#include <SkMesh.h>

Inheritance diagram for SkMeshSpecification:

Classes
struct	Attribute

struct	Result

struct	Varying

Public Types
using	Uniform = SkRuntimeEffect::Uniform

using	Child = SkRuntimeEffect::Child

Public Member Functions
	~SkMeshSpecification ()

SkSpan< const Attribute >	attributes () const

size_t	uniformSize () const

SkSpan< const Uniform >	uniforms () const

SkSpan< const Child >	children () const

const Child *	findChild (std::string_view name) const

const Uniform *	findUniform (std::string_view name) const

const Attribute *	findAttribute (std::string_view name) const

const Varying *	findVarying (std::string_view name) const

size_t	stride () const

SkColorSpace *	colorSpace () const

Public Member Functions inherited from SkNVRefCnt< SkMeshSpecification >
	SkNVRefCnt ()

	~SkNVRefCnt ()

bool	unique () const

void	ref () const

void	unref () const

void	deref () const

bool	refCntGreaterThan (int32_t threadIsolatedTestCnt) const

Static Public Member Functions
static Result	Make (SkSpan< const Attribute > attributes, size_t vertexStride, SkSpan< const Varying > varyings, const SkString &vs, const SkString &fs)

static Result	Make (SkSpan< const Attribute > attributes, size_t vertexStride, SkSpan< const Varying > varyings, const SkString &vs, const SkString &fs, sk_sp< SkColorSpace > cs)

static Result	Make (SkSpan< const Attribute > attributes, size_t vertexStride, SkSpan< const Varying > varyings, const SkString &vs, const SkString &fs, sk_sp< SkColorSpace > cs, SkAlphaType at)

Static Public Attributes
static constexpr size_t	kMaxStride = 1024

static constexpr size_t	kMaxAttributes = 8

static constexpr size_t	kStrideAlignment = 4

static constexpr size_t	kOffsetAlignment = 4

static constexpr size_t	kMaxVaryings = 6

Friends
struct	SkMeshSpecificationPriv

Detailed Description

A specification for custom meshes. Specifies the vertex buffer attributes and stride, the vertex program that produces a user-defined set of varyings, and a fragment program that ingests the interpolated varyings and produces local coordinates for shading and optionally a color.

The varyings must include a float2 named "position". If the passed varyings does not contain such a varying then one is implicitly added to the final specification and the SkSL Varyings struct described below. It is an error to have a varying named "position" that has a type other than float2.

The provided attributes and varyings are used to create Attributes and Varyings structs in SkSL that are used by the shaders. Each attribute from the Attribute span becomes a member of the SkSL Attributes struct and likewise for the varyings.

The signature of the vertex program must be: Varyings main(const Attributes).

The signature of the fragment program must be either: float2 main(const Varyings) or float2 main(const Varyings, out (half4|float4) color)

where the return value is the local coordinates that will be used to access SkShader. If the color variant is used, the returned color will be blended with SkPaint's SkShader (or SkPaint color in absence of a SkShader) using the SkBlender passed to SkCanvas drawMesh(). To use interpolated local space positions as the shader coordinates, equivalent to how SkPaths are shaded, return the position field from the Varying struct as the coordinates.

The vertex and fragment programs may both contain uniforms. Uniforms with the same name are assumed to be shared between stages. It is an error to specify uniforms in the vertex and fragment program with the same name but different types, dimensionality, or layouts.

Definition at line 65 of file SkMesh.h.

Member Typedef Documentation

◆ Child

using SkMeshSpecification::Child = SkRuntimeEffect::Child

Definition at line 107 of file SkMesh.h.

◆ Uniform

using SkMeshSpecification::Uniform = SkRuntimeEffect::Uniform

Definition at line 106 of file SkMesh.h.

Constructor & Destructor Documentation

◆ ~SkMeshSpecification()

SkMeshSpecification::~SkMeshSpecification ( )

default

Member Function Documentation

◆ attributes()

SkSpan< const Attribute > SkMeshSpecification::attributes ( ) const

inline

Definition at line 157 of file SkMesh.h.

157{ return SkSpan(fAttributes); }

SkSpan

Definition SkSpan_impl.h:65

◆ children()

SkSpan< const Child > SkMeshSpecification::children ( ) const

inline

Provides basic info about individual children: names, indices and runtime effect type.

Definition at line 173 of file SkMesh.h.

173{ return SkSpan(fChildren); }

◆ colorSpace()

SkColorSpace * SkMeshSpecification::colorSpace ( ) const

inline

Definition at line 189 of file SkMesh.h.

