Unity实现文本转贴图

public Color[] GetPixels(int x, int y, int blockWidth, int blockHeight);

public void SetPixel(int x, int y, Color color);

public Texture2D TextToTexture(
        Font font,
        string text,
        int textureWidth, int textureHeight,
        int drawOffsetX, int drawOffsetY,
        int textGap, int spaceGap, int rowHeight,
        Color textColor,
        Color backgroundColor)
    {
        // 创建返回的Texture
        var textTexture = new Texture2D(textureWidth, textureHeight, TextureFormat.ARGB32, true);
        Color[] emptyColor = new Color[textureWidth * textureHeight];
        for (int i = 0; i < emptyColor.Length; i++)
        {
            emptyColor[i] = backgroundColor;
        }
        textTexture.SetPixels(emptyColor);

        // 字体贴图不可读，需要创建一个新的可读的
        var fontTexture = (Texture2D)font.material.mainTexture;
        var readableFontTexture = new Texture2D(fontTexture.width, fontTexture.height, fontTexture.format, fontTexture.mipmapCount, true);
        Graphics.CopyTexture(fontTexture, readableFontTexture);

        // 调整偏移量
        var originalDrawOffsetX = drawOffsetX;// 记录一下，换行用
        drawOffsetY = textureHeight - drawOffsetY - rowHeight;// 从上方开始画

        // 逐个字符绘制
        foreach (var @char in text.ToCharArray())
        {
            if (@char == ' ')
            {
                drawOffsetX += spaceGap;
                continue;
            }

            if (@char == '\n')
            {
                // 换行
                drawOffsetX = originalDrawOffsetX;
                drawOffsetY -= rowHeight;

                continue;
            }


            int charWidth, charHeight;// 字符宽高
            Color[] charColor;// 字符颜色，数组内颜色的顺序为从左至右，从下至上

            font.GetCharacterInfo(@char, out CharacterInfo info);
            if (info.uvTopLeft.x < info.uvBottomRight.x)// 处理被垂直翻转的字符
            {
                charWidth = info.glyphWidth;
                charHeight = info.glyphHeight;

                charColor = readableFontTexture.GetPixels(
                    (int)(readableFontTexture.width * info.uvTopLeft.x),
                    (int)(readableFontTexture.height * info.uvTopLeft.y),
                    charWidth, charHeight);

                for (int j = 0; j < charHeight; j++)
                {
                    for (int i = 0; i < charWidth; i++)
                    {
                        if (charColor[j * charWidth + i].a != 0)
                        {
                            textTexture.SetPixel(
                                drawOffsetX + i,
                                drawOffsetY + charHeight - j,// 从上往下画，把字符颠倒过来
                                textColor);
                        }
                    }
                }
            }
            else// 处理被顺时针旋转90度的字符
            {
                charWidth = info.glyphHeight;
                charHeight = info.glyphWidth;

                charColor = readableFontTexture.GetPixels(
                    (int)(readableFontTexture.width * info.uvBottomRight.x),
                    (int)(readableFontTexture.height * info.uvBottomRight.y),
                    charWidth, charHeight);

                for (int j = 0; j < charHeight; j++)
                {
                    for (int i = 0; i < charWidth; i++)
                    {
                        if (charColor[j * charWidth + i].a != 0)
                        {
                            // 旋转
                            textTexture.SetPixel(
                                drawOffsetX + charHeight - j,
                                drawOffsetY + i,
                                textColor);
                        }
                    }
                }
            }

            // 更新偏移
            drawOffsetX += charWidth + textGap;
        }

        textTexture.Apply();
        return textTexture;
    }