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Implement clip_rect in WebGL

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This commit is contained in:
Emil Ernerfeldt 2020-04-21 07:51:48 +02:00
parent 864eae2081
commit 9af64a6468
1 changed files with 29 additions and 6 deletions
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35
emigui_wasm/src/webgl.rs
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@ -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());