189{ return fColorSpace.get(); }

sk_sp::get

T * get() const

Definition SkRefCnt.h:303

◆ findAttribute()

const Attribute * SkMeshSpecification::findAttribute ( std::string_view name ) const

Returns a pointer to the named attribute, or nullptr if not found.

Definition at line 665 of file SkMesh.cpp.

                                                                             {
    for (const Attribute& attr : fAttributes) {
        if (name == attr.name.c_str()) {
            return &attr;
        }
    }
    return nullptr;
}

◆ findChild()

const Child * SkMeshSpecification::findChild ( std::string_view name ) const

Returns a pointer to the named child's description, or nullptr if not found.

Definition at line 656 of file SkMesh.cpp.

                                                                     {
    for (const Child& child : fChildren) {
        if (child.name == name) {
            return &child;
        }
    }
    return nullptr;
}

◆ findUniform()

const Uniform * SkMeshSpecification::findUniform ( std::string_view name ) const

Returns a pointer to the named uniform variable's description, or nullptr if not found.

Definition at line 647 of file SkMesh.cpp.

                                                                         {
    for (const Uniform& uniform : fUniforms) {
        if (uniform.name == name) {
            return &uniform;
        }
    }
    return nullptr;
}

◆ findVarying()

const Varying * SkMeshSpecification::findVarying ( std::string_view name ) const

Returns a pointer to the named varying, or nullptr if not found.

Definition at line 674 of file SkMesh.cpp.

                                                                         {
    for (const Varying& varying : fVaryings) {
        if (name == varying.name.c_str()) {
            return &varying;
        }
    }
    return nullptr;
}

◆ Make() [1/3]

SkMeshSpecification::Result SkMeshSpecification::Make	(	SkSpan< const Attribute >	attributes,
		size_t	vertexStride,
		SkSpan< const Varying >	varyings,
		const SkString &	vs,
		const SkString &	fs
	)

static

If successful the return is a specification and an empty error string. Otherwise, it is a null specification a non-empty error string.

Parameters

attributes	The vertex attributes that will be consumed by 'vs'. Attributes need not be tightly packed but attribute offsets must be aligned to kOffsetAlignment and offset + size may not be greater than 'vertexStride'. At least one attribute is required.
vertexStride	The offset between successive attribute values. This must be aligned to kStrideAlignment.
varyings	The varyings that will be written by 'vs' and read by 'fs'. This may be empty.
vs	The vertex shader code that computes a vertex position and the varyings from the attributes.
fs	The fragment code that computes a local coordinate and optionally a color from the varyings. The local coordinate is used to sample SkShader.
cs	The colorspace of the color produced by 'fs'. Ignored if 'fs's main() function does not have a color out param.
at	The alpha type of the color produced by 'fs'. Ignored if 'fs's main() function does not have a color out param. Cannot be kUnknown.

Definition at line 389 of file SkMesh.cpp.

                                                                          {
    return Make(attributes,
                vertexStride,
                varyings,
                vs,
                fs,
                SkColorSpace::MakeSRGB(),
                kPremul_SkAlphaType);
}

◆ Make() [2/3]

SkMeshSpecification::Result SkMeshSpecification::Make	(	SkSpan< const Attribute >	attributes,
		size_t	vertexStride,
		SkSpan< const Varying >	varyings,
		const SkString &	vs,
		const SkString &	fs,
		sk_sp< SkColorSpace >	cs
	)

static

Definition at line 403 of file SkMesh.cpp.

                                                                              {
    return Make(attributes, vertexStride, varyings, vs, fs, std::move(cs), kPremul_SkAlphaType);
}

◆ Make() [3/3]

SkMeshSpecification::Result SkMeshSpecification::Make	(	SkSpan< const Attribute >	attributes,
		size_t	vertexStride,
		SkSpan< const Varying >	varyings,
		const SkString &	vs,
		const SkString &	fs,
		sk_sp< SkColorSpace >	cs,
		SkAlphaType	at
	)

static

Definition at line 412 of file SkMesh.cpp.

