Draw

Instance Members #

The graphics batcher instance for batched rendering operations. Stored in a static field for performance, since there's only one Draw instance.

Renders an array of visual objects.

Swaps the front and back buffers (unused in Clay backend). Buffer swapping is handled automatically by Clay framework.

Initializes the vertex and index buffers for rendering.

This method sets up the buffer management system and prepares the first set of buffers for use. Should be called before any rendering operations begin.

Begins a rendering pass by enabling vertex attributes.

Enables the core vertex attributes used by all shaders:

• Position (x, y, z)
• Texture coordinates (u, v)
• Color (r, g, b, a)

Additional attributes are enabled dynamically based on the active shader.

Ends the current rendering frame.

Performs any cleanup or finalization needed after all draw operations.

Clears the current render target to transparent white.

This method clears the color buffer with a transparent white background. When rendering to a texture, this marks the render target as updated.

Clears the current render target and applies the application background color.

This method clears the color buffer with the application's configured background color (fully opaque). Used for the main screen clearing.

Enables alpha blending for transparent rendering.

This activates the GPU's blending functionality, allowing pixels to be combined based on their alpha values. Must be enabled for transparency to work correctly.

Disables alpha blending.

When disabled, pixels are rendered opaque regardless of alpha values. This can improve performance when rendering fully opaque content.

Sets the active texture unit slot for multi-texturing.

Modern GPUs support multiple texture units, allowing shaders to sample from multiple textures simultaneously. This method selects which texture unit subsequent texture operations will affect.

Sets the primitive type for rendering.

Determines how vertices are interpreted:

• TRIANGLE: Every 3 vertices form a triangle (default)
• LINE: Every 2 vertices form a line

Gets the currently active texture unit slot.

Sets the active render target for subsequent drawing operations.

This method switches between rendering to a texture (off-screen) or to the main screen buffer. When switching targets, it handles:

• MSAA buffer blitting for antialiased render targets
• Projection and view matrix updates
• Viewport configuration
• Optional automatic clearing

When renderTarget is null, rendering switches back to the main screen.

Activates a shader program for rendering.

This method:

• Sets the shader as the active GPU program
• Uploads projection and modelview matrices as uniforms
• Configures vertex layout based on shader attributes
• Determines if multi-texture batching is supported
• Calculates maximum vertices per batch based on attribute size

The vertex size calculation includes:

• 3 floats for position (x, y, z)
• Custom float attributes defined by the shader
• 1 float for texture slot (if multi-texturing is enabled)

Sets separate blend functions for RGB and alpha channels.

This allows fine control over how colors are blended, with different blend modes for color (RGB) and transparency (alpha) channels.

Called before drawing a quad (currently unused).

Reserved for future optimizations or quad-specific setup.

Called after drawing a quad (currently unused).

Reserved for future optimizations or quad-specific cleanup.

Called before drawing a mesh (currently unused).

Called after drawing a mesh (currently unused).

Enables scissor testing to clip rendering to a rectangular area.

Scissor testing restricts rendering to pixels within the specified rectangle. Any pixels outside this area are discarded by the GPU.

The coordinates are transformed by the current modelview matrix and adjusted for screen density.

Disables scissor testing.

After calling this, rendering is no longer clipped to a rectangular area.

Enables stencil testing for masked rendering.

This configures the stencil test to only render pixels where the stencil buffer equals 1. Used after drawing to the stencil buffer to render content only within the stenciled area.

Disables stencil testing for normal rendering.

Resets stencil configuration to default values where all pixels pass the stencil test and the stencil buffer can be written to.

Begins drawing to the stencil buffer for masking operations.

This sets up the GPU to write to the stencil buffer instead of the color buffer. Pixels drawn will mark areas in the stencil buffer with a value of 1, creating a mask for subsequent rendering.

Ends drawing to the stencil buffer.

Returns to normal color buffer rendering.

Binds a texture to the current texture unit.

Makes the texture available for sampling in shaders. The texture will be bound to the currently active texture unit.

Binds no texture (or a default white texture depending on the graphics backend).

Used when rendering untextured geometry or solid colors.

Checks if a backend texture matches a texture ID.

Gets the texture ID from a backend texture.

Gets the width of a backend texture.

Gets the height of a backend texture.

Gets the actual width of a backend texture (may differ from logical width).

Gets the actual height of a backend texture (may differ from logical height).

Gets the number of vertices currently in the buffer.

Adds a vertex position to the current batch.

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

Begins adding float attributes for a vertex.

Adds a custom float attribute value for the current vertex.

Ends adding float attributes for the current vertex.

Adds an index to the index buffer.

Adds texture coordinates for the current vertex.

Adds a vertex color to the current batch.

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

Checks if the current batch should be flushed before adding more vertices.

Returns true if adding the specified number of vertices or indices would exceed buffer capacity, indicating that the current batch should be sent to the GPU before continuing.

Gets the remaining vertex capacity in the buffer.

Gets the remaining index capacity in the buffer.

Flushes the current batch of vertices to the GPU.

This is the core rendering method that submits all accumulated geometry to the GPU for rendering.

Creates a new Draw backend instance. Initializes the Ceramic renderer for handling visual rendering.

Private Members #

The Ceramic renderer instance used for high-level rendering operations.

Begins a rendering frame (currently unused). Reserved for future use or platform-specific initialization.

Ends a rendering frame (currently unused). Reserved for future use or platform-specific cleanup.

Updates the projection matrix for orthographic rendering.

Creates an orthographic projection matrix that maps logical coordinates to normalized device coordinates (-1 to 1).

The projection uses:

• Origin at top-left (0,0)
• X increases rightward
• Y increases downward
• Z range from -1000 to 1000 for layering

Updates the view matrix for camera transformations.

The view matrix handles:

• Camera position and rotation (via transform parameter)
• Screen density scaling for high-DPI displays
• Y-axis flipping for render-to-texture (textures have inverted Y)

The matrix is inverted at the end (if needed) because the view matrix represents the inverse of the camera transform.

Sets a matrix to identity.

Sets a matrix from a 2D transform.

Metadata #