Renderer

Forward renderer for drawing a scene from a given camera.

The Renderer owns GPU state and draw logic for rendering a Scene with a specified Camera. It is typically constructed and driven by the Application runtime, but can also be used directly in manual setups.

Typical usage:

vglx::Renderer renderer({
  .framebuffer_width = window.FramebufferWidth(),
  .framebuffer_height = window.FramebufferHeight(),
  .clear_color = 0x444444
});

auto ok = renderer.Initialize();
if (!ok) {
  HandleError(ok.error());
}

// Per-frame:
renderer.Render(scene.get(), camera.get());

Construction

Constructors

Renderer()

vglx::Renderer::Renderer(const Renderer::Parameters &params)

Parameter	Description
params	Renderer::Parameters

Constructs a renderer object with the given parameters. GPU resources are not created until Initialize is called.

Types

Renderer::Parameters struct

Construction parameters for Renderer.

Name	Type	Description
clear_color	Color	Clear color used at the start of a frame.
framebuffer_height	int	Current framebuffer height in pixels.
framebuffer_width	int	Current framebuffer width in pixels.

Functions

Initialize() std::expected< void, std::string >

std::expected< void, std::string > vglx::Renderer::Initialize()

Initializes GPU state and allocates required resources.

Render() void

void vglx::Renderer::Render(Scene *scene, Camera *camera)

Parameter	Description
scene	Pointer to the scene to render (must be non-null).
camera	Pointer to the active camera (must be non-null).

Renders the given scene from the specified camera. The scene is expected to be in a consistent state for rendering. If you are using the runtime path, this is handled automatically. In direct initialization flows, call your per-frame update routine (e.g., Scene::Advance) prior to rendering.

RenderedObjectsPerFrame() size_t

size_t vglx::Renderer::RenderedObjectsPerFrame() const

Returns the number of renderable objects drawn in the last frame. Intended for statistics overlays and debugging.

SetClearColor() void

void vglx::Renderer::SetClearColor(const Color &color)

Parameter	Description
color	Clear color in RGB format.

Sets the clear color for subsequent frames. The color is applied at the start of each frame when the framebuffer is cleared. Typically used to define the background color of the rendering surface.

SetViewport() void

void vglx::Renderer::SetViewport(int x, int y, int width, int height)

Parameter	Description
x	Left pixel of the viewport.
y	Bottom pixel of the viewport.
width	Viewport width in pixels.
height	Viewport height in pixels.

Sets the active viewport rectangle in pixels. Call this when the framebuffer size changes or when rendering to a sub-rectangle of the target.