draw_capture_hi_res example panics when running with opengles backend

[Alan Sartorio]

If I force the draw_capture_hi_res example to use opengles backend like this:

diff

diff --git a/examples/draw/draw_capture_hi_res.rs b/examples/draw/draw_capture_hi_res.rs
index 79635b9..2e90350 100644
--- a/examples/draw/draw_capture_hi_res.rs
+++ b/examples/draw/draw