| Flutter Impeller |

texture_descriptor.h
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1 // Copyright 2013 The Flutter Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #ifndef FLUTTER_IMPELLER_CORE_TEXTURE_DESCRIPTOR_H_
6 #define FLUTTER_IMPELLER_CORE_TEXTURE_DESCRIPTOR_H_
7
8 #include "impeller/core/formats.h"
9 #include "impeller/geometry/size.h"
10
11 namespace impeller {
12
13 //------------------------------------------------------------------------------
14 /// @brief Additional compression to apply to a texture. This value is
15 /// ignored on platforms which do not support it.
16 ///
17 /// Lossy compression is only supported on iOS 15+ on A15 chips.
18 enum class CompressionType {
19 kLossless,
20 kLossy,
21 };
22
23 constexpr const char* CompressionTypeToString(CompressionType type) {
24 switch (type) {
25 case CompressionType::kLossless:
26 return "Lossless";
27 case CompressionType::kLossy:
28 return "Lossy";
29 }
30 FML_UNREACHABLE();
31 }
32
33 //------------------------------------------------------------------------------
34 /// @brief A lightweight object that describes the attributes of a texture
35 /// that can then used an allocator to create that texture.
36 ///
37 struct TextureDescriptor {
38 StorageMode storage_mode = StorageMode::kDeviceTransient;
39 TextureType type = TextureType::kTexture2D;
40 PixelFormat format = PixelFormat::kUnknown;
41 ISize size;
42 size_t mip_count = 1u; // Size::MipCount is usually appropriate.
43 TextureUsageMask usage =
44 static_cast<TextureUsageMask>(TextureUsage::kShaderRead);
45 SampleCount sample_count = SampleCount::kCount1;
46 CompressionType compression_type = CompressionType::kLossless;
47
48 constexpr size_t GetByteSizeOfBaseMipLevel() const {
49 if (!IsValid()) {
50 return 0u;
51 }
52 return size.Area() * BytesPerPixelForPixelFormat(format);
53 }
54
55 constexpr size_t GetBytesPerRow() const {
56 if (!IsValid()) {
57 return 0u;
58 }
59 return size.width * BytesPerPixelForPixelFormat(format);
60 }
61
62 constexpr bool SamplingOptionsAreValid() const {
63 const auto count = static_cast<uint64_t>(sample_count);
64 return IsMultisampleCapable(type) ? count > 1 : count == 1;
65 }
66
67 constexpr bool operator==(const TextureDescriptor& other) const {
68 return size == other.size && //
69 storage_mode == other.storage_mode && //
70 format == other.format && //
71 usage == other.usage && //
72 sample_count == other.sample_count && //
73 type == other.type && //
74 compression_type == other.compression_type && //
75 mip_count == other.mip_count;
76 }
77
78 constexpr bool operator!=(const TextureDescriptor& other) const {
79 return !(*this == other);
80 }
81
82 constexpr bool IsValid() const {
83 return format != PixelFormat::kUnknown && //
84 !size.IsEmpty() && //
85 mip_count >= 1u && //
86 SamplingOptionsAreValid();
87 }
88 };
89
90 std::string TextureDescriptorToString(const TextureDescriptor& desc);
91
92 } // namespace impeller
93
94 #endif // FLUTTER_IMPELLER_CORE_TEXTURE_DESCRIPTOR_H_
impeller::TextureUsageMask
uint64_t TextureUsageMask
Definition: formats.h:295
impeller::TextureDescriptor::format
PixelFormat format
Definition: texture_descriptor.h:40
impeller::TextureType
TextureType
Definition: formats.h:257
formats.h
impeller::TextureDescriptor::mip_count
size_t mip_count
Definition: texture_descriptor.h:42
impeller::TextureDescriptorToString
std::string TextureDescriptorToString(const TextureDescriptor &desc)
Definition: texture_descriptor.cc:11
impeller::TextureDescriptor::sample_count
SampleCount sample_count
Definition: texture_descriptor.h:45
impeller::TextureDescriptor::usage
TextureUsageMask usage
Definition: texture_descriptor.h:43
impeller::TextureDescriptor::operator!=
constexpr bool operator!=(const TextureDescriptor &other) const
Definition: texture_descriptor.h:78
impeller::PixelFormat
PixelFormat
The Pixel formats supported by Impeller. The naming convention denotes the usage of the component,...
Definition: formats.h:94
impeller::TextureDescriptor::type
TextureType type
Definition: texture_descriptor.h:39
impeller::TextureDescriptor::IsValid
constexpr bool IsValid() const
Definition: texture_descriptor.h:82
impeller::TSize< int64_t >
impeller::StorageMode::kDeviceTransient
@ kDeviceTransient
impeller::StorageMode
StorageMode
Specified where the allocation resides and how it is used.
Definition: formats.h:27
impeller::BytesPerPixelForPixelFormat
constexpr size_t BytesPerPixelForPixelFormat(PixelFormat format)
Definition: formats.h:442
impeller::CompressionType
CompressionType
Additional compression to apply to a texture. This value is ignored on platforms which do not support...
Definition: texture_descriptor.h:18
impeller::CompressionType::kLossless
@ kLossless
impeller::TextureDescriptor::operator==
constexpr bool operator==(const TextureDescriptor &other) const
Definition: texture_descriptor.h:67
impeller::TextureUsage::kShaderRead
@ kShaderRead
impeller::CompressionTypeToString
constexpr const char * CompressionTypeToString(CompressionType type)
Definition: texture_descriptor.h:23
impeller::CompressionType::kLossy
@ kLossy
impeller::IsMultisampleCapable
constexpr bool IsMultisampleCapable(TextureType type)
Definition: formats.h:278
impeller::TextureType::kTexture2D
@ kTexture2D
impeller::TSize::width
Type width
Definition: size.h:22
impeller::PixelFormat::kUnknown
@ kUnknown
impeller::TextureDescriptor::size
ISize size
Definition: texture_descriptor.h:41
impeller::TSize::Area
constexpr Type Area() const
Definition: size.h:102
impeller::TextureDescriptor::GetByteSizeOfBaseMipLevel
constexpr size_t GetByteSizeOfBaseMipLevel() const
Definition: texture_descriptor.h:48
impeller::TextureDescriptor::SamplingOptionsAreValid
constexpr bool SamplingOptionsAreValid() const
Definition: texture_descriptor.h:62
impeller::SampleCount
SampleCount
Definition: formats.h:290
impeller::SampleCount::kCount1
@ kCount1
impeller::TextureDescriptor::storage_mode
StorageMode storage_mode
Definition: texture_descriptor.h:38
impeller::TextureDescriptor
A lightweight object that describes the attributes of a texture that can then used an allocator to cr...
Definition: texture_descriptor.h:37
impeller::TSize::IsEmpty
constexpr bool IsEmpty() const
Returns true if either of the width or height are 0, negative, or NaN.
Definition: size.h:105
impeller::TextureDescriptor::compression_type
CompressionType compression_type
Definition: texture_descriptor.h:46
impeller
Definition: aiks_context.cc:10
size.h
impeller::TextureDescriptor::GetBytesPerRow
constexpr size_t GetBytesPerRow() const
Definition: texture_descriptor.h:55