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Migrate the glyph buffers to be OpenGL buffers

This commit is contained in:
Patrick Walton 2017-01-23 22:03:40 -08:00
parent 0569831969
commit 1cd3a1e6bd
4 changed files with 135 additions and 40 deletions
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35
resources/shaders/draw.vs.glsl
View File

@ -10,24 +10,40 @@
#version 410
// FIXME(pcwalton): This should be higher. Dynamically query its maximum possible size, perhaps?
#define MAX_GLYPHS 256
// Information about the metrics of each glyph.
layout(std140) struct GlyphDescriptor {
// The left/top/right/bottom offsets of the glyph from point (0, 0) in glyph space.
ivec4 extents;
// The number of units per em in this glyph.
uint unitsPerEm;
// The number of points in this glyph.
uint pointCount;
// The index of the first point.
uint startPoint;
};
// Information about the position of each glyph in the atlas.
layout(std140) struct ImageInfo {
// The left/top/right/bottom positions of the glyph in the atlas.
uvec4 atlasRect;
// The left/top/right/bottom offsets of the glyph from point (0, 0) in glyph space.
ivec4 extents;
// The font size in pixels.
float pointSize;
// The index of the glyph.
uint glyphIndex;
};
// The size of the atlas in pixels.
uniform uvec2 uAtlasSize;
// The number of ems per unit (reciprocal of units per em).
uniform float uEmsPerUnit;
layout(std140) uniform ubGlyphDescriptors {
GlyphDescriptor uGlyphs[MAX_GLYPHS];
};
layout(std140) uniform ubImageInfo {
ImageInfo uImageInfo[256];
ImageInfo uImageInfo[MAX_GLYPHS];
};
// The position of each vertex in glyph space.
@ -45,8 +61,13 @@ void main() {
vVertexID = gl_VertexID;
ImageInfo imageInfo = uImageInfo[aImageIndex];
vec2 glyphPos = vec2(aPosition.x - imageInfo.extents.x, imageInfo.extents.w - aPosition.y);
vec2 atlasPos = glyphPos * uEmsPerUnit * imageInfo.pointSize + vec2(imageInfo.atlasRect.xy);
GlyphDescriptor glyph = uGlyphs[imageInfo.glyphIndex];
float emsPerUnit = 1.0f / float(glyph.unitsPerEm);
vec2 glyphPos = vec2(aPosition.x - glyphInfo.extents.x, glyphInfo.extents.w - aPosition.y);
vec2 atlasPos = glyphPos * emsPerUnit * imageInfo.pointSize + vec2(imageInfo.atlasRect.xy);
gl_Position = vec4(atlasPos, 0.0f, 1.0f);
}

6
src/batch.rs
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@ -18,7 +18,7 @@ const POINTS_PER_SEGMENT: u32 = 32;
pub struct BatchBuilder {
pub atlas: Atlas,
pub indices: Vec<u16>,
pub indices: Vec<u32>,
pub images: Vec<ImageDescriptor>,
pub point_count: u32,
}
@ -47,10 +47,6 @@ impl BatchBuilder {
let pixel_size = descriptor.pixel_rect(point_size).size.ceil().cast().unwrap();
let atlas_origin = try!(self.atlas.place(&pixel_size));
if self.point_count % POINTS_PER_SEGMENT == 0 {
self.indices.push(self.images.len() as u16)
}
self.images.push(ImageDescriptor {
atlas_x: atlas_origin.x,
atlas_y: atlas_origin.y,

