Implement seamless cubemap sampling.
The addressing is offset by 1 to account for the border. Note that this
could be avoided by locking at (0, 0) instead of (-1, -1) instead, but
then negative address offsets have to be allowed and this complicates
the subsequent calculations and only unsigned extension from 32-bit to
64-bit is typically for free during memory accesses.
Change-Id: I5fb843401d440a9d77d141782124a9c260765830
Reviewed-on: https://swiftshader-review.googlesource.com/13289
Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <nicolascapens@google.com>
diff --git a/src/Shader/SamplerCore.cpp b/src/Shader/SamplerCore.cpp
index 1c97628..942cf87 100644
--- a/src/Shader/SamplerCore.cpp
+++ b/src/Shader/SamplerCore.cpp
@@ -316,7 +316,8 @@
{
// FIXME: YUV and sRGB are not supported by the floating point path
bool forceFloatFiltering = state.highPrecisionFiltering && !state.sRGB && !hasYuvFormat() && (state.textureFilter != FILTER_POINT);
- if(hasFloatTexture() || hasUnnormalizedIntegerTexture() || forceFloatFiltering) // FIXME: Mostly identical to integer sampling
+ bool seamlessCube = (state.addressingModeU == ADDRESSING_SEAMLESS);
+ if(hasFloatTexture() || hasUnnormalizedIntegerTexture() || forceFloatFiltering || seamlessCube) // FIXME: Mostly identical to integer sampling
{
Float4 uuuu = u;
Float4 vvvv = v;
@@ -1666,7 +1667,7 @@
M = Max(Max(absX, absY), absZ);
- // U = xMajor ? (neg ^ -z) : (zMajor & neg) ^ x)
+ // U = xMajor ? (neg ^ -z) : ((zMajor & neg) ^ x)
U = As<Float4>((xMajor & (n ^ As<Int4>(-z))) | (~xMajor & ((zMajor & n) ^ As<Int4>(x))));
// V = !yMajor ? -y : (n ^ z)
@@ -1695,6 +1696,8 @@
break;
case ADDRESSING_TEXELFETCH:
break;
+ case AddressingMode::ADDRESSING_SEAMLESS:
+ ASSERT(false); // Cube sampling doesn't support offset.
default:
ASSERT(false);
}
@@ -2388,11 +2391,20 @@
const int oneBits = 0x3F7FFFFF; // Value just under 1.0f
const int twoBits = 0x3FFFFFFF; // Value just under 2.0f
+ bool pointFilter = state.textureFilter == FILTER_POINT ||
+ state.textureFilter == FILTER_MIN_POINT_MAG_LINEAR ||
+ state.textureFilter == FILTER_MIN_LINEAR_MAG_POINT;
+
Float4 coord = uvw;
+
switch(addressingMode)
{
case ADDRESSING_CLAMP:
case ADDRESSING_BORDER:
+ case ADDRESSING_SEAMLESS:
+ // Linear filtering of cube doesn't require clamping because the coordinates
+ // are already in [0, 1] range and numerical imprecision is tolerated.
+ if(addressingMode != ADDRESSING_SEAMLESS || pointFilter)
{
Float4 one = As<Float4>(Int4(oneBits));
coord = Min(Max(coord, Float4(0.0f)), one);
@@ -2448,12 +2460,19 @@
xyz0 += As<Int4>(texOffset);
}
+ if(addressingMode == ADDRESSING_SEAMLESS)
+ {
+ xyz0 += Int4(1);
+ }
+
xyz1 = xyz0 - filter; // Increment
if(function.option == Offset)
{
switch(addressingMode)
{
+ case ADDRESSING_SEAMLESS:
+ ASSERT(false); // Cube sampling doesn't support offset.
case ADDRESSING_MIRROR:
case ADDRESSING_MIRRORONCE:
case ADDRESSING_BORDER:
@@ -2473,6 +2492,8 @@
{
switch(addressingMode)
{
+ case ADDRESSING_SEAMLESS:
+ break;
case ADDRESSING_MIRROR:
case ADDRESSING_MIRRORONCE:
case ADDRESSING_BORDER:
