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// Copyright 2014 Citra Emulator Project
// Licensed under GPLv2 or any later version
// Refer to the license.txt file included.
#pragma once
#include "common/common_types.h"
namespace VideoCore {
// 8x8 Z-Order coordinate from 2D coordinates
static inline u32 MortonInterleave(u32 x, u32 y) {
static const u32 xlut[] = {0x00, 0x01, 0x04, 0x05, 0x10, 0x11, 0x14, 0x15};
static const u32 ylut[] = {0x00, 0x02, 0x08, 0x0a, 0x20, 0x22, 0x28, 0x2a};
return xlut[x % 8] + ylut[y % 8];
}
/**
* Calculates the offset of the position of the pixel in Morton order
*/
static inline u32 GetMortonOffset(u32 x, u32 y, u32 bytes_per_pixel) {
// Images are split into 8x8 tiles. Each tile is composed of four 4x4 subtiles each
// of which is composed of four 2x2 subtiles each of which is composed of four texels.
// Each structure is embedded into the next-bigger one in a diagonal pattern, e.g.
// texels are laid out in a 2x2 subtile like this:
// 2 3
// 0 1
//
// The full 8x8 tile has the texels arranged like this:
//
// 42 43 46 47 58 59 62 63
// 40 41 44 45 56 57 60 61
// 34 35 38 39 50 51 54 55
// 32 33 36 37 48 49 52 53
// 10 11 14 15 26 27 30 31
// 08 09 12 13 24 25 28 29
// 02 03 06 07 18 19 22 23
// 00 01 04 05 16 17 20 21
//
// This pattern is what's called Z-order curve, or Morton order.
const unsigned int block_height = 8;
const unsigned int coarse_x = x & ~7;
u32 i = VideoCore::MortonInterleave(x, y);
const unsigned int offset = coarse_x * block_height;
return (i + offset) * bytes_per_pixel;
}
} // namespace
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