Increase precision of 8 bit textures
Only use the upper 8 bits of the 16 bit fields when reading
and outputting 8 bit values in order to get exact
representations of x/255 for each possible 8 bit value.
Bug: swiftshader:122
Bug: b/129523279
Change-Id: I0cd54eb325c24f2fc5a53f12a0b90696024ca9d1
Tests: dEQP-VK.memory.pipeline_barrier.all.*
Reviewed-on: https://swiftshader-review.googlesource.com/c/SwiftShader/+/33028
Tested-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Chris Forbes <chrisforbes@google.com>
Kokoro-Presubmit: kokoro <noreply+kokoro@google.com>
diff --git a/src/Pipeline/SamplerCore.cpp b/src/Pipeline/SamplerCore.cpp
index 0dd30b9..2dc6add 100644
--- a/src/Pipeline/SamplerCore.cpp
+++ b/src/Pipeline/SamplerCore.cpp
@@ -178,6 +178,17 @@
c.z *= Float4(1.0f / 0x7F00);
c.w *= Float4(1.0f / 0x7F00);
break;
+ case VK_FORMAT_R8_UNORM:
+ case VK_FORMAT_R8G8_UNORM:
+ case VK_FORMAT_R8G8B8A8_UNORM:
+ case VK_FORMAT_A8B8G8R8_UNORM_PACK32:
+ case VK_FORMAT_B8G8R8A8_SRGB:
+ case VK_FORMAT_R8G8B8A8_SRGB:
+ c.x *= Float4(1.0f / 0xFF00u);
+ c.y *= Float4(1.0f / 0xFF00u);
+ c.z *= Float4(1.0f / 0xFF00u);
+ c.w *= Float4(1.0f / 0xFF00u);
+ break;
default:
for (int component = 0; component < textureComponentCount(); component++)
{
@@ -218,6 +229,17 @@
c.z = Float4(cs.z) * Float4(1.0f / 0x7F00);
c.w = Float4(cs.w) * Float4(1.0f / 0x7F00);
break;
+ case VK_FORMAT_R8_UNORM:
+ case VK_FORMAT_R8G8_UNORM:
+ case VK_FORMAT_R8G8B8A8_UNORM:
+ case VK_FORMAT_A8B8G8R8_UNORM_PACK32:
+ case VK_FORMAT_B8G8R8A8_SRGB:
+ case VK_FORMAT_R8G8B8A8_SRGB:
+ c.x = Float4(As<UShort4>(cs.x)) * Float4(1.0f / 0xFF00u);
+ c.y = Float4(As<UShort4>(cs.y)) * Float4(1.0f / 0xFF00u);
+ c.z = Float4(As<UShort4>(cs.z)) * Float4(1.0f / 0xFF00u);
+ c.w = Float4(As<UShort4>(cs.w)) * Float4(1.0f / 0xFF00u);
+ break;
default:
for(int component = 0; component < textureComponentCount(); component++)
{
@@ -1379,10 +1401,10 @@
c.x = As<Short4>(UnpackHigh(c.x, c.y));
c.y = c.z;
c.w = c.x;
- c.z = UnpackLow(As<Byte8>(c.z), As<Byte8>(c.z));
- c.y = UnpackHigh(As<Byte8>(c.y), As<Byte8>(c.y));
- c.x = UnpackLow(As<Byte8>(c.x), As<Byte8>(c.x));
- c.w = UnpackHigh(As<Byte8>(c.w), As<Byte8>(c.w));
+ c.z = UnpackLow(As<Byte8>(Short4(0)), As<Byte8>(c.z));
+ c.y = UnpackHigh(As<Byte8>(Short4(0)), As<Byte8>(c.y));
+ c.x = UnpackLow(As<Byte8>(Short4(0)), As<Byte8>(c.x));
+ c.w = UnpackHigh(As<Byte8>(Short4(0)), As<Byte8>(c.w));
break;
case VK_FORMAT_R8G8B8A8_UNORM:
case VK_FORMAT_R8G8B8A8_SINT:
@@ -1392,10 +1414,10 @@
c.x = As<Short4>(UnpackLow(c.x, c.y));
c.y = c.x;
c.w = c.z;
- c.x = UnpackLow(As<Byte8>(c.x), As<Byte8>(c.x));
- c.y = UnpackHigh(As<Byte8>(c.y), As<Byte8>(c.y));
- c.z = UnpackLow(As<Byte8>(c.z), As<Byte8>(c.z));
- c.w = UnpackHigh(As<Byte8>(c.w), As<Byte8>(c.w));
+ c.x = UnpackLow(As<Byte8>(Short4(0)), As<Byte8>(c.x));
+ c.y = UnpackHigh(As<Byte8>(Short4(0)), As<Byte8>(c.y));
+ c.z = UnpackLow(As<Byte8>(Short4(0)), As<Byte8>(c.z));
+ c.w = UnpackHigh(As<Byte8>(Short4(0)), As<Byte8>(c.w));
// Propagate sign bit
if(state.textureFormat == VK_FORMAT_R8G8B8A8_SINT)
{
@@ -1404,16 +1426,6 @@
c.z >>= 8;
c.w >>= 8;
}
-
- if (state.textureFormat == VK_FORMAT_R8G8B8A8_SNORM)
- {
- // TODO: avoid populating the low bits at all.
- c.x &= Short4(0xFF00u);
- c.y &= Short4(0xFF00u);
- c.z &= Short4(0xFF00u);
- c.w &= Short4(0xFF00u);
- }
-
break;
case VK_FORMAT_R8G8B8A8_UINT:
c.z = As<Short4>(UnpackHigh(c.x, c.y));
@@ -1439,9 +1451,6 @@
switch(state.textureFormat)
{
case VK_FORMAT_R8G8_UNORM:
- c.y = (c.x & Short4(0xFF00u)) | As<Short4>(As<UShort4>(c.x) >> 8);
- c.x = (c.x & Short4(0x00FFu)) | (c.x << 8);
- break;
case VK_FORMAT_R8G8_SNORM:
c.y = (c.x & Short4(0xFF00u));
c.x = (c.x << 8);
@@ -1481,6 +1490,7 @@
}
break;
case VK_FORMAT_R8_SNORM:
+ case VK_FORMAT_R8_UNORM:
// TODO: avoid populating the low bits at all.
c.x = Unpack(As<Byte4>(c0));
c.x &= Short4(0xFF00u);
