From: Mikko Rasa <tdb@tdb.fi>
Date: Sun, 7 Nov 2021 14:12:11 +0000 (+0200)
Subject: Fix GLSL matrix construction from individual elements
X-Git-Url: http://git.tdb.fi/?p=libs%2Fgl.git;a=commitdiff_plain;h=e1dacd64ec555d7344d32a9c11e785f1dc3d0929

Fix GLSL matrix construction from individual elements
---

diff --git a/source/glsl/resolve.cpp b/source/glsl/resolve.cpp
index eb99bec2..406d7780 100644
--- a/source/glsl/resolve.cpp
+++ b/source/glsl/resolve.cpp
@@ -972,6 +972,11 @@ void ExpressionResolver::visit_constructor(FunctionCall &call)
 		{
 			unsigned column_count = basic->size&0xFFFF;
 			unsigned row_count = basic->size>>16;
+
+			vector<RefPtr<Expression> > columns;
+			columns.reserve(column_count);
+			bool changed_columns = false;
+
 			if(call.arguments.size()==1)
 			{
 				/* A matrix can be constructed from a single element or another
@@ -994,8 +999,6 @@ void ExpressionResolver::visit_constructor(FunctionCall &call)
 					current_block->body.insert(insert_point, temporary);
 
 					// Create expressions to build each column.
-					vector<RefPtr<Expression> > columns;
-					columns.reserve(column_count);
 					for(unsigned j=0; j<column_count; ++j)
 					{
 						RefPtr<VariableReference> ref = new VariableReference;
@@ -1016,13 +1019,7 @@ void ExpressionResolver::visit_constructor(FunctionCall &call)
 							truncate_vector(columns.back(), row_count);
 					}
 
-					call.arguments.resize(column_count);
-					copy(columns.begin(), columns.end(), call.arguments.begin());
-
-					/* Let VariableResolver process the new nodes and finish
-					resolving the constructor on the next pass. */
-					r_any_resolved = true;
-					return;
+					changed_columns = true;
 				}
 				else
 					return;
@@ -1031,9 +1028,6 @@ void ExpressionResolver::visit_constructor(FunctionCall &call)
 			{
 				/* Construct a matrix from individual components in column-major
 				order.  Arguments must align at column boundaries. */
-				vector<RefPtr<Expression> > columns;
-				columns.reserve(column_count);
-
 				vector<RefPtr<Expression> > column_args;
 				column_args.reserve(row_count);
 				unsigned column_component_count = 0;
@@ -1067,11 +1061,24 @@ void ExpressionResolver::visit_constructor(FunctionCall &call)
 						else if(column_component_count>row_count)
 							// Argument alignment mismatch.
 							return;
+
+						changed_columns = true;
 					}
 				}
 			}
 			else
 				return;
+
+			if(changed_columns)
+			{
+				call.arguments.resize(column_count);
+				copy(columns.begin(), columns.end(), call.arguments.begin());
+
+				/* Let VariableResolver process the new nodes and finish
+				resolving the constructor on the next pass. */
+				r_any_resolved = true;
+				return;
+			}
 		}
 		else
 			return;
diff --git a/tests/glsl/matrix_from_elements.glsl b/tests/glsl/matrix_from_elements.glsl
new file mode 100644
index 00000000..42b16556
--- /dev/null
+++ b/tests/glsl/matrix_from_elements.glsl
@@ -0,0 +1,31 @@
+uniform Transform
+{
+	vec3 translation;
+	float rotation;
+};
+
+#pragma MSP stage(vertex)
+layout(location=0) in vec2 position;
+void main()
+{
+	float c = cos(rotation);
+	float s = sin(rotation);
+	mat3 m = mat3(c, s, 0.0, -s, c, 0.0, translation);
+	gl_Position = vec4((m*vec3(position, 1.0)).xy, 0.0, 1.0);
+}
+
+/* Expected output: vertex
+layout(binding=48) uniform Transform
+{
+	vec3 translation;
+	float rotation;
+};
+layout(location=0) in vec2 position;
+void main()
+{
+	float c = cos(rotation);
+	float s = sin(rotation);
+
+	gl_Position = vec4((mat3(vec3(c, s, 0.0), vec3(-s, c, 0.0), translation)*vec3(position, 1.0)).xy, 0.0, 1.0);
+}
+*/