You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
87 lines
3.6 KiB
87 lines
3.6 KiB
/* |
|
* 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 |
|
.balign 0 |
|
|
|
.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 |
|
|
|
|
|
|
|
|