| /* |
| * Copyright © 2014 Intel Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the "Software"), |
| * to deal in the Software without restriction, including without limitation |
| * the rights to use, copy, modify, merge, publish, distribute, sublicense, |
| * and/or sell copies of the Software, and to permit persons to whom the |
| * Software is furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice (including the next |
| * paragraph) shall be included in all copies or substantial portions of the |
| * Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL |
| * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING |
| * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER |
| * DEALINGS IN THE SOFTWARE. |
| */ |
| |
| /** |
| * \file lower_vertex_id.cpp |
| * |
| * There exists hardware, such as i965, that does not implement the OpenGL |
| * semantic for gl_VertexID. Instead, that hardware does not include the |
| * value of basevertex in the gl_VertexID value. To implement the OpenGL |
| * semantic, we'll have to convert gl_Vertex_ID to |
| * gl_VertexIDMESA+gl_BaseVertexMESA. |
| */ |
| |
| #include "glsl_symbol_table.h" |
| #include "ir_hierarchical_visitor.h" |
| #include "ir.h" |
| #include "ir_builder.h" |
| #include "linker.h" |
| #include "program/prog_statevars.h" |
| #include "builtin_functions.h" |
| #include "main/mtypes.h" |
| |
| namespace { |
| |
| class lower_vertex_id_visitor : public ir_hierarchical_visitor { |
| public: |
| explicit lower_vertex_id_visitor(ir_function_signature *main_sig, |
| exec_list *ir_list) |
| : progress(false), VertexID(NULL), gl_VertexID(NULL), |
| gl_BaseVertex(NULL), main_sig(main_sig), ir_list(ir_list) |
| { |
| foreach_in_list(ir_instruction, ir, ir_list) { |
| ir_variable *const var = ir->as_variable(); |
| |
| if (var != NULL && var->data.mode == ir_var_system_value && |
| var->data.location == SYSTEM_VALUE_BASE_VERTEX) { |
| gl_BaseVertex = var; |
| break; |
| } |
| } |
| } |
| |
| virtual ir_visitor_status visit(ir_dereference_variable *); |
| |
| bool progress; |
| |
| private: |
| ir_variable *VertexID; |
| ir_variable *gl_VertexID; |
| ir_variable *gl_BaseVertex; |
| |
| ir_function_signature *main_sig; |
| exec_list *ir_list; |
| }; |
| |
| } /* anonymous namespace */ |
| |
| ir_visitor_status |
| lower_vertex_id_visitor::visit(ir_dereference_variable *ir) |
| { |
| if (ir->var->data.mode != ir_var_system_value || |
| ir->var->data.location != SYSTEM_VALUE_VERTEX_ID) |
| return visit_continue; |
| |
| if (VertexID == NULL) { |
| const glsl_type *const int_t = glsl_type::int_type; |
| void *const mem_ctx = ralloc_parent(ir); |
| |
| VertexID = new(mem_ctx) ir_variable(int_t, "__VertexID", |
| ir_var_temporary); |
| ir_list->push_head(VertexID); |
| |
| gl_VertexID = new(mem_ctx) ir_variable(int_t, "gl_VertexIDMESA", |
| ir_var_system_value); |
| gl_VertexID->data.how_declared = ir_var_declared_implicitly; |
| gl_VertexID->data.read_only = true; |
| gl_VertexID->data.location = SYSTEM_VALUE_VERTEX_ID_ZERO_BASE; |
| gl_VertexID->data.explicit_location = true; |
| gl_VertexID->data.explicit_index = 0; |
| ir_list->push_head(gl_VertexID); |
| |
| if (gl_BaseVertex == NULL) { |
| gl_BaseVertex = new(mem_ctx) ir_variable(int_t, "gl_BaseVertex", |
| ir_var_system_value); |
| gl_BaseVertex->data.how_declared = ir_var_hidden; |
| gl_BaseVertex->data.read_only = true; |
| gl_BaseVertex->data.location = SYSTEM_VALUE_BASE_VERTEX; |
| gl_BaseVertex->data.explicit_location = true; |
| gl_BaseVertex->data.explicit_index = 0; |
| ir_list->push_head(gl_BaseVertex); |
| } |
| |
| ir_instruction *const inst = |
| ir_builder::assign(VertexID, |
| ir_builder::add(gl_VertexID, gl_BaseVertex)); |
| |
| main_sig->body.push_head(inst); |
| } |
| |
| ir->var = VertexID; |
| progress = true; |
| |
| return visit_continue; |
| } |
| |
| bool |
| lower_vertex_id(gl_linked_shader *shader) |
| { |
| /* gl_VertexID only exists in the vertex shader. |
| */ |
| if (shader->Stage != MESA_SHADER_VERTEX) |
| return false; |
| |
| ir_function_signature *const main_sig = |
| _mesa_get_main_function_signature(shader->symbols); |
| if (main_sig == NULL) { |
| assert(main_sig != NULL); |
| return false; |
| } |
| |
| lower_vertex_id_visitor v(main_sig, shader->ir); |
| |
| v.run(shader->ir); |
| |
| return v.progress; |
| } |