A few options are provided via macros.
As default, cglm requires types to be aligned. Alignment requirements:
vec3: 8 byte vec4: 16 byte mat4: 16 byte versor: 16 byte
By starting v0.4.5 cglm provides an option to disable alignment requirement. To enable this option define CGLM_ALL_UNALIGNED macro before all headers. You can define it in Xcode, Visual Studio (or other IDEs) or you can also prefer to define it in build system. If you use pre-compiled verisons then you have to compile cglm with CGLM_ALL_UNALIGNED macro.
- VERY VERY IMPORTANT: If you use cglm in multiple projects and
those projects are depends on each other, thenALWAYS or NEVER USE CGLM_ALL_UNALIGNED macro in linked projects
if you do not know what you are doing. Because a cglm header included via ‘project A’ may force types to be aligned and another cglm header included via ‘project B’ may not require alignment. In this case cglm functions will read from and write to INVALID MEMORY LOCATIONs.
ALWAYS USE SAME CONFIGURATION / OPTION for cglm if you have multiple projects.
For instance if you set CGLM_ALL_UNALIGNED in a project then set it in other projects too
SSE and SSE2 Shuffle Option¶
_mm_shuffle_ps generates shufps instruction even if registers are same. You can force it to generate pshufd instruction by defining CGLM_USE_INT_DOMAIN macro. As default it is not defined.
SSE3 and SSE4 Dot Product Options¶
You have to extra options for dot product: CGLM_SSE4_DOT and CGLM_SSE3_DOT.
- If SSE4 is enabled then you can define CGLM_SSE4_DOT to force cglm to use _mm_dp_ps instruction.
- If SSE3 is enabled then you can define CGLM_SSE3_DOT to force cglm to use _mm_hadd_ps instructions.
otherwise cglm will use custom cglm’s hadd functions which are optimized too.