glsl-out: Fix feature search in expressions

It was also searching in all entry points instead of only in the current
one.

All samples queries need the ARB_shader_texture_image_samples extension
so we need to check if any samples queries are made and if so request
the extension.

src/back/glsl/features.rs

@@ -36,6 +36,8 @@ bitflags::bitflags! {
  const MULTI_VIEW = 1 << 17;
  /// Fused multiply-add.
  const FMA = 1 << 18;
+ /// Texture samples query
+ const TEXTURE_SAMPLES = 1 << 19;
  }
 }
 
@@ -101,7 +103,10 @@ impl FeaturesManager {
  check_feature!(SAMPLE_VARIABLES, 400, 300);
  check_feature!(DYNAMIC_ARRAY_SIZE, 430, 310);
  check_feature!(MULTI_VIEW, 140, 310);
- check_feature!(FMA, 400, 310);
+ // Only available on glsl core, this means that opengl es can't query the number
+ // of samples in a image and neither do bound checks on the sample argument
+ // of texelFecth
+ check_feature!(TEXTURE_SAMPLES, 150);
 
  // Return an error if there are missing features
  if missing.is_empty() {
@@ -205,11 +210,19 @@ impl FeaturesManager {
  writeln!(out, "#extension GL_EXT_multiview : require")?;
  }
 
- if self.0.contains(Features::FMA) && version.is_es() {
+ if self.0.contains(Features::FMA) && version >= Version::Embedded(310) {
  // https://www.khronos.org/registry/OpenGL/extensions/EXT/EXT_gpu_shader5.txt
  writeln!(out, "#extension GL_EXT_gpu_shader5 : require")?;
  }
 
+ if self.0.contains(Features::TEXTURE_SAMPLES) {
+ // https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_shader_texture_image_samples.txt
+ writeln!(
+ out,
+ "#extension GL_ARB_shader_texture_image_samples : require"
+ )?;
+ }
+
  Ok(())
  }
 }
@@ -363,24 +376,26 @@ impl<'a, W> Writer<'a, W> {
  }
  }
 
- if self.options.version.supports_fma_function() {
- let has_fma = self
- .module
- .functions
- .iter()
- .flat_map(|(_, f)| f.expressions.iter())
- .chain(
- self.module
- .entry_points
- .iter()
- .flat_map(|e| e.function.expressions.iter()),
- )
- .any(|(_, e)| match *e {
- Expression::Math { fun, .. } if fun == MathFunction::Fma => true,
- _ => false,
- });
- if has_fma {
- self.features.request(Features::FMA);
+ // Loop trough all expressions in both functions and entry points
+ // to check for needed features
+ for (_, expr) in self
+ .module
+ .functions
+ .iter()
+ .flat_map(|(_, f)| f.expressions.iter())
+ .chain(self.entry_point.function.expressions.iter())
+ {
+ match *expr {
+ // Check for fused multiply add use
+ Expression::Math { fun, .. } if fun == MathFunction::Fma => {
+ self.features.request(Features::FMA)
+ }
+ // Check for samples query
+ Expression::ImageQuery {
+ query: crate::ImageQuery::NumSamples,
+ ..
+ } => self.features.request(Features::TEXTURE_SAMPLES),
+ _ => {}
  }
  }
 

src/back/glsl/mod.rs

@@ -2433,7 +2433,6 @@ impl<'a, W: Write> Writer<'a, W> {
  }
  }
  crate::ImageQuery::NumSamples => {
- // assumes ARB_shader_texture_image_samples
  let fun_name = match class {
  ImageClass::Sampled { .. } | ImageClass::Depth { .. } => {
  "textureSamples"