skia2/tests/sksl/shared/Clockwise.metal
Brian Salomon 943108b0b2 Don't key progams/pipelines on origin.
SkSL language features that are origin sensitive now use a uniform
to conditionally flip their result rather than generating different
code.

Previously we would insert a "rt height" uniform if sk_FragCoord needed
to be flipped. sk_FragCoord,y was implemented as "realFragCoord.y" or
"rtHeight - realFragCoord.y" depending on SkSL::ProgramSettings::fFlipY.

Now we instead use a two component vector rtFlip and sk_FragCoord.y is
always "rtFlip.x + rtFlip.y*realFragCoord.y". We configure rtFlip as
either (0, 1) or (rtHeight, -1). sk_Clockwise and dFdy simiarly use
rtFlip.y to emit code that always works with either origin.

Bug: skia:12037

Change-Id: I7a09d0caac60a58d72b76645ff31bcabde4086b6
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/414796
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Reviewed-by: Ethan Nicholas <ethannicholas@google.com>
2021-07-06 18:08:06 +00:00

18 lines
564 B
Metal

#include <metal_stdlib>
#include <simd/simd.h>
using namespace metal;
struct Inputs {
};
struct Outputs {
float4 sk_FragColor [[color(0)]];
};
struct sksl_synthetic_uniforms {
float2 u_skRTFlip;
};
fragment Outputs fragmentMain(Inputs _in [[stage_in]], constant sksl_synthetic_uniforms& _anonInterface0 [[buffer(1)]], bool _frontFacing [[front_facing]], float4 _fragCoord [[position]]) {
Outputs _out;
(void)_out;
_out.sk_FragColor = float4(float((_anonInterface0.u_skRTFlip.y < 0 ? _frontFacing : !_frontFacing) ? 1 : -1));
return _out;
}