Trait GpuGeometryBufferTrait

Source

pub trait GpuGeometryBufferTrait: GpuGeometryBufferAsAny {
    // Required methods
    fn set_buffer_data(&self, buffer: usize, data: &[u8]);
    fn element_count(&self) -> usize;
    fn set_triangles(&self, triangles: &[TriangleDefinition]);
    fn set_lines(&self, lines: &[[u32; 2]]);
    fn set_points(&self, points: &[u32]);
}

Expand description

Geometry buffer is a mesh buffer, that could contain multiple vertex buffers and only one element buffer. Element could be either a line or triangle (the most commonly used one).

§Examples

The simplest possible example shows how to create a geometry buffer that has a single triangle:

use fyrox_graphics::{
    buffer::BufferUsage,
    core::{algebra::Vector3, math::TriangleDefinition},
    error::FrameworkError,
    geometry_buffer::{
        AttributeDefinition, AttributeKind, ElementsDescriptor, GpuGeometryBuffer,
        GpuGeometryBufferDescriptor, VertexBufferData, VertexBufferDescriptor,
    },
    server::GraphicsServer,
};
use bytemuck::{Pod, Zeroable};

// Vertex type must implement a bunch of traits, that guarantees that the data will be tightly
// packed with expected order of elements.
#[derive(Pod, Copy, Clone, Zeroable)]
#[repr(C)]
struct Vertex {
    position: Vector3<f32>,
}

fn create_geometry_buffer(
    server: &dyn GraphicsServer,
) -> Result<GpuGeometryBuffer, FrameworkError> {
    let vertices = [
        Vertex {
            position: Vector3::new(0.0, 0.0, 0.0),
        },
        Vertex {
            position: Vector3::new(0.0, 1.0, 0.0),
        },
        Vertex {
            position: Vector3::new(1.0, 0.0, 0.0),
        },
    ];

    let triangles = [TriangleDefinition([0, 1, 2])];

    server.create_geometry_buffer(GpuGeometryBufferDescriptor {
        name: "MyBuffer",
        buffers: &[VertexBufferDescriptor {
            usage: BufferUsage::StaticDraw,
            attributes: &[AttributeDefinition {
                location: 0,
                kind: AttributeKind::Float,
                component_count: 3,
                normalized: false,
                divisor: 0,
            }],
            data: VertexBufferData::new(Some(&vertices)),
        }],
        usage: BufferUsage::StaticDraw,
        elements: ElementsDescriptor::Triangles(&triangles),
    })
}