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: Ic0b2bfc685b8aeb92d1d4401174a819279386ea3
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/5221
Commit-Queue: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
This commit is contained in:
Li Hao 2019-03-18 12:26:07 +00:00 committed by Commit Bot service account
parent 991ab98f11
commit fef613365a
1 changed files with 17 additions and 4 deletions

View File

@ -82,12 +82,25 @@ 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
// max(attrib.offset + sizeof(attrib) for each attrib)
// but the stride must NOT be 0, so we made up it with
// max(attrib.offset + sizeof(attrib) for each attrib)
uint32_t max_stride = 0;
for (uint32_t attribIndex : IterateBitSet(attributesSetMask)) {
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,
static_cast<uint32_t>(VertexFormatSize(attrib.format)) + 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;