XCEngine/docs/api/rhi/opengl/opengl-pipeline-state.md

OpenGLPipelineState

OpenGL 管线状态对象实现，封装多种 OpenGL 状态。

头文件

#include <XCEngine/RHI/OpenGL/OpenGLPipelineState.h>

继承关系

RHIPipelineState (interface)
└── OpenGLPipelineState (implementation)

枚举

OpenGLPrimitiveTopology

值	描述
Points	点
Lines	线
LineStrip	线带
Triangles	三角形
TriangleStrip	三角形带

OpenGLBlendOp

值	OpenGL 常量
Add	GL_FUNC_ADD
Subtract	GL_FUNC_SUBTRACT
ReverseSubtract	GL_FUNC_REVERSE_SUBTRACT
Min	GL_MIN
Max	GL_MAX

CullFace / FrontFace / PolygonMode

enum class CullFace { Front, Back, FrontAndBack };
enum class FrontFace { Clockwise, CounterClockwise };
enum class PolygonMode { Point, Line, Fill };

状态结构体

OpenGLDepthStencilState

struct OpenGLDepthStencilState {
    bool depthTestEnable = true;
    bool depthWriteEnable = true;
    ComparisonFunc depthFunc = ComparisonFunc::Less;
    bool stencilEnable = false;
    uint8_t stencilReadMask = 0xFF;
    uint8_t stencilWriteMask = 0xFF;
    int stencilRef = 0;
    ComparisonFunc stencilFunc = ComparisonFunc::Always;
    StencilOp stencilFailOp = StencilOp::Keep;
    StencilOp stencilDepthFailOp = StencilOp::Keep;
    StencilOp stencilDepthPassOp = StencilOp::Keep;
};

OpenGLBlendState

struct OpenGLBlendState {
    bool blendEnable = false;
    BlendFactor srcBlend = BlendFactor::SrcAlpha;
    BlendFactor dstBlend = BlendFactor::InvSrcAlpha;
    BlendFactor srcBlendAlpha = BlendFactor::One;
    BlendFactor dstBlendAlpha = BlendFactor::Zero;
    BlendOp blendOp = BlendOp::Add;
    BlendOp blendOpAlpha = BlendOp::Add;
    uint8_t colorWriteMask = 0xF;
    float blendFactor[4] = { 0.0f, 0.0f, 0.0f, 0.0f };
};

OpenGLRasterizerState

struct OpenGLRasterizerState {
    bool cullFaceEnable = true;
    CullFace cullFace = CullFace::Back;
    FrontFace frontFace = FrontFace::CounterClockwise;
    PolygonMode polygonMode = PolygonMode::Fill;
    float polygonOffsetFactor = 0.0f;
    float polygonOffsetUnits = 0.0f;
    bool depthClipEnable = true;
    bool scissorTestEnable = false;
    bool multisampleEnable = false;
    bool sampleAlphaToCoverageEnable = false;
};

ViewportState / ScissorState / LogicalOperation

struct ViewportState {
    float x = 0.0f, y = 0.0f;
    float width = 0.0f, height = 0.0f;
    float minDepth = 0.0f, maxDepth = 1.0f;
};

struct ScissorState {
    bool enable = false;
    int x = 0, y = 0, width = 0, height = 0;
};

struct LogicalOperation {
    bool enable = false;
    uint32_t operation = 0;
};

公共成员函数

生命周期

OpenGLPipelineState()

~OpenGLPipelineState() override

void Shutdown() override

绑定

void Bind() override

应用所有状态。

void Unbind() override

void* GetNativeHandle() override

PipelineType GetType() const override { return PipelineType::Graphics; }

状态设置

void SetDepthStencilState(const OpenGLDepthStencilState& state)

void SetBlendState(const OpenGLBlendState& state)

void SetRasterizerState(const OpenGLRasterizerState& state)

void SetViewport(const ViewportState& state)

void SetScissor(const ScissorState& state)

void SetLogicalOperation(const LogicalOperation& state)

状态应用

void Apply()

应用所有状态。

void ApplyDepthStencil()

void ApplyBlend()

void ApplyRasterizer()

void ApplyViewport()

void ApplyScissor()

清除

void SetClearColor(float r, float g, float b, float a)

void Clear(unsigned int buffers)

Shader 附加

void AttachShader(unsigned int program)

void DetachShader()

属性获取

const OpenGLDepthStencilState& GetDepthStencilState() const

const OpenGLBlendState& GetBlendState() const

const OpenGLRasterizerState& GetRasterizerState() const

内部成员

成员	类型	描述
m_depthStencilState	OpenGLDepthStencilState	深度模板状态
m_blendState	OpenGLBlendState	混合状态
m_rasterizerState	OpenGLRasterizerState	光栅化状态
m_viewportState	ViewportState	视口状态
m_scissorState	ScissorState	裁剪状态
m_logicalOperation	LogicalOperation	逻辑操作
m_clearColor	float[4]	清除颜色
m_program	unsigned int	GL program
m_programAttached	bool	program 是否附加

使用示例

OpenGLPipelineState pso;

OpenGLDepthStencilState ds;
ds.depthTestEnable = true;
ds.depthWriteEnable = true;
ds.depthFunc = ComparisonFunc::Less;
pso.SetDepthStencilState(ds);

OpenGLBlendState blend;
blend.blendEnable = true;
blend.srcBlend = BlendFactor::SrcAlpha;
blend.dstBlend = BlendFactor::InvSrcAlpha;
pso.SetBlendState(blend);

OpenGLRasterizerState raster;
raster.cullFaceEnable = true;
raster.cullFace = CullFace::Back;
pso.SetRasterizerState(raster);

pso.AttachShader(shaderProgram);
pso.Bind();