glsl: Add is_basis function

Determines whether it's a basis vector, i.e., a vector with one element
equal to 1 and all other elements equal to 0.

Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 22 insertions, 4 deletions

diff --git a/src/glsl/ir.h b/src/glsl/ir.h
index a3f9f058863..55535b2f5ce 100644
--- a/src/glsl/ir.h
+++ b/src/glsl/ir.h
@@ -201,7 +201,8 @@ public:
     * for vector and scalar types that have all elements set to the value
     * zero (or \c false for booleans).
     *
-    * \sa ir_constant::has_value, ir_rvalue::is_one, ir_rvalue::is_negative_one
+    * \sa ir_constant::has_value, ir_rvalue::is_one, ir_rvalue::is_negative_one,
+    *     ir_constant::is_basis
     */
    virtual bool is_zero() const;
 
@@ -213,7 +214,8 @@ public:
     * for vector and scalar types that have all elements set to the value
     * one (or \c true for booleans).
     *
-    * \sa ir_constant::has_value, ir_rvalue::is_zero, ir_rvalue::is_negative_one
+    * \sa ir_constant::has_value, ir_rvalue::is_zero, ir_rvalue::is_negative_one,
+    *     ir_constant::is_basis
     */
    virtual bool is_one() const;
 
@@ -223,12 +225,27 @@ public:
     * The base implementation of this function always returns \c false.  The
     * \c ir_constant class over-rides this function to return \c true \b only
     * for vector and scalar types that have all elements set to the value
-    * negative one.  For boolean times, the result is always \c false.
+    * negative one.  For boolean types, the result is always \c false.
     *
     * \sa ir_constant::has_value, ir_rvalue::is_zero, ir_rvalue::is_one
+    *     ir_constant::is_basis
     */
    virtual bool is_negative_one() const;
 
+   /**
+    * Determine if an r-value is a basis vector
+    *
+    * The base implementation of this function always returns \c false.  The
+    * \c ir_constant class over-rides this function to return \c true \b only
+    * for vector and scalar types that have one element set to the value one,
+    * and the other elements set to the value zero.  For boolean types, the
+    * result is always \c false.
+    *
+    * \sa ir_constant::has_value, ir_rvalue::is_zero, ir_rvalue::is_one,
+    *     is_constant::is_negative_one
+    */
+   virtual bool is_basis() const;
+
 
    /**
     * Return a generic value of error_type.
@@ -1743,13 +1760,14 @@ public:
     * Determine whether a constant has the same value as another constant
     *
     * \sa ir_constant::is_zero, ir_constant::is_one,
-    * ir_constant::is_negative_one
+    * ir_constant::is_negative_one, ir_constant::is_basis
     */
    bool has_value(const ir_constant *) const;
 
    virtual bool is_zero() const;
    virtual bool is_one() const;
    virtual bool is_negative_one() const;
+   virtual bool is_basis() const;
 
    /**
     * Value of the constant.