Implement clip_rect in WebGL
@@ -4,7 +4,7 @@ use {
web_sys::{WebGlBuffer, WebGlProgram, WebGlRenderingContext, WebGlShader, WebGlTexture},
};
-use emigui::{Color, Mesh, PaintBatches, Rect, Texture};
+use emigui::{Color, Mesh, PaintBatches, Texture};
type Gl = WebGlRenderingContext;
@@ -58,21 +58,26 @@ impl Painter {
&gl,
Gl::VERTEX_SHADER,
r#"
+ uniform vec4 u_clip_rect; // min_x, min_y, max_x, max_y
uniform vec2 u_screen_size;
uniform vec2 u_tex_size;
attribute vec2 a_pos;
attribute vec2 a_tc;
attribute vec4 a_color;
- varying vec2 v_tc;
+ varying vec2 v_pos;
varying vec4 v_color;
+ varying vec2 v_tc;
+ varying vec4 v_clip_rect;
void main() {
gl_Position = vec4(
2.0 * a_pos.x / u_screen_size.x - 1.0,
1.0 - 2.0 * a_pos.y / u_screen_size.y,
0.0,
1.0);
- v_tc = a_tc / u_tex_size;
+ v_pos = a_pos;
v_color = a_color;
+ v_tc = a_tc / u_tex_size;
+ v_clip_rect = u_clip_rect;
}
"#,
)?;
@@ -82,9 +87,15 @@ impl Painter {
r#"
uniform sampler2D u_sampler;
precision highp float;
- varying vec2 v_tc;
+ varying vec2 v_pos;
varying vec4 v_color;
+ varying vec2 v_tc;
+ varying vec4 v_clip_rect;
void main() {
+ if (v_pos.x < v_clip_rect.x) { discard; }
+ if (v_pos.y < v_clip_rect.y) { discard; }
+ if (v_pos.x > v_clip_rect.z) { discard; }
+ if (v_pos.y > v_clip_rect.w) { discard; }
gl_FragColor = v_color;
gl_FragColor.a *= texture2D(u_sampler, v_tc).a;
}
@@ -160,6 +171,10 @@ impl Painter {
gl.active_texture(Gl::TEXTURE0);
gl.bind_texture(Gl::TEXTURE_2D, Some(&self.texture));
+ let u_clip_rect_loc = gl
+ .get_uniform_location(&self.program, "u_clip_rect")
+ .unwrap();
+
let u_screen_size_loc = gl
.get_uniform_location(&self.program, "u_screen_size")
.unwrap();
@@ -196,14 +211,22 @@ impl Painter {
gl.clear(Gl::COLOR_BUFFER_BIT);
for (clip_rect, mesh) in batches {
+ gl.uniform4f(
+ Some(&u_clip_rect_loc),
+ clip_rect.min().x,
+ clip_rect.min().y,
+ clip_rect.max().x,
+ clip_rect.max().y,
+ );
+
for mesh in mesh.split_to_u16() {
- self.paint_mesh(&clip_rect, &mesh)?;
+ self.paint_mesh(&mesh)?;
}
}
Ok(())
}
- fn paint_mesh(&mut self, _clip_rec: &Rect, mesh: &Mesh) -> Result<(), JsValue> {
+ fn paint_mesh(&self, mesh: &Mesh) -> Result<(), JsValue> {
let indices: Vec<u16> = mesh.indices.iter().map(|idx| *idx as u16).collect();
let mut positions: Vec<f32> = Vec::with_capacity(2 * mesh.vertices.len());
