Home | History | Annotate | Download | only in glsl 
      1 /*
      2  * Copyright  2010 Intel Corporation
      3  *
      4  * Permission is hereby granted, free of charge, to any person obtaining a
      5  * copy of this software and associated documentation files (the "Software"),
      6  * to deal in the Software without restriction, including without limitation
      7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
      8  * and/or sell copies of the Software, and to permit persons to whom the
      9  * Software is furnished to do so, subject to the following conditions:
     10  *
     11  * The above copyright notice and this permission notice (including the next
     12  * paragraph) shall be included in all copies or substantial portions of the
     13  * Software.
     14  *
     15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
     19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
     20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
     21  * DEALINGS IN THE SOFTWARE.
     22  */
     23 
     24 #include "ir.h"
     25 #include "glsl_parser_extras.h"
     26 #include "ast.h"
     27 #include "compiler/glsl_types.h"
     28 
     29 ir_rvalue *
     30 _mesa_ast_field_selection_to_hir(const ast_expression *expr,
     31 				 exec_list *instructions,
     32 				 struct _mesa_glsl_parse_state *state)
     33 {
     34    void *ctx = state;
     35    ir_rvalue *result = NULL;
     36    ir_rvalue *op;
     37 
     38    op = expr->subexpressions[0]->hir(instructions, state);
     39 
     40    /* There are two kinds of field selection.  There is the selection of a
     41     * specific field from a structure, and there is the selection of a
     42     * swizzle / mask from a vector.  Which is which is determined entirely
     43     * by the base type of the thing to which the field selection operator is
     44     * being applied.
     45     */
     46    YYLTYPE loc = expr->get_location();
     47    if (op->type->is_error()) {
     48       /* silently propagate the error */
     49    } else if (op->type->base_type == GLSL_TYPE_STRUCT
     50               || op->type->base_type == GLSL_TYPE_INTERFACE) {
     51       result = new(ctx) ir_dereference_record(op,
     52 					      expr->primary_expression.identifier);
     53 
     54       if (result->type->is_error()) {
     55 	 _mesa_glsl_error(& loc, state, "cannot access field `%s' of "
     56 			  "structure",
     57 			  expr->primary_expression.identifier);
     58       }
     59    } else if (op->type->is_vector() ||
     60               (state->has_420pack() && op->type->is_scalar())) {
     61       ir_swizzle *swiz = ir_swizzle::create(op,
     62 					    expr->primary_expression.identifier,
     63 					    op->type->vector_elements);
     64       if (swiz != NULL) {
     65 	 result = swiz;
     66       } else {
     67 	 /* FINISHME: Logging of error messages should be moved into
     68 	  * FINISHME: ir_swizzle::create.  This allows the generation of more
     69 	  * FINISHME: specific error messages.
     70 	  */
     71 	 _mesa_glsl_error(& loc, state, "invalid swizzle / mask `%s'",
     72 			  expr->primary_expression.identifier);
     73       }
     74    } else {
     75       _mesa_glsl_error(& loc, state, "cannot access field `%s' of "
     76 		       "non-structure / non-vector",
     77 		       expr->primary_expression.identifier);
     78    }
     79 
     80    return result ? result : ir_rvalue::error_value(ctx);
     81 }
     82