49
src/coverage.rs
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@ -10,21 +10,68 @@
use compute_shader::buffer::Protection;
use compute_shader::device::Device;
use compute_shader::texture::{Format, Texture};
use compute_shader::texture::{ExternalTexture, Format, Texture};
use euclid::size::Size2D;
use gl::types::{GLint, GLuint};
use gl;
use std::mem;
pub struct CoverageBuffer {
pub texture: Texture,
pub framebuffer: GLuint,
}
impl CoverageBuffer {
pub fn new(device: &Device, size: &Size2D<u32>) -> Result<CoverageBuffer, ()> {
let texture = try!(device.create_texture(Format::R32F, Protection::ReadWrite, size)
.map_err(drop));
let mut framebuffer = 0;
unsafe {
let mut gl_texture = 0;
gl::GenTextures(1, &mut gl_texture);
try!(texture.bind_to(&ExternalTexture::Gl(gl_texture)).map_err(drop));
gl::BindTexture(gl::TEXTURE_RECTANGLE, gl_texture);
gl::TexParameteri(gl::TEXTURE_RECTANGLE, gl::TEXTURE_MIN_FILTER, gl::LINEAR as GLint);
gl::TexParameteri(gl::TEXTURE_RECTANGLE, gl::TEXTURE_MAG_FILTER, gl::LINEAR as GLint);
gl::TexParameteri(gl::TEXTURE_RECTANGLE,
gl::TEXTURE_WRAP_S,
gl::CLAMP_TO_EDGE as GLint);
gl::TexParameteri(gl::TEXTURE_RECTANGLE,
gl::TEXTURE_WRAP_T,
gl::CLAMP_TO_EDGE as GLint);
gl::GenFramebuffers(1, &mut framebuffer);
gl::BindFramebuffer(gl::FRAMEBUFFER, framebuffer);
gl::FramebufferTexture2D(gl::FRAMEBUFFER,
gl::COLOR_ATTACHMENT0,
gl::TEXTURE_RECTANGLE,
gl_texture,
0);
}
Ok(CoverageBuffer {
texture: texture,
framebuffer: framebuffer,
})
}
}
impl Drop for CoverageBuffer {
fn drop(&mut self) {
unsafe {
let mut gl_texture = 0;
gl::BindFramebuffer(gl::FRAMEBUFFER, self.framebuffer);
gl::GetFramebufferAttachmentParameteriv(gl::FRAMEBUFFER,
gl::COLOR_ATTACHMENT0,
gl::FRAMEBUFFER_ATTACHMENT_OBJECT_NAME,
&mut gl_texture as *mut GLuint as *mut GLint);
gl::DeleteTextures(1, &mut gl_texture);
gl::BindFramebuffer(gl::FRAMEBUFFER, 0);
gl::DeleteFramebuffers(1, &mut self.framebuffer);
}
}
}