                                                                      {
    SkString attributesStruct("struct Attributes {\n");
    for (const auto& a : attributes) {
        attributesStruct.appendf("  %s %s;\n", attribute_type_string(a.type), a.name.c_str());
    }
    attributesStruct.append("};\n");
 
    bool userProvidedPositionVarying = false;
    for (const auto& v : varyings) {
        if (v.name.equals("position")) {
            if (v.type != Varying::Type::kFloat2) {
                return {nullptr, SkString("Varying \"position\" must have type float2.")};
            }
            userProvidedPositionVarying = true;
        }
    }
 
    STArray<kMaxVaryings, Varying> tempVaryings;
    if (!userProvidedPositionVarying) {
        // Even though we check the # of varyings in MakeFromSourceWithStructs we check here, too,
        // to avoid overflow with + 1.
        if (varyings.size() > kMaxVaryings - 1) {
            RETURN_FAILURE("A maximum of %zu varyings is allowed.", kMaxVaryings);
        }
        for (const auto& v : varyings) {
            tempVaryings.push_back(v);
        }
        tempVaryings.push_back(Varying{Varying::Type::kFloat2, SkString("position")});
        varyings = tempVaryings;
    }
 
    SkString varyingStruct("struct Varyings {\n");
    for (const auto& v : varyings) {
        varyingStruct.appendf("  %s %s;\n", varying_type_string(v.type), v.name.c_str());
    }
    varyingStruct.append("};\n");
 
    SkString fullVS;
    fullVS.append(varyingStruct.c_str());
    fullVS.append(attributesStruct.c_str());
    fullVS.append(vs.c_str());
 
    SkString fullFS;
    fullFS.append(varyingStruct.c_str());
    fullFS.append(fs.c_str());
 
    return MakeFromSourceWithStructs(attributes,
                                     vertexStride,
                                     varyings,
                                     fullVS,
                                     fullFS,
                                     std::move(cs),
                                     at);
}

◆ stride()

size_t SkMeshSpecification::stride ( ) const

inline

Definition at line 187 of file SkMesh.h.

187{ return fStride; }

◆ uniforms()

SkSpan< const Uniform > SkMeshSpecification::uniforms ( ) const

inline

Provides info about individual uniforms including the offset into an SkData where each uniform value should be placed.

Definition at line 170 of file SkMesh.h.

170{ return SkSpan(fUniforms); }

◆ uniformSize()

size_t SkMeshSpecification::uniformSize ( ) const

Combined size of all 'uniform' variables. When creating a SkMesh with this specification provide an SkData of this size, containing values for all of those variables. Use uniforms() to get the offset of each uniform within the SkData.

Definition at line 642 of file SkMesh.cpp.

                                              {
    return fUniforms.empty() ? 0
                             : SkAlign4(fUniforms.back().offset + fUniforms.back().sizeInBytes());
}

Friends And Related Symbol Documentation

◆ SkMeshSpecificationPriv

friend struct SkMeshSpecificationPriv

friend

Definition at line 192 of file SkMesh.h.

Member Data Documentation

◆ kMaxAttributes

constexpr size_t SkMeshSpecification::kMaxAttributes = 8

staticconstexpr

Definition at line 69 of file SkMesh.h.

◆ kMaxStride

constexpr size_t SkMeshSpecification::kMaxStride = 1024

staticconstexpr

These values are enforced when creating a specification.

Definition at line 68 of file SkMesh.h.

◆ kMaxVaryings

constexpr size_t SkMeshSpecification::kMaxVaryings = 6

staticconstexpr

Definition at line 72 of file SkMesh.h.

◆ kOffsetAlignment

constexpr size_t SkMeshSpecification::kOffsetAlignment = 4

staticconstexpr

Definition at line 71 of file SkMesh.h.

◆ kStrideAlignment

constexpr size_t SkMeshSpecification::kStrideAlignment = 4

staticconstexpr

Definition at line 70 of file SkMesh.h.

The documentation for this class was generated from the following files:

third_party/skia/include/core/SkMesh.h
third_party/skia/src/core/SkMesh.cpp

Classes

Public Types

Public Member Functions

Static Public Member Functions

Static Public Attributes

Friends

Detailed Description

Member Typedef Documentation

◆ Child

◆ Uniform

Constructor & Destructor Documentation

◆ ~SkMeshSpecification()

Member Function Documentation

◆ attributes()

◆ children()

◆ colorSpace()

◆ findAttribute()

◆ findChild()

◆ findUniform()

◆ findVarying()

◆ Make() [1/3]

◆ Make() [2/3]

◆ Make() [3/3]

◆ stride()

◆ uniforms()

◆ uniformSize()

Friends And Related Symbol Documentation

◆ SkMeshSpecificationPriv

Member Data Documentation

◆ kMaxAttributes

◆ kMaxStride

◆ kMaxVaryings

◆ kOffsetAlignment

◆ kStrideAlignment