chromium/third_party/dawn/src/tint/lang/glsl/writer/ast_raise/texture_builtins_from_uniform.h

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#ifndef SRC_TINT_LANG_GLSL_WRITER_AST_RAISE_TEXTURE_BUILTINS_FROM_UNIFORM_H_
#define SRC_TINT_LANG_GLSL_WRITER_AST_RAISE_TEXTURE_BUILTINS_FROM_UNIFORM_H_

#include <vector>

#include "src/tint/api/common/binding_point.h"
#include "src/tint/lang/wgsl/ast/transform/transform.h"

// Forward declarations
namespace tint {
class CloneContext;
}  // namespace tint

namespace tint::glsl::writer {

/// TextureBuiltinsFromUniform is a transform that implements calls to textureNumLevels() and
/// textureNumSamples() by retrieving the texture information from a uniform buffer, as those
/// builtin functions are not available in some version of GLSL.
///
/// The generated uniform buffer will have the form:
///
/// ```
/// struct internal_uniform {
///  texture_builtin_value_0 : u32,
/// };
///
/// @group(0) @binding(0) var tex : texture_2d<f32>;
/// ```
///
/// The binding group and number used for this uniform buffer are provided via
/// the `Config` transform input.
///
/// The transform coverts the texture builtins calls into values lookup from the internal buffer. If
/// the texture is a function parameter instead of a global variable, this transform also takes care
/// of adding extra parameters and arguments to these functions and their call-sites.
///
/// This transform must run before `CombineSamplers` transform so that the binding point of the
/// original texture object can be preserved.
///
class TextureBuiltinsFromUniform final
    : public Castable<TextureBuiltinsFromUniform, ast::transform::Transform> { … };

}  // namespace tint::glsl::writer

#endif  // SRC_TINT_LANG_GLSL_WRITER_AST_RAISE_TEXTURE_BUILTINS_FROM_UNIFORM_H_