// </summary>
/// <param name="gameTime">Provides a snapshot of timing values.</param>
protected override void Draw(GameTime gameTime)
{
GraphicsDevice.Clear(Color.CornflowerBlue);
// TODO: Add your drawing code here
spriteBatch.Begin();
spriteBatch.Draw(canvas, new Vector2(0, 0));
spriteBatch.End();
base.Draw(gameTime);
}
}
}
谢谢你:)
【问题讨论】：
-
发生这种情况是因为鼠标在帧之间移动的距离大于“画笔”的宽度。您遵循的示例根本没有考虑这种情况。你必须尝试一些更高级的东西。