From b0dc3aff2c73f2a1b65406dcb7fe73c95b9485ed Mon Sep 17 00:00:00 2001 From: Jason Fielder Date: Thu, 14 Apr 2022 11:47:52 +0200 Subject: Metal: GLSL shader compatibility 3rd pass Undefined behaviour for divergent control-flow fixes, replacement for partial vector references, and resolution of a number of calculation precision issues occuring on macOS. Authored by Apple: Michael Parkin-White Ref: T96261 Reviewed By: fclem Differential Revision: https://developer.blender.org/D14437 --- .../blender/gpu/shaders/material/gpu_shader_material_hash.glsl | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'source/blender/gpu/shaders/material') diff --git a/source/blender/gpu/shaders/material/gpu_shader_material_hash.glsl b/source/blender/gpu/shaders/material/gpu_shader_material_hash.glsl index cb798047791..32d61f06a65 100644 --- a/source/blender/gpu/shaders/material/gpu_shader_material_hash.glsl +++ b/source/blender/gpu/shaders/material/gpu_shader_material_hash.glsl @@ -209,10 +209,12 @@ vec3 hash_vec4_to_vec3(vec4 k) float integer_noise(int n) { - int nn; - n = (n + 1013) & 0x7fffffff; - n = (n >> 13) ^ n; - nn = (n * (n * n * 60493 + 19990303) + 1376312589) & 0x7fffffff; + /* Integer bit-shifts for these calculations can cause precision problems on macOS. + * Using uint resolves these issues. */ + uint nn; + nn = (uint(n) + 1013u) & 0x7fffffffu; + nn = (nn >> 13u) ^ nn; + nn = (uint(nn * (nn * nn * 60493u + 19990303u)) + 1376312589u) & 0x7fffffffu; return 0.5 * (float(nn) / 1073741824.0); } -- cgit v1.2.3