GraphicsBatcher

clay.spec.GraphicsBatcher (Interface) → clay.opengl.GLGraphicsBatcher

Interface for graphics batcher implementations.

Provides a unified API for batched rendering across different graphics backends (OpenGL, D3D12, etc.). Each backend would implement this interface with platform-specific optimizations.

The graphics batcher manages vertex/index data accumulation and submission to the GPU. It handles buffer cycling to prevent GPU stalls and supports multi-texture batching.

Typical usage flow:

initBuffers() - Initialize at startup
beginRender() - Start frame
Configure state (shader, textures, blend mode)
Submit vertices via putVertex(), putUVs(), putColor(), putIndex()
flush() when buffers full or state changes
endRender() - End frame

Instance Members

initBuffers(): Void

Initializes vertex and index buffers. Called once during startup to allocate GPU resources.

beginRender(): Void

Begins a new rendering frame. Enables vertex attributes and prepares for draw operations.

endRender(): Void

Ends the current rendering frame. Performs any cleanup or finalization needed after all draw operations.

setVertexLayout(hasTextureSlot: Bool, customFloatAttributesSize: Int): Void

Configures the vertex layout for the current shader.

This determines how vertex data is structured in the buffer, including support for multi-texture batching and custom attributes.

Name	Type	Description
`hasTextureSlot`	Bool	Whether vertices include a texture slot for multi-texture batching
`customFloatAttributesSize`	Int	Number of custom float attributes per vertex

setCustomAttributes(attributes: Array<Dynamic>): Void

Sets the custom shader attributes for vertex layout.

These attributes define how custom per-vertex data is structured in the position buffer. Used by shaders that require additional vertex data beyond position, UV, and color.

Name	Type	Description
`attributes`	Array<Dynamic>	Array of shader attributes (objects with 'size' field), or null for none

putVertex(x: Float, y: Float, z: Float): Void

Adds a vertex position to the buffer.

Name	Type	Description
`x`	Float	X coordinate in screen space
`y`	Float	Y coordinate in screen space
`z`	Float	Z coordinate for depth ordering

putVertexWithTextureSlot(x: Float, y: Float, z: Float, textureSlot: Float): Void

Adds a vertex position with texture slot for multi-texture batching.

Name	Type	Description
`x`	Float	X coordinate in screen space
`y`	Float	Y coordinate in screen space
`z`	Float	Z coordinate for depth ordering
`textureSlot`	Float	Texture slot index for multi-texture batching

putUVs(u: Float, v: Float): Void

Adds texture coordinates for the current vertex.

Name	Type	Description
`u`	Float	Horizontal texture coordinate (0.0 to 1.0)
`v`	Float	Vertical texture coordinate (0.0 to 1.0)

putColor(r: Float, g: Float, b: Float, a: Float): Void

Adds color data for the current vertex.

Name	Type	Description
`r`	Float	Red component (0.0 to 1.0)
`g`	Float	Green component (0.0 to 1.0)
`b`	Float	Blue component (0.0 to 1.0)
`a`	Float	Alpha component (0.0 to 1.0)

putIndex(i: Int): Void

Adds an index to the index buffer. Indices reference vertices in the vertex buffer to form primitives.

Name	Type	Description
`i`	Int	Vertex index

putFloatAttribute(index: Int, value: Float): Void

Adds a custom float attribute value for the current vertex. Used with custom shaders that require additional per-vertex data.

Name	Type	Description
`index`	Int	Attribute index (as defined by the shader)
`value`	Float	Attribute value

endFloatAttributes(): Void

Signals the end of custom float attributes for the current vertex. Must be called after all putFloatAttribute() calls for a vertex.

getNumVertices(): Int

Gets the number of vertices currently in the buffer.

Returns	Description
Int	Current vertex count

shouldFlush(numVerticesAfter: Int, numIndicesAfter: Int): Bool

Checks if the buffer should be flushed before adding more geometry.

Name	Type	Description
`numVerticesAfter`	Int	Number of vertices to be added
`numIndicesAfter`	Int	Number of indices to be added

Returns	Description
Bool	True if flush is needed before adding the geometry

remainingVertices(): Int

Gets the remaining vertex capacity in the buffer.

Returns	Description
Int	Number of vertices that can still be added

remainingIndices(): Int

Gets the remaining index capacity in the buffer.

Returns	Description
Int	Number of indices that can still be added

hasAnythingToFlush(): Bool

Checks if there is any geometry in the buffer to flush.

