blob: cb3ce8533a682fa0d7c953071c0cccfca29f1047 [file] [log] [blame]
// Copyright 2022 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#ifndef SRC_TINT_LANG_SPIRV_WRITER_AST_RAISE_CLAMP_FRAG_DEPTH_H_
#define SRC_TINT_LANG_SPIRV_WRITER_AST_RAISE_CLAMP_FRAG_DEPTH_H_
#include "src/tint/lang/wgsl/ast/transform/transform.h"
namespace tint::spirv::writer {
/// Add clamping of the `@builtin(frag_depth)` output of fragment shaders using two push constants
/// provided by the outside environment. For example the following code:
///
/// ```
/// @fragment fn main() -> @builtin(frag_depth) f32 {
/// return 0.0;
/// }
/// ```
///
/// Is transformed to:
///
/// ```
/// enable chromium_experimental_push_constant;
///
/// struct FragDepthClampArgs {
/// min : f32,
/// max : f32,
/// }
///
/// var<push_constant> frag_depth_clamp_args : FragDepthClampArgs;
///
/// fn clamp_frag_depth(v : f32) -> f32 {
/// return clamp(v, frag_depth_clamp_args.min, frag_depth_clamp_args.max);
/// }
///
/// @fragment
/// fn main() -> @builtin(frag_depth) f32 {
/// return clamp_frag_depth(0.0);
/// }
/// ```
class ClampFragDepth final : public Castable<ClampFragDepth, ast::transform::Transform> {
public:
/// Constructor
ClampFragDepth();
/// Destructor
~ClampFragDepth() override;
/// @copydoc ast::transform::Transform::Apply
ApplyResult Apply(const Program* program,
const ast::transform::DataMap& inputs,
ast::transform::DataMap& outputs) const override;
private:
struct State;
};
} // namespace tint::spirv::writer
#endif // SRC_TINT_LANG_SPIRV_WRITER_AST_RAISE_CLAMP_FRAG_DEPTH_H_