Use glsl_type::row_type and glsl_type::column type in arithmetic_result_type
This substantially clarifies the code for matching matrix types. It
also eliminates some uses of glsl_type member data.
diff --git a/ast_to_hir.cpp b/ast_to_hir.cpp
index cb746ed..740adb9 100644
--- a/ast_to_hir.cpp
+++ b/ast_to_hir.cpp
@@ -183,24 +183,39 @@
return (type_a == type_b) ? type_a : glsl_error_type;
} else {
if (type_a->is_matrix() && type_b->is_matrix()) {
- if (type_a->vector_elements == type_b->matrix_rows) {
- return glsl_type::get_instance(type_a->base_type,
- type_b->matrix_rows,
- type_a->vector_elements);
+ /* Matrix multiply. The columns of A must match the rows of B. Given
+ * the other previously tested constraints, this means the vector type
+ * of a row from A must be the same as the vector type of a column from
+ * B.
+ */
+ if (type_a->row_type() == type_b->column_type()) {
+ /* The resulting matrix has the number of columns of matrix B and
+ * the number of rows of matrix A. We get the row count of A by
+ * looking at the size of a vector that makes up a column. The
+ * transpose (size of a row) is done for B.
+ */
+ return
+ glsl_type::get_instance(type_a->base_type,
+ type_a->column_type()->vector_elements,
+ type_b->row_type()->vector_elements);
}
} else if (type_a->is_matrix()) {
/* A is a matrix and B is a column vector. Columns of A must match
- * rows of B.
+ * rows of B. Given the other previously tested constraints, this
+ * means the vector type of a row from A must be the same as the
+ * vector the type of B.
*/
- if (type_a->vector_elements == type_b->vector_elements)
+ if (type_a->row_type() == type_b)
return type_b;
} else {
assert(type_b->is_matrix());
- /* A is a row vector and B is a matrix. Columns of A must match
- * rows of B.
+ /* A is a row vector and B is a matrix. Columns of A must match rows
+ * of B. Given the other previously tested constraints, this means
+ * the type of A must be the same as the vector type of a column from
+ * B.
*/
- if (type_a->vector_elements == type_b->matrix_rows)
+ if (type_a == type_b->column_type())
return type_a;
}
}