Returns	Description
Bool	True if there are vertices/indices waiting to be submitted

flush(): Void

Flushes all buffered geometry to the GPU.

Submits accumulated vertex and index data as a draw call. Should be called when:

Buffers are full
Render state changes (texture, shader, blend mode)
Frame is complete

clear(r: Float, g: Float, b: Float, a: Float, clearDepth: Bool): Void

Clears the current render target.

Name	Type	Description
`r`	Float	Red component of clear color (0.0 to 1.0)
`g`	Float	Green component of clear color (0.0 to 1.0)
`b`	Float	Blue component of clear color (0.0 to 1.0)
`a`	Float	Alpha component of clear color (0.0 to 1.0)
`clearDepth`	Bool	Whether to also clear the depth buffer

setViewport(x: Int, y: Int, width: Int, height: Int): Void

Sets the viewport dimensions.

Name	Type	Description
`x`	Int	Left edge of viewport
`y`	Int	Bottom edge of viewport
`width`	Int	Viewport width in pixels
`height`	Int	Viewport height in pixels

setPrimitiveType(primitiveType: Int): Void

Sets the primitive type for rendering.

Name	Type	Description
`primitiveType`	Int	0 for triangles, 1 for lines

enableBlending(): Void

Enables alpha blending for subsequent draw operations.

disableBlending(): Void

Disables alpha blending for subsequent draw operations.

setBlendFuncSeparate(srcRgb: Int, dstRgb: Int, srcAlpha: Int, dstAlpha: Int): Void

Sets separate blend functions for RGB and alpha channels.

Name	Type	Description
`srcRgb`	Int	Source blend factor for RGB channels
`dstRgb`	Int	Destination blend factor for RGB channels
`srcAlpha`	Int	Source blend factor for alpha channel
`dstAlpha`	Int	Destination blend factor for alpha channel

setActiveTexture(slot: Int): Void

Sets the active texture slot for multi-texturing.

Name	Type	Description
`slot`	Int	Texture slot index (0-based)

bindTexture(textureId: clay.TextureId): Void

Binds a texture to the current texture slot.

Name	Type	Description
`textureId`	clay.TextureId	Texture identifier to bind

bindNoTexture(): Void

Unbinds any texture from the current texture slot. On some platforms, binds a default white texture instead.

shouldFlipRenderTargetY(): Bool

Returns true if render target MVP matrix should be flipped vertically.

Returns
Bool

setRenderTarget(renderTarget: clay.RenderTarget): Void

Sets the render target for subsequent draw operations.

Name	Type	Description
`renderTarget`	clay.RenderTarget	Render target to draw into, or null for main framebuffer

blitRenderTargetBuffers(renderTarget: clay.RenderTarget, width: Int, height: Int): Void

Resolves MSAA render target buffers. Called when switching away from an antialiased render target.

Name	Type	Description
`renderTarget`	clay.RenderTarget	The render target to resolve
`width`	Int	Width of the render target
`height`	Int	Height of the render target

useShader(shader: clay.GpuShader): Void

Activates a shader program for subsequent draw operations.

Name	Type	Description
`shader`	clay.GpuShader	Shader program to use

setProjectionMatrix(matrix: clay.buffers.Float32Array): Void

Sets the projection matrix uniform.

Name	Type	Description
`matrix`	clay.buffers.Float32Array	4x4 projection matrix as Float32Array (16 elements)

setModelViewMatrix(matrix: clay.buffers.Float32Array): Void

Sets the model-view matrix uniform.

Name	Type	Description
`matrix`	clay.buffers.Float32Array	4x4 model-view matrix as Float32Array (16 elements)

beginStencilWrite(): Void

Begins writing to the stencil buffer. Subsequent draw calls will write to stencil instead of color buffer.

endStencilWrite(): Void

Ends writing to the stencil buffer. Returns to normal color buffer rendering.

enableStencilTest(): Void

Enables stencil testing for subsequent draw operations. Only pixels passing the stencil test will be rendered.

disableStencilTest(): Void

Disables stencil testing for subsequent draw operations.

enableScissor(x: Float, y: Float, width: Float, height: Float): Void

Enables scissor testing with the specified rectangle. Only pixels within this rectangle will be rendered.

Name	Type	Description
`x`	Float	Left edge of scissor rectangle
`y`	Float	Top edge of scissor rectangle
`width`	Float	Width of scissor rectangle
`height`	Float	Height of scissor rectangle

disableScissor(): Void

Disables scissor testing.

GraphicsBatcher

Instance Members #

Instance Members