Vladimir Sukharev
25 lines
884 B
Kotlin
Vendored
25 lines
884 B
Kotlin
Vendored
import kotlin.test.*
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object RGBA {
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fun packFast(r: Int, g: Int, b: Int, a: Int) = (r shl 0) or (g shl 8) or (b shl 16) or (a shl 24)
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fun getFastR(v: Int): Int = (v ushr 0) and 0xFF
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fun getFastG(v: Int): Int = (v ushr 8) and 0xFF
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fun getFastB(v: Int): Int = (v ushr 16) and 0xFF
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fun getFastA(v: Int): Int = (v ushr 24) and 0xFF
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fun premultiplyFastInt(v: Int): Int {
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val A = getFastA(v) + 1
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val RB = (((v and 0x00FF00FF) * A) ushr 8) and 0x00FF00FF
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val G = (((v and 0x0000FF00) * A) ushr 8) and 0x0000FF00
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return (v and 0x00FFFFFF.inv()) or RB or G
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}
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}
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fun box(): String {
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val source = listOf(0xFFFFFFFF.toInt(), 0xFFFFFF77.toInt(), 0x777777FF.toInt(), 0x77777777.toInt())
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val expect = listOf(-1, -137, 2000107383, 2000107319)
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assertEquals(expect, source.map { RGBA.premultiplyFastInt(it) })
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return "OK"
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} |