glsl: Add helper methods to glsl_type for dealing with images.

Add predicates to query if a GLSL type is or contains an image.
Rename sampler_coordinate_components() to coordinate_components().

v2: Use assert instead of unreachable.
v3: No need to use a separate code-path for images in
    coordinate_components() after merging image and sampler fields in
    the glsl_type structure.

Reviewed-by: Paul Berry <stereotype441@gmail.com>

src/glsl/builtin_functions.cpp

@@ -3549,7 +3549,7 @@ builtin_builder::_texture(ir_texture_opcode opcode,
    ir_texture *tex = new(mem_ctx) ir_texture(opcode);
    tex->set_sampler(var_ref(s), return_type);
 
-   const int coord_size = sampler_type->sampler_coordinate_components();
+   const int coord_size = sampler_type->coordinate_components();
 
    if (coord_size == coord_type->vector_elements) {
       tex->coordinate = var_ref(P);

src/glsl/glsl_types.cpp

@@ -226,6 +226,21 @@ glsl_type::sampler_index() const
    }
 }
 
+bool
+glsl_type::contains_image() const
+{
+   if (this->is_array()) {
+      return this->fields.array->contains_image();
+   } else if (this->is_record()) {
+      for (unsigned int i = 0; i < this->length; i++) {
+	 if (this->fields.structure[i].type->contains_image())
+	    return true;
+      }
+      return false;
+   } else {
+      return this->is_image();
+   }
+}
 
 const glsl_type *glsl_type::get_base_type() const
 {
@@ -955,10 +970,8 @@ glsl_type::count_attribute_slots() const
 }
 
 int
-glsl_type::sampler_coordinate_components() const
+glsl_type::coordinate_components() const
 {
-   assert(is_sampler());
-
    int size;
 
    switch (sampler_dimensionality) {

src/glsl/glsl_types.h

@@ -403,6 +403,20 @@ struct glsl_type {
     */
    gl_texture_index sampler_index() const;
 
+   /**
+    * Query whether or not type is an image, or for struct and array
+    * types, contains an image.
+    */
+   bool contains_image() const;
+
+   /**
+    * Query whether or not a type is an image
+    */
+   bool is_image() const
+   {
+      return base_type == GLSL_TYPE_IMAGE;
+   }
+
    /**
     * Query whether or not a type is an array
     */
@@ -533,7 +547,8 @@ struct glsl_type {
    }
 
    /**
-    * Return the number of coordinate components needed for this sampler type.
+    * Return the number of coordinate components needed for this
+    * sampler or image type.
     *
     * This is based purely on the sampler's dimensionality.  For example, this
     * returns 1 for sampler1D, and 3 for sampler2DArray.
@@ -542,7 +557,7 @@ struct glsl_type {
     * a texturing built-in function, since those pack additional values (such
     * as the shadow comparitor or projector) into the coordinate type.
     */
-   int sampler_coordinate_components() const;
+   int coordinate_components() const;
 
    /**
     * Compare a record type against another record type.

src/glsl/tests/sampler_types_test.cpp

@@ -47,7 +47,7 @@ TEST(sampler_types, TYPE)                                   \
    EXPECT_EQ(DATA_TYPE, type->sampler_type);                \
    ARR;                                                     \
    SHAD;                                                    \
-   EXPECT_EQ(COMPS, type->sampler_coordinate_components()); \
+   EXPECT_EQ(COMPS, type->coordinate_components());         \
 }
 
 T( sampler1D,        GLSL_SAMPLER_DIM_1D,   GLSL_TYPE_FLOAT, NONARRAY, COLOR,  1)