feat: glsl simula text shaders

src/nodes/drawable/mod.rs

@@ -1,5 +1,6 @@
 pub mod lines;
 pub mod model;
+pub mod shaders;
 pub mod text;
 
 use self::{

src/nodes/drawable/shaders.rs

@@ -0,0 +1,54 @@
+use std::{ffi::CString, mem::transmute};
+
+use smithay::backend::renderer::gles::ffi::{Gles2, FRAGMENT_SHADER, VERTEX_SHADER};
+use stereokit::Shader;
+
+struct FfiAssetHeader {
+	asset_type: i32,
+	asset_state: i32,
+	id: u64,
+	index: u64,
+	refs: i32,
+}
+
+struct FfiSkgShader {
+	meta: *mut u8,
+	vertex: u32,
+	pixel: u32,
+	program: u32,
+	compute: u32,
+}
+
+struct FfiShader {
+	header: FfiAssetHeader,
+	shader: FfiSkgShader,
+}
+
+unsafe fn load_shader(c: &Gles2, source: &str, stage: u32) -> u32 {
+	let shader = c.CreateShader(stage);
+	let shader_source = CString::new(source).unwrap();
+	c.ShaderSource(shader, 1, &shader_source.as_ptr(), std::ptr::null());
+	c.CompileShader(shader);
+	shader
+}
+
+unsafe fn link_program(c: &Gles2, vert: u32, frag: u32) -> u32 {
+	let program = c.CreateProgram();
+	c.AttachShader(vert, VERTEX_SHADER);
+	c.AttachShader(frag, FRAGMENT_SHADER);
+	c.LinkProgram(program);
+	program
+}
+
+pub unsafe fn shader_inject(c: &Gles2, sk_shader: &mut Shader, vert_str: &str, frag_str: &str) {
+	let gl_vert = load_shader(c, vert_str, VERTEX_SHADER);
+	let gl_frag = load_shader(c, frag_str, FRAGMENT_SHADER);
+	let gl_prog = link_program(c, gl_vert, gl_frag);
+
+	let shader: *mut FfiShader = transmute(sk_shader.0.as_mut());
+	if let Some(shader) = shader.as_mut() {
+		shader.shader.vertex = gl_vert;
+		shader.shader.pixel = gl_frag;
+		shader.shader.program = gl_prog;
+	}
+}