The purpose of this guidebook is to lay down principles and guidelines for how to write code and work together at Our Machinery.
Each guideline in this document is identified by a unique identifier (OMG-META-1) as well as
a name (Guidelines are identified by unique identifiers). Names may change, but identifiers are
permanent and can be used to permanently and uniquely refer to a specific guideline.
| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
| // reference https://registry.khronos.org/OpenGL/extensions/EXT/EXT_texture_shared_exponent.txt | |
| const RGB9E5_MANTISSA_BITS = 9; | |
| const RGB9E5_EXP_BIAS = 15; | |
| const RGB9E5_MAX_VALID_BIASED_EXP = 31; | |
| const MAX_RGB9E5_EXP = ( RGB9E5_MAX_VALID_BIASED_EXP - RGB9E5_EXP_BIAS ); | |
| const RGB9E5_MANTISSA_VALUES = ( 1 << RGB9E5_MANTISSA_BITS ); | |
| const MAX_RGB9E5_MANTISSA = ( RGB9E5_MANTISSA_VALUES - 1 ); | |
| const MAX_RGB9E5 = ( ( MAX_RGB9E5_MANTISSA ) / RGB9E5_MANTISSA_VALUES * ( 1 << MAX_RGB9E5_EXP ) ); |
| #pragma once | |
| #include <limits> | |
| #include <cassert> | |
| #include <stdexcept> | |
| #define MORTON_CODE_MAX_LEVEL 32 | |
| #define UINT8 unsigned char | |
| #define UINT32 unsigned int |
| // The MIT License (MIT) | |
| // Copyright (c) 2018 cmf028 | |
| // Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: | |
| // The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. | |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH |
| // cofactor matrix. drop-in replacement for the traditional transpose(inverse(m)) normal matrix calculation. | |
| // this is a substantial performance improvement. | |
| // short form found via shadertoy: https://www.shadertoy.com/view/3s33z | |
| mat3 cofactor(mat4 m) { | |
| return mat3( | |
| cross(m[1].xyz, m[2].xyz), | |
| cross(m[2].xyz, m[0].xyz), | |
| cross(m[0].xyz, m[1].xyz) | |
| ); | |
| } |
| // these matrices are for left-handed coordinate systems, with depth mapped to [1;0] | |
| // the derivation for other matrices is analogous | |
| // to get a perspective matrix with reversed z, simply swap the near and far plane | |
| glm::mat4 perspectiveFovReverseZLH_ZO(float fov, float width, float height, float zNear, float zFar) { | |
| return glm::perspectiveFovLH_ZO(fov, width, height, zFar, zNear); | |
| }; | |
| // now let zFar go towards infinity | |
| glm::mat4 infinitePerspectiveFovReverseZLH_ZO(float fov, float width, float height, float zNear) { |
List of freely available resources to study computer graphics programming.
This method stores a full TBN frame using just 3 bytes per vertex (plus a bitfield), instead of the traditional 28 bytes (normal: vec3, tangent: vec4). It leverages octahedral encoding for normals and a rotation angle for tangent reconstruction.
Storing both glm::vec3 normal and glm::vec4 tangent is costly. Since the bitangent can be reconstructed via a cross product, we only need: