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path: root/alacritty/src/renderer/text/gles2.rs
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-rw-r--r--alacritty/src/renderer/text/gles2.rs81
1 files changed, 51 insertions, 30 deletions
diff --git a/alacritty/src/renderer/text/gles2.rs b/alacritty/src/renderer/text/gles2.rs
index 4d8347bf..32aaa173 100644
--- a/alacritty/src/renderer/text/gles2.rs
+++ b/alacritty/src/renderer/text/gles2.rs
@@ -11,11 +11,12 @@ use crate::display::SizeInfo;
use crate::gl;
use crate::gl::types::*;
use crate::renderer::shader::{ShaderProgram, ShaderVersion};
-use crate::renderer::{cstr, Error};
+use crate::renderer::{cstr, Error, GlExtensions};
use super::atlas::{Atlas, ATLAS_SIZE};
use super::{
- Glyph, LoadGlyph, LoaderApi, TextRenderApi, TextRenderBatch, TextRenderer, TextShader,
+ glsl3, Glyph, LoadGlyph, LoaderApi, RenderingGlyphFlags, RenderingPass, TextRenderApi,
+ TextRenderBatch, TextRenderer, TextShader,
};
// Shader source.
@@ -32,13 +33,21 @@ pub struct Gles2Renderer {
batch: Batch,
current_atlas: usize,
active_tex: GLuint,
+ dual_source_blending: bool,
}
impl Gles2Renderer {
pub fn new() -> Result<Self, Error> {
info!("Using OpenGL ES 2.0 renderer");
- let program = TextShaderProgram::new(ShaderVersion::Gles2)?;
+ let dual_source_blending = GlExtensions::contains("GL_EXT_blend_func_extended")
+ || GlExtensions::contains("GL_ARB_blend_func_extended");
+
+ if dual_source_blending {
+ info!("Using dual source blending");
+ }
+
+ let program = TextShaderProgram::new(ShaderVersion::Gles2, dual_source_blending)?;
let mut vao: GLuint = 0;
let mut vbo: GLuint = 0;
let mut ebo: GLuint = 0;
@@ -139,6 +148,7 @@ impl Gles2Renderer {
batch: Batch::new(),
current_atlas: 0,
active_tex: 0,
+ dual_source_blending,
})
}
}
@@ -180,6 +190,7 @@ impl<'a> TextRenderer<'a> for Gles2Renderer {
atlas: &mut self.atlas,
current_atlas: &mut self.current_atlas,
program: &mut self.program,
+ dual_source_blending: self.dual_source_blending,
});
unsafe {
@@ -205,7 +216,7 @@ impl<'a> TextRenderer<'a> for Gles2Renderer {
/// Maximum items to be drawn in a batch.
///
/// We use the closest number to `u16::MAX` dividable by 4 (amount of vertices we push for a glyph),
-/// since it's the maximum possible index in `glDrawElements` in gles2.
+/// since it's the maximum possible index in `glDrawElements` in GLES2.
const BATCH_MAX: usize = (u16::MAX - u16::MAX % 4) as usize;
#[derive(Debug)]
@@ -269,7 +280,12 @@ impl TextRenderBatch for Batch {
let glyph_x = cell.point.column.0 as i16 * size_info.cell_width() as i16 + glyph.left;
let glyph_y = (cell.point.line + 1) as i16 * size_info.cell_height() as i16 - glyph.top;
- let colored = if glyph.multicolor { 1 } else { 0 };
+ let colored = if glyph.multicolor {
+ RenderingGlyphFlags::COLORED
+ } else {
+ RenderingGlyphFlags::empty()
+ };
+
let is_wide = if cell.flags.contains(Flags::WIDE_CHAR) { 2 } else { 1 };
let mut vertex = TextVertex {
@@ -322,6 +338,7 @@ pub struct RenderApi<'a> {
atlas: &'a mut Vec<Atlas>,
current_atlas: &'a mut usize,
program: &'a mut TextShaderProgram,
+ dual_source_blending: bool,
}
impl<'a> Drop for RenderApi<'a> {
@@ -375,19 +392,25 @@ impl<'a> TextRenderApi<Batch> for RenderApi<'a> {
gl::BlendFunc(gl::ONE, gl::ZERO);
gl::DrawElements(gl::TRIANGLES, num_indices, gl::UNSIGNED_SHORT, ptr::null());
- // First text rendering pass.
self.program.set_rendering_pass(RenderingPass::SubpixelPass1);
- gl::BlendFuncSeparate(gl::ZERO, gl::ONE_MINUS_SRC_COLOR, gl::ZERO, gl::ONE);
- gl::DrawElements(gl::TRIANGLES, num_indices, gl::UNSIGNED_SHORT, ptr::null());
-
- // Second text rendering pass.
- self.program.set_rendering_pass(RenderingPass::SubpixelPass2);
- gl::BlendFuncSeparate(gl::ONE_MINUS_DST_ALPHA, gl::ONE, gl::ZERO, gl::ONE);
- gl::DrawElements(gl::TRIANGLES, num_indices, gl::UNSIGNED_SHORT, ptr::null());
+ if self.dual_source_blending {
+ // Text rendering pass.
+ gl::BlendFunc(gl::SRC1_COLOR, gl::ONE_MINUS_SRC1_COLOR);
+ } else {
+ // First text rendering pass.
+ gl::BlendFuncSeparate(gl::ZERO, gl::ONE_MINUS_SRC_COLOR, gl::ZERO, gl::ONE);
+ gl::DrawElements(gl::TRIANGLES, num_indices, gl::UNSIGNED_SHORT, ptr::null());
+
+ // Second text rendering pass.
+ self.program.set_rendering_pass(RenderingPass::SubpixelPass2);
+ gl::BlendFuncSeparate(gl::ONE_MINUS_DST_ALPHA, gl::ONE, gl::ZERO, gl::ONE);
+ gl::DrawElements(gl::TRIANGLES, num_indices, gl::UNSIGNED_SHORT, ptr::null());
+
+ // Third text rendering pass.
+ self.program.set_rendering_pass(RenderingPass::SubpixelPass3);
+ gl::BlendFuncSeparate(gl::ONE, gl::ONE, gl::ONE, gl::ONE_MINUS_SRC_ALPHA);
+ }
- // Third pass.
- self.program.set_rendering_pass(RenderingPass::SubpixelPass3);
- gl::BlendFuncSeparate(gl::ONE, gl::ONE, gl::ONE, gl::ONE_MINUS_SRC_ALPHA);
gl::DrawElements(gl::TRIANGLES, num_indices, gl::UNSIGNED_SHORT, ptr::null());
}
@@ -416,7 +439,7 @@ struct TextVertex {
b: u8,
// Whether the glyph is colored.
- colored: u8,
+ colored: RenderingGlyphFlags,
// Background color.
bg_r: u8,
@@ -425,15 +448,6 @@ struct TextVertex {
bg_a: u8,
}
-// NOTE: These flags must be in sync with their usage in the gles2/text.*.glsl shaders.
-#[repr(u8)]
-enum RenderingPass {
- Background = 0,
- SubpixelPass1 = 1,
- SubpixelPass2 = 2,
- SubpixelPass3 = 3,
-}
-
#[derive(Debug)]
pub struct TextShaderProgram {
/// Shader program.
@@ -444,8 +458,11 @@ pub struct TextShaderProgram {
/// Rendering pass.
///
- /// The rendering is split into 4 passes. One is used for the background and the rest to
- /// perform subpixel text rendering according to
+ /// For dual source blending, there are 2 passes; one for background, another for text,
+ /// similar to the GLSL3 renderer.
+ ///
+ /// If GL_EXT_blend_func_extended is not available, the rendering is split into 4 passes.
+ /// One is used for the background and the rest to perform subpixel text rendering according to
/// https://github.com/servo/webrender/blob/master/webrender/doc/text-rendering.md.
///
/// Rendering is split into three passes.
@@ -453,8 +470,12 @@ pub struct TextShaderProgram {
}
impl TextShaderProgram {
- pub fn new(shader_version: ShaderVersion) -> Result<Self, Error> {
- let program = ShaderProgram::new(shader_version, TEXT_SHADER_V, TEXT_SHADER_F)?;
+ pub fn new(shader_version: ShaderVersion, dual_source_blending: bool) -> Result<Self, Error> {
+ let fragment_shader =
+ if dual_source_blending { &glsl3::TEXT_SHADER_F } else { &TEXT_SHADER_F };
+
+ let program = ShaderProgram::new(shader_version, TEXT_SHADER_V, fragment_shader)?;
+
Ok(Self {
u_projection: program.get_uniform_location(cstr!("projection"))?,
u_rendering_pass: program.get_uniform_location(cstr!("renderingPass"))?,
generated by cgit (git 2.34.1) at 2025-07-16 18:25:45 +0000