func()

in shiny/iconvg/upgrade.go [549:648]

• 92 lines of code
• 22 McCabe index (conditional complexity)

func (u *upgrader) emitFill(v1 buffer) (newV1 buffer, retErr error) {
	switch c := u.creg[u.fill]; c.typ {
	case ColorTypeRGBA:
		if validAlphaPremulColor(c.rgba) {
			if !u.hasRegsSel7 || (u.regsSel7 != c.rgba) {
				u.hasRegsSel7, u.regsSel7 = true, c.rgba
				v1 = append(v1, 0x57, // FFV1 Set REGS[SEL+7].hi32.
					c.rgba.R, c.rgba.G, c.rgba.B, c.rgba.A)
			}
			v1 = append(v1, 0x87) // FFV1 Fill (flat color) with REGS[SEL+7].

		} else if (c.rgba.A == 0) && (c.rgba.B&0x80 != 0) {
			nStops := int(c.rgba.R & 63)
			cBase := int(c.rgba.G & 63)
			nBase := int(c.rgba.B & 63)
			if nStops < 2 {
				return nil, errInvalidColor
			} else if nStops > 17 {
				return nil, errUnsupportedUpgrade
			}

			v1 = append(v1, 0x70|uint8(nStops-2)) // FFV1 SEL -= N; Set REGS[SEL+1 .. SEL+1+N].
			for i := 0; i < nStops; i++ {
				if stopOffset := u.nreg[(nBase+i)&63]; stopOffset <= 0 {
					v1 = append(v1, 0x00, 0x00, 0x00, 0x00)
				} else if stopOffset < 1 {
					u := uint32(stopOffset * 0x10000)
					v1 = append(v1, uint8(u>>0), uint8(u>>8), uint8(u>>16), uint8(u>>24))
				} else {
					v1 = append(v1, 0x00, 0x00, 0x01, 0x00)
				}

				if stopColor := u.creg[(cBase+i)&63]; stopColor.typ != ColorTypeRGBA {
					return nil, errUnsupportedUpgrade
				} else {
					v1 = append(v1,
						stopColor.rgba.R,
						stopColor.rgba.G,
						stopColor.rgba.B,
						stopColor.rgba.A,
					)
				}
			}

			nMatrixElements := 0
			if c.rgba.B&0x40 == 0 {
				v1 = append(v1, 0x91, // FFV1 Fill (linear gradient) with REGS[SEL+1 .. SEL+1+N].
					(c.rgba.G&0xc0)|uint8(nStops-2))
				nMatrixElements = 3
			} else {
				v1 = append(v1, 0xa1, // FFV1 Fill (radial gradient) with REGS[SEL+1 .. SEL+1+N].
					(c.rgba.G&0xc0)|uint8(nStops-2))
				nMatrixElements = 6
			}
			for i := 0; i < nMatrixElements; i++ {
				u := math.Float32bits(u.nreg[(nBase+i-6)&63])
				v1 = append(v1, uint8(u>>0), uint8(u>>8), uint8(u>>16), uint8(u>>24))
			}

			v1 = append(v1, 0x36, // FFV1 SEL += N.
				uint8(nStops))
		} else {
			return nil, errInvalidColor
		}

	case ColorTypePaletteIndex:
		if c.paletteIndex < 7 {
			v1 = append(v1, 0x88+c.paletteIndex) // FFV1 Fill (flat color) with REGS[SEL+8+N].
		} else {
			v1 = append(v1, 0x56, // FFV1 Set REGS[SEL+6].hi32.
				0x80|c.paletteIndex, 0, 0, 0,
				0x86) // FFV1 Fill (flat color) with REGS[SEL+6].
		}

	case ColorTypeBlend:
		if c.color0.typ == ColorTypeRGBA {
			v1 = append(v1, 0x53, // FFV1 Set REGS[SEL+3].hi32.
				c.color0.rgba.R, c.color0.rgba.G, c.color0.rgba.B, c.color0.rgba.A)
		}
		if c.color1.typ == ColorTypeRGBA {
			v1 = append(v1, 0x54, // FFV1 Set REGS[SEL+4].hi32.
				c.color1.rgba.R, c.color1.rgba.G, c.color1.rgba.B, c.color1.rgba.A)
		}
		v1 = append(v1, 0x55, // FFV1 Set REGS[SEL+5].hi32.
			c.blend)
		if c.color0.typ == ColorTypeRGBA {
			v1 = append(v1, 0xfe)
		} else {
			v1 = append(v1, 0x80|c.color0.paletteIndex)
		}
		if c.color1.typ == ColorTypeRGBA {
			v1 = append(v1, 0xff)
		} else {
			v1 = append(v1, 0x80|c.color1.paletteIndex)
		}
		v1 = append(v1, 0, 0x85) // FFV1 Fill (flat color) with REGS[SEL+5].
	}

	return v1, nil
}