Reland "Fix zero stride in input state for Metal validation"

Update stride value to max(attribute.offset + sizeof(attribute) for
each attribute) when input stride is 0 in Metal backend

BUG=dawn:75
TEST=dawn_end2end_tests

Change-Id: I449532807f7fba1bca22106f2c38d496b8cbf01f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/7020
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
Commit-Queue: Hao Li <hao.x.li@intel.com>
This commit is contained in:
Li Hao 2019-05-07 07:06:59 +00:00 committed by Commit Bot service account
parent 8804bc541e
commit f112ceca34
1 changed files with 15 additions and 4 deletions

View File

@ -421,12 +421,23 @@ namespace dawn_native { namespace metal {
auto layoutDesc = [MTLVertexBufferLayoutDescriptor new];
if (info.stride == 0) {
// For MTLVertexStepFunctionConstant, the stepRate must be 0,
// but the stride must NOT be 0, so I made up a value (256).
// TODO(cwallez@chromium.org): the made up value will need to be at least
// but the stride must NOT be 0, so we made up it with
// max(attrib.offset + sizeof(attrib) for each attrib)
size_t max_stride = 0;
for (uint32_t attribIndex : IterateBitSet(GetAttributesSetMask())) {
const VertexAttributeDescriptor& attrib = GetAttribute(attribIndex);
// Only use the attributes that use the current input
if (attrib.inputSlot != info.inputSlot) {
continue;
}
max_stride = std::max(max_stride,
VertexFormatSize(attrib.format) + size_t(attrib.offset));
}
layoutDesc.stepFunction = MTLVertexStepFunctionConstant;
layoutDesc.stepRate = 0;
layoutDesc.stride = 256;
// Metal requires the stride must be a multiple of 4 bytes, align it with next
// multiple of 4 if it's not.
layoutDesc.stride = Align(max_stride, 4);
} else {
layoutDesc.stepFunction = InputStepModeFunction(info.stepMode);
layoutDesc.stepRate = 1;