diff options
Diffstat (limited to 'libpixelflinger/arch-arm64/col32cb16blend.S')
| -rw-r--r-- | libpixelflinger/arch-arm64/col32cb16blend.S | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/libpixelflinger/arch-arm64/col32cb16blend.S b/libpixelflinger/arch-arm64/col32cb16blend.S new file mode 100644 index 0000000..18a01fd --- /dev/null +++ b/libpixelflinger/arch-arm64/col32cb16blend.S @@ -0,0 +1,87 @@ +/* + * Copyright (C) 2013 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + .text + .align + + .global scanline_col32cb16blend_arm64 + +// +// This function alpha blends a fixed color into a destination scanline, using +// the formula: +// +// d = s + (((a + (a >> 7)) * d) >> 8) +// +// where d is the destination pixel, +// s is the source color, +// a is the alpha channel of the source color. +// + +// x0 = destination buffer pointer +// w1 = color value +// w2 = count + + +scanline_col32cb16blend_arm64: + + lsr w5, w1, #24 // shift down alpha + mov w9, #0xff // create mask + add w5, w5, w5, lsr #7 // add in top bit + mov w4, #256 // create #0x100 + sub w5, w4, w5 // invert alpha + and w10, w1, #0xff // extract red + and w12, w9, w1, lsr #8 // extract green + and w4, w9, w1, lsr #16 // extract blue + lsl w10, w10, #5 // prescale red + lsl w12, w12, #6 // prescale green + lsl w4, w4, #5 // prescale blue + lsr w9, w9, #2 // create dest green mask + +1: + ldrh w8, [x0] // load dest pixel + subs w2, w2, #1 // decrement loop counter + lsr w6, w8, #11 // extract dest red + and w7, w9, w8, lsr #5 // extract dest green + and w8, w8, #0x1f // extract dest blue + + madd w6, w6, w5, w10 // dest red * alpha + src red + madd w7, w7, w5, w12 // dest green * alpha + src green + madd w8, w8, w5, w4 // dest blue * alpha + src blue + + lsr w6, w6, #8 // shift down red + lsr w7, w7, #8 // shift down green + lsl w6, w6, #11 // shift red into 565 + orr w6, w6, w7, lsl #5 // shift green into 565 + orr w6, w6, w8, lsr #8 // shift blue into 565 + + strh w6, [x0], #2 // store pixel to dest, update ptr + b.ne 1b // if count != 0, loop + + ret + + + |