Fix alignment computation for `std140` uniforms

Fixes #55

I was incorrectly computing alignment as `elementSize * elementAlignment`, rounded up to a power of two (which works out to be `elementSize` squared), when I should have been using `elementSize * elementCount`, rounded up to a power of two.

2 files changed, 58 insertions, 0 deletions

diff --git a/tests/reflection/gh-55.glsl b/tests/reflection/gh-55.glsl
new file mode 100644
index 000000000..4ced68c9e
--- /dev/null
+++ b/tests/reflection/gh-55.glsl
@@ -0,0 +1,13 @@
+//TEST(smoke):SIMPLE:-profile ps_4_0 -target reflection-json
+
+// Confirm fix for GitHub issue #55
+
+layout(set = 0, binding = 0)
+uniform PerFrameCB
+{
+	vec2 offset;
+	vec2 scale;
+};
+
+void main()
+{}
diff --git a/tests/reflection/gh-55.glsl.expected b/tests/reflection/gh-55.glsl.expected
new file mode 100644
index 000000000..8cdebdcd8
--- /dev/null
+++ b/tests/reflection/gh-55.glsl.expected
@@ -0,0 +1,45 @@
+result code = 0
+standard error = {
+}
+standard output = {
+{
+    "parameters": [
+        {
+            "name": "PerFrameCB",
+            "binding": {"kind": "descriptorTableSlot", "index": 0},
+            "type": {
+                "kind": "constantBuffer",
+                "elementType": {
+                    "kind": "struct",
+                    "fields": [
+                        {
+                            "name": "offset",
+                            "type": {
+                                "kind": "vector",
+                                "elementCount": 2,
+                                "elementType": {
+                                    "kind": "scalar",
+                                    "scalarType": "float32"
+                                }
+                            },
+                            "binding": {"kind": "uniform", "offset": 0, "size": 8}
+                        },
+                        {
+                            "name": "scale",
+                            "type": {
+                                "kind": "vector",
+                                "elementCount": 2,
+                                "elementType": {
+                                    "kind": "scalar",
+                                    "scalarType": "float32"
+                                }
+                            },
+                            "binding": {"kind": "uniform", "offset": 8, "size": 8}
+                        }
+                    ]
+                }
+            }
+        }
+    ]
+}
+}