85
src/glyph_buffer.rs
View File

@ -11,12 +11,21 @@
use compute_shader::buffer::{Buffer, BufferData, HostAllocatedData, Protection};
use compute_shader::device::Device;
use euclid::{Point2D, Rect, Size2D};
use gl::types::{GLsizeiptr, GLuint};
use gl;
use otf::glyf::GlyfTable;
use otf::head::HeadTable;
use otf::loca::LocaTable;
use std::mem;
use std::os::raw::c_void;
pub struct GlyphBufferBuilder {
pub coordinates: Vec<(i16, i16)>,
/// TODO(pcwalton): Try omitting this and binary search the glyph descriptors in the vertex
/// shader. Might or might not help.
pub glyph_indices: Vec<u16>,
pub operations: Vec<u8>,
pub descriptors: Vec<GlyphDescriptor>,
}
@ -26,6 +35,7 @@ impl GlyphBufferBuilder {
pub fn new() -> GlyphBufferBuilder {
GlyphBufferBuilder {
coordinates: vec![],
glyph_indices: vec![],
operations: vec![],
descriptors: vec![],
}
@ -37,6 +47,8 @@ impl GlyphBufferBuilder {
loca_table: &LocaTable,
glyf_table: &GlyfTable)
-> Result<(), ()> {
let glyph_index = self.descriptors.len() as u16;
let mut point_index = self.coordinates.len() / 2;
let start_point = point_index;
let mut operations = if point_index % 4 == 0 {
@ -47,6 +59,7 @@ impl GlyphBufferBuilder {
try!(glyf_table.for_each_point(loca_table, glyph_id, |point| {
self.coordinates.push((point.position.x, point.position.y));
self.glyph_indices.push(glyph_index);
let operation = if point.first_point_in_contour {
0
@ -68,50 +81,67 @@ impl GlyphBufferBuilder {
self.operations.push(operations)
}
// TODO(pcwalton): Add a glyph descriptor.
// Add a glyph descriptor.
let bounding_rect = try!(glyf_table.bounding_rect(loca_table, glyph_id));
self.descriptors.push(GlyphDescriptor {
left: bounding_rect.origin.x,
bottom: bounding_rect.origin.y,
width: bounding_rect.size.width,
height: bounding_rect.size.height,
units_per_em: head_table.units_per_em,
point_count: (point_index - start_point) as u16,
left: bounding_rect.origin.x as i32,
bottom: bounding_rect.origin.y as i32,
right: bounding_rect.max_x() as i32,
top: bounding_rect.max_y() as i32,
units_per_em: head_table.units_per_em as u32,
point_count: (point_index - start_point) as u32,
start_point: start_point as u32,
pad: 0,
});
Ok(())
}
pub fn finish(&self, device: &Device) -> Result<GlyphBuffers, ()> {
let coordinates = BufferData::HostAllocated(HostAllocatedData::new(&self.coordinates));
let operations = BufferData::HostAllocated(HostAllocatedData::new(&self.operations));
let descriptors = BufferData::HostAllocated(HostAllocatedData::new(&self.descriptors));
Ok(GlyphBuffers {
coordinates: try!(device.create_buffer(Protection::ReadOnly, coordinates)
.map_err(drop)),
operations: try!(device.create_buffer(Protection::ReadOnly, operations).map_err(drop)),
descriptors: try!(device.create_buffer(Protection::ReadOnly, descriptors)
.map_err(drop)),
})
// TODO(pcwalton): Try using `glMapBuffer` here. Requires precomputing contours.
unsafe {
let (mut coordinates, mut descriptors) = (0, 0);
gl::GenBuffers(1, &mut coordinates);
gl::GenBuffers(1, &mut descriptors);
let length = self.coordinates.len() * mem::size_of::<(i16, i16)>();
gl::BindBuffer(gl::ARRAY_BUFFER, coordinates);
gl::BufferData(gl::ARRAY_BUFFER,
length as GLsizeiptr,
self.coordinates.as_ptr() as *const (i16, i16) as *const c_void,
gl::STATIC_DRAW);
let length = self.descriptors.len() * mem::size_of::<GlyphDescriptor>();
gl::BindBuffer(gl::UNIFORM_BUFFER, descriptors);
gl::BufferData(gl::UNIFORM_BUFFER,
length as GLsizeiptr,
self.descriptors.as_ptr() as *const GlyphDescriptor as *const c_void,
gl::STATIC_DRAW);
Ok(GlyphBuffers {
coordinates: coordinates,
descriptors: descriptors,
})
}
}
}
pub struct GlyphBuffers {
pub coordinates: Buffer,
pub operations: Buffer,
pub descriptors: Buffer,
pub coordinates: GLuint,
pub descriptors: GLuint,
}
#[repr(C)]
#[derive(Clone, Copy)]
pub struct GlyphDescriptor {
pub left: i16,
pub bottom: i16,
pub width: i16,
pub height: i16,
pub units_per_em: u16,
pub point_count: u16,
pub left: i32,
pub bottom: i32,
pub right: i32,
pub top: i32,
pub units_per_em: u32,
pub point_count: u32,
pub start_point: u32,
pub pad: u32,
}
impl GlyphDescriptor {
@ -119,7 +149,8 @@ impl GlyphDescriptor {
pub fn pixel_rect(&self, point_size: f32) -> Rect<f32> {
let pixels_per_unit = point_size / self.units_per_em as f32;
Rect::new(Point2D::new(self.left as f32, self.bottom as f32),
Size2D::new(self.width as f32, self.height as f32)) * pixels_per_unit
Size2D::new((self.right - self.left) as f32,
(self.bottom - self.top) as f32)) * pixels_per_unit
}
}