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 
ExpressionGenerator(GeneratorState & state)29 ExpressionGenerator::ExpressionGenerator (GeneratorState& state)
30 	: m_state(state)
31 {
32 }
33 
~ExpressionGenerator(void)34 ExpressionGenerator::~ExpressionGenerator (void)
35 {
36 }
37 
generate(const ValueRange & valueRange,int initialDepth)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 
generate(Expression * root)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
89