[gl] add support for line and point polygon modes

CHANGELOG.md

@@ -57,6 +57,8 @@ Previously, `DeviceExt::create_texture_with_data` only allowed data to be provid
 
 #### OpenGL
 - `@builtin(instance_index)` now properly reflects the range provided in the draw call instead of always counting from 0. By @cwfitzgerald in [#4722](https://github.com/gfx-rs/wgpu/pull/4722).
+- Desktop GL now supports `POLYGON_MODE_LINE` and `POLYGON_MODE_POINT`. By @valaphee in [#4836](https://github.com/gfx-rs/wgpu/pull/4836)
+
 #### Naga
 
 - Naga's WGSL front and back ends now have experimental support for 64-bit floating-point literals: `1.0lf` denotes an `f64` value. There has been experimental support for an `f64` type for a while, but until now there was no syntax for writing literals with that type. As before, Naga module validation rejects `f64` values unless `naga::valid::Capabilities::FLOAT64` is requested. By @jimblandy in [#4747](https://github.com/gfx-rs/wgpu/pull/4747).

wgpu-hal/src/gles/adapter.rs

@@ -219,10 +219,7 @@ impl super::Adapter {
  log::debug!("Version: {}", version);
 
  let full_ver = Self::parse_full_version(&version).ok();
- let es_ver = full_ver
- .is_none()
- .then_some(())
- .and_then(|_| Self::parse_version(&version).ok());
+ let es_ver = full_ver.map_or_else(|| Self::parse_version(&version).ok(), |_| None);
  let web_gl = cfg!(target_arch = "wasm32");
 
  if let Some(full_ver) = full_ver {
@@ -556,6 +553,10 @@ impl super::Adapter {
  || extensions.contains("OES_texture_float_linear"),
  );
 
+ if es_ver.is_none() {
+ features |= wgt::Features::POLYGON_MODE_LINE | wgt::Features::POLYGON_MODE_POINT;
+ }
+
  // We *might* be able to emulate bgra8unorm-storage but currently don't attempt to.
 
  let mut private_caps = super::PrivateCapabilities::empty();

wgpu-hal/src/gles/conv.rs

@@ -285,18 +285,6 @@ pub fn map_primitive_topology(topology: wgt::PrimitiveTopology) -> u32 {
 }
 
 pub(super) fn map_primitive_state(state: &wgt::PrimitiveState) -> super::PrimitiveState {
- match state.polygon_mode {
- wgt::PolygonMode::Fill => {}
- wgt::PolygonMode::Line => panic!(
- "{:?} is not enabled for this backend",
- wgt::Features::POLYGON_MODE_LINE
- ),
- wgt::PolygonMode::Point => panic!(
- "{:?} is not enabled for this backend",
- wgt::Features::POLYGON_MODE_POINT
- ),
- }
-
  super::PrimitiveState {
  //Note: we are flipping the front face, so that
  // the Y-flip in the generated GLSL keeps the same visibility.
@@ -311,6 +299,11 @@ pub(super) fn map_primitive_state(state: &wgt::PrimitiveState) -> super::Primiti
  None => 0,
  },
  unclipped_depth: state.unclipped_depth,
+ polygon_mode: match state.polygon_mode {
+ wgt::PolygonMode::Fill => glow::FILL,
+ wgt::PolygonMode::Line => glow::LINE,
+ wgt::PolygonMode::Point => glow::POINT,
+ },
  }
 }
 

wgpu-hal/src/gles/mod.rs

@@ -736,6 +736,7 @@ struct PrimitiveState {
  front_face: u32,
  cull_face: u32,
  unclipped_depth: bool,
+ polygon_mode: u32,
 }
 
 type InvalidatedAttachments = ArrayVec<u32, { crate::MAX_COLOR_ATTACHMENTS + 2 }>;

wgpu-hal/src/gles/queue.rs

@@ -1330,6 +1330,10 @@ impl super::Queue {
  unsafe { gl.disable(glow::DEPTH_CLAMP) };
  }
  }
+ // POLYGON_MODE_LINE also implies POLYGON_MODE_POINT
+ if self.features.contains(wgt::Features::POLYGON_MODE_LINE) {
+ unsafe { gl.polygon_mode(glow::FRONT_AND_BACK, state.polygon_mode) };
+ }
  }
  C::SetBlendConstant(c) => {
  unsafe { gl.blend_color(c[0], c[1], c[2], c[3]) };