问题
I am building a game with dialog boxes, and I would like to be able to procedurally generate textures for the boxes, in a very similar style to that of the Final Fantasy Series (think like Final Fantasy VII). Here is a code snippet of what I have so far:
public class DialogBox
{
public Rectangle BoxArea { get; set; }
public List<Color> BoxColors { get; set; }
public List<Color> BorderColors { get; set; }
public int BorderThickness { get; set; }
public int BorderRadius { get; set; }
private Texture2D texture;
public void CreateBackdrop(ref GraphicsDevice graphics)
{
texture = new Texture2D(graphics,
BoxArea.Width,
BoxArea.Height,
true,
SurfaceFormat.Color);
Color[] color = new Color[texture.Width * texture.Height];
for(int x = 0; x < texture.Width; x++)
{
for(int y = 0; y < texture.Height; y++)
{
switch(BoxColors.Count)
{
case 4:
Color leftColor = Color.Lerp(BoxColor[0], BoxColor[1], (y / (texture.Height - 1)));
Color rightColor = Color.Lerp(BoxColor[2], BoxColor[3], (y / (texture.Height - 1)));
color[x + y * texture.Width] = Color.Lerp(leftColor,
RightColor,
(x / (texture.Width - 1)));
break;
case 2:
color[x + y * texture.Width] = Color.Lerp(BoxColors[0],
BoxColors[1],
(x / (texture.Width - 1)));
break;
default:
color[x + y * texture.Width];
break;
}
}
}
texture.SetData<Color>(color);
}
}
What I am looking for is the following:
- 4-way gradient color (implemented)
- Rounded Rectangle
- Border with gradient
Any help would be greatly appreciated.
I figured out the rectangle via this question.
回答1:
I figured out what I was having trouble with; calculating the corner arcs. What I figured out was that one could use distance from a point to understand the way to draw the border, rather than using mathematics to calculate the points within a circle. Below I have posted the code to generate the rounded rectangle.
public Texture2D CreateRoundedRectangleTexture(GraphicsDevice graphics, int width, int height, int borderThickness, int borderRadius, int borderShadow, List<Color> backgroundColors, List<Color> borderColors, float initialShadowIntensity, float finalShadowIntensity)
{
if (backgroundColors == null || backgroundColors.Count == 0) throw new ArgumentException("Must define at least one background color (up to four).");
if (borderColors == null || borderColors.Count == 0) throw new ArgumentException("Must define at least one border color (up to three).");
if (borderRadius < 1) throw new ArgumentException("Must define a border radius (rounds off edges).");
if (borderThickness < 1) throw new ArgumentException("Must define border thikness.");
if (borderThickness + borderRadius > height / 2 || borderThickness + borderRadius > width / 2) throw new ArgumentException("Border will be too thick and/or rounded to fit on the texture.");
if (borderShadow > borderRadius) throw new ArgumentException("Border shadow must be lesser in magnitude than the border radius (suggeted: shadow <= 0.25 * radius).");
Texture2D texture = new Texture2D(graphics, width, height, false, SurfaceFormat.Color);
Color[] color = new Color[width * height];
for (int x = 0; x < texture.Width; x++)
{
for (int y = 0; y < texture.Height; y++)
{
switch (backgroundColors.Count)
{
case 4:
Color leftColor0 = Color.Lerp(backgroundColors[0], backgroundColors[1], ((float)y / (width - 1)));
Color rightColor0 = Color.Lerp(backgroundColors[2], backgroundColors[3], ((float)y / (height - 1)));
color[x + width * y] = Color.Lerp(leftColor0, rightColor0, ((float)x / (width - 1)));
break;
case 3:
Color leftColor1 = Color.Lerp(backgroundColors[0], backgroundColors[1], ((float)y / (width - 1)));
Color rightColor1 = Color.Lerp(backgroundColors[1], backgroundColors[2], ((float)y / (height - 1)));
color[x + width * y] = Color.Lerp(leftColor1, rightColor1, ((float)x / (width - 1)));
break;
case 2:
color[x + width * y] = Color.Lerp(backgroundColors[0], backgroundColors[1], ((float)x / (width - 1)));
break;
default:
color[x + width * y] = backgroundColors[0];
break;
}
color[x + width * y] = ColorBorder(x, y, width, height, borderThickness, borderRadius, borderShadow, color[x + width * y], borderColors, initialShadowIntensity, finalShadowIntensity);
}
}
texture.SetData<Color>(color);
return texture;
}
private Color ColorBorder(int x, int y, int width, int height, int borderThickness, int borderRadius, int borderShadow, Color initialColor, List<Color> borderColors, float initialShadowIntensity, float finalShadowIntensity)
{
Rectangle internalRectangle = new Rectangle((borderThickness + borderRadius), (borderThickness + borderRadius), width - 2 * (borderThickness + borderRadius), height - 2 * (borderThickness + borderRadius));
if (internalRectangle.Contains(x, y)) return initialColor;
Vector2 origin = Vector2.Zero;
Vector2 point = new Vector2(x, y);
if (x < borderThickness + borderRadius)
{
if (y < borderRadius + borderThickness)
origin = new Vector2(borderRadius + borderThickness, borderRadius + borderThickness);
else if (y > height - (borderRadius + borderThickness))
origin = new Vector2(borderRadius + borderThickness, height - (borderRadius + borderThickness));
else
origin = new Vector2(borderRadius + borderThickness, y);
}
else if (x > width - (borderRadius + borderThickness))
{
if (y < borderRadius + borderThickness)
origin = new Vector2(width - (borderRadius + borderThickness), borderRadius + borderThickness);
else if (y > height - (borderRadius + borderThickness))
origin = new Vector2(width - (borderRadius + borderThickness), height - (borderRadius + borderThickness));
else
origin = new Vector2(width - (borderRadius + borderThickness), y);
}
else
{
if (y < borderRadius + borderThickness)
origin = new Vector2(x, borderRadius + borderThickness);
else if (y > height - (borderRadius + borderThickness))
origin = new Vector2(x, height - (borderRadius + borderThickness));
}
if (!origin.Equals(Vector2.Zero))
{
float distance = Vector2.Distance(point, origin);
if (distance > borderRadius + borderThickness + 1)
{
return Color.Transparent;
}
else if (distance > borderRadius + 1)
{
if (borderColors.Count > 2)
{
float modNum = distance - borderRadius;
if (modNum < borderThickness / 2)
{
return Color.Lerp(borderColors[2], borderColors[1], (float)((modNum) / (borderThickness / 2.0)));
}
else
{
return Color.Lerp(borderColors[1], borderColors[0], (float)((modNum - (borderThickness / 2.0)) / (borderThickness / 2.0)));
}
}
if (borderColors.Count > 0)
return borderColors[0];
}
else if (distance > borderRadius - borderShadow + 1)
{
float mod = (distance - (borderRadius - borderShadow)) / borderShadow;
float shadowDiff = initialShadowIntensity - finalShadowIntensity;
return DarkenColor(initialColor, ((shadowDiff * mod) + finalShadowIntensity));
}
}
return initialColor;
}
private Color DarkenColor(Color color, float shadowIntensity)
{
return Color.Lerp(color, Color.Black, shadowIntensity);
}
With all of the code above, this is the result:
来源：https://stackoverflow.com/questions/17217411/create-rounded-rectangle-texture2d