| 16998 | } |
| 16999 | |
| 17000 | function clipImage( x0, y0, x1, y1, x2, y2, u0, v0, u1, v1, u2, v2, image ) { |
| 17001 | |
| 17002 | // http://extremelysatisfactorytotalitarianism.com/blog/?p=2120 |
| 17003 | |
| 17004 | var a, b, c, d, e, f, det, idet, |
| 17005 | width = image.width - 1, |
| 17006 | height = image.height - 1; |
| 17007 | |
| 17008 | u0 *= width; v0 *= height; |
| 17009 | u1 *= width; v1 *= height; |
| 17010 | u2 *= width; v2 *= height; |
| 17011 | |
| 17012 | x1 -= x0; y1 -= y0; |
| 17013 | x2 -= x0; y2 -= y0; |
| 17014 | |
| 17015 | u1 -= u0; v1 -= v0; |
| 17016 | u2 -= u0; v2 -= v0; |
| 17017 | |
| 17018 | det = u1 * v2 - u2 * v1; |
| 17019 | |
| 17020 | idet = 1 / det; |
| 17021 | |
| 17022 | a = ( v2 * x1 - v1 * x2 ) * idet; |
| 17023 | b = ( v2 * y1 - v1 * y2 ) * idet; |
| 17024 | c = ( u1 * x2 - u2 * x1 ) * idet; |
| 17025 | d = ( u1 * y2 - u2 * y1 ) * idet; |
| 17026 | |
| 17027 | e = x0 - a * u0 - c * v0; |
| 17028 | f = y0 - b * u0 - d * v0; |
| 17029 | |
| 17030 | _context.save(); |
| 17031 | _context.transform( a, b, c, d, e, f ); |
| 17032 | _context.clip(); |
| 17033 | _context.drawImage( image, 0, 0 ); |
| 17034 | _context.restore(); |
| 17035 | |
| 17036 | } |
| 17037 | |
| 17038 | function getGradientTexture( color1, color2, color3, color4 ) { |
| 17039 | |