1 //
2 // Copyright 2017 The ANGLE Project Authors. All rights reserved.
3 // Use of this source code is governed by a BSD-style license that can be
4 // found in the LICENSE file.
5 //
6 // ClampPointSize.cpp: Limit the value that is written to gl_PointSize.
7 //
8
9 #include "compiler/translator/tree_ops/ClampPointSize.h"
10
11 #include "compiler/translator/SymbolTable.h"
12 #include "compiler/translator/tree_util/BuiltIn.h"
13 #include "compiler/translator/tree_util/FindSymbolNode.h"
14 #include "compiler/translator/tree_util/IntermNode_util.h"
15 #include "compiler/translator/tree_util/RunAtTheEndOfShader.h"
16
17 namespace sh
18 {
19
ClampPointSize(TCompiler * compiler,TIntermBlock * root,float minPointSize,float maxPointSize,TSymbolTable * symbolTable)20 bool ClampPointSize(TCompiler *compiler,
21 TIntermBlock *root,
22 float minPointSize,
23 float maxPointSize,
24 TSymbolTable *symbolTable)
25 {
26 // Only clamp gl_PointSize if it's used in the shader.
27 const TIntermSymbol *glPointSize = FindSymbolNode(root, ImmutableString("gl_PointSize"));
28 if (glPointSize == nullptr)
29 {
30 return true;
31 }
32
33 TIntermTyped *pointSizeNode = glPointSize->deepCopy();
34
35 TConstantUnion *minPointSizeConstant = new TConstantUnion();
36 TConstantUnion *maxPointSizeConstant = new TConstantUnion();
37 minPointSizeConstant->setFConst(minPointSize);
38 maxPointSizeConstant->setFConst(maxPointSize);
39 TIntermConstantUnion *minPointSizeNode =
40 new TIntermConstantUnion(minPointSizeConstant, TType(EbtFloat, EbpHigh, EvqConst));
41 TIntermConstantUnion *maxPointSizeNode =
42 new TIntermConstantUnion(maxPointSizeConstant, TType(EbtFloat, EbpHigh, EvqConst));
43
44 // clamp(gl_PointSize, minPointSize, maxPointSize)
45 TIntermSequence clampArguments;
46 clampArguments.push_back(pointSizeNode->deepCopy());
47 clampArguments.push_back(minPointSizeNode);
48 clampArguments.push_back(maxPointSizeNode);
49 TIntermTyped *clampedPointSize =
50 CreateBuiltInFunctionCallNode("clamp", &clampArguments, *symbolTable, 100);
51
52 // gl_PointSize = clamp(gl_PointSize, minPointSize, maxPointSize)
53 TIntermBinary *assignPointSize = new TIntermBinary(EOpAssign, pointSizeNode, clampedPointSize);
54
55 return RunAtTheEndOfShader(compiler, root, assignPointSize, symbolTable);
56 }
57
58 } // namespace sh
59