framework/randomshaders/rsgExpressionGenerator.cpp

   1 /*-------------------------------------------------------------------------
   2  * drawElements Quality Program Random Shader Generator
   3  * ----------------------------------------------------
   4  *
   5  * Copyright 2014 The Android Open Source Project
   6  *
   7  * Licensed under the Apache License, Version 2.0 (the "License");
   8  * you may not use this file except in compliance with the License.
   9  * You may obtain a copy of the License at
  10  *
  11  *      http://www.apache.org/licenses/LICENSE-2.0
  12  *
  13  * Unless required by applicable law or agreed to in writing, software
  14  * distributed under the License is distributed on an "AS IS" BASIS,
  15  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  16  * See the License for the specific language governing permissions and
  17  * limitations under the License.
  18  *
  19  *//*!
  20  * \file
  21  * \brief Expression generator.
  22  *//*--------------------------------------------------------------------*/
  23
  24 #include "rsgExpressionGenerator.hpp"
  25
  26 namespace rsg
  27 {
  28
  29 ExpressionGenerator::ExpressionGenerator (GeneratorState& state)
  30         : m_state(state)
  31 {
  32 }
  33
  34 ExpressionGenerator::~ExpressionGenerator (void)
  35 {
  36 }
  37
  38 Expression* ExpressionGenerator::generate (const ValueRange& valueRange, int initialDepth)
  39 {
  40         // Create root
  41         m_state.setExpressionDepth(initialDepth);
  42         Expression* root = Expression::createRandom(m_state, valueRange);
  43
  44         try
  45         {
  46                 // Generate full expression
  47                 generate(root);
  48         }
  49         catch (const std::exception&)
  50         {
  51                 delete root;
  52                 m_expressionStack.clear();
  53                 throw;
  54         }
  55
  56         return root;
  57 }
  58
  59 void ExpressionGenerator::generate (Expression* root)
  60 {
  61         DE_ASSERT(m_expressionStack.empty());
  62
  63         // Initialize stack
  64         m_expressionStack.push_back(root);
  65         m_state.setExpressionDepth(m_state.getExpressionDepth()+1);
  66
  67         // Process until done
  68         while (!m_expressionStack.empty())
  69         {
  70                 DE_ASSERT(m_state.getExpressionDepth() <= m_state.getShaderParameters().maxExpressionDepth);
  71
  72                 Expression* curExpr = m_expressionStack[m_expressionStack.size()-1];
  73                 Expression*     child   = curExpr->createNextChild(m_state);
  74
  75                 if (child)
  76                 {
  77                         m_expressionStack.push_back(child);
  78                         m_state.setExpressionDepth(m_state.getExpressionDepth()+1);
  79                 }
  80                 else
  81                 {
  82                         m_expressionStack.pop_back();
  83                         m_state.setExpressionDepth(m_state.getExpressionDepth()-1);
  84                 }
  85         }
  86 }
  87
  88 } // rsg