XCEngine/docs/api/rhi/opengl/opengl-render-target-view.md

OpenGLRenderTargetView

OpenGL 渲染目标视图实现，使用 framebuffer object (FBO)。

头文件

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

枚举

RenderTargetType

值	描述
Texture2D	2D 纹理
Texture2DArray	2D 纹理数组
Texture3D	3D 纹理
TextureCube	立方体贴图
TextureCubeArray	立方体贴图数组

OpenGLRenderTargetViewDesc

struct OpenGLRenderTargetViewDesc {
    RenderTargetType type = RenderTargetType::Texture2D;
    int mipLevel = 0;
    int baseArraySlice = 0;
    int arraySize = 1;
    int layer = 0;
    uint32_t format = 0;
};

公共成员函数

OpenGLRenderTargetView()

~OpenGLRenderTargetView()

bool Initialize(unsigned int texture, const OpenGLRenderTargetViewDesc& desc)

bool Initialize(unsigned int texture, int mipLevel = 0)

bool InitializeCubemap(unsigned int cubemap, int face, int mipLevel = 0)

void Shutdown()

void Bind(unsigned int slot = 0)

void Bind(unsigned int count, const unsigned int* framebuffers, const int* drawBuffers)

void Unbind()

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

void Clear(float r, float g, float b, float a, float depth, uint8_t stencil)

unsigned int GetFramebuffer() const

unsigned int GetTexture() const

int GetMipLevel() const

int GetWidth() const

int GetHeight() const

static void BindFramebuffer(unsigned int framebuffer)

static void UnbindFramebuffer()

内部成员

成员	类型	描述
m_texture	unsigned int	GL texture ID
m_framebuffer	unsigned int	GL framebuffer ID
m_mipLevel	int	Mip 级别
m_width/height	int	尺寸
m_type	RenderTargetType	类型
m_framebuffers	vector<unsigned int>	额外 framebuffer 列表

使用示例

// Create framebuffer with color attachment
OpenGLRenderTargetView rtv;
rtv.Initialize(texture.GetID());

rtv.Bind();
glClear(GL_COLOR_BUFFER_BIT);
glDrawArrays(GL_TRIANGLES, 0, 3);
rtv.Unbind();

// MRT
OpenGLRenderTargetView rtvs[2];
rtvs[0].Initialize(texture0.GetID());
rtvs[1].Initialize(texture1.GetID());

unsigned int fbs[] = { rtvs[0].GetFramebuffer(), rtvs[1].GetFramebuffer() };
int draws[] = { 0, 1 };
rtvs[0].Bind(2, fbs, draws);
glClear(GL_COLOR_BUFFER_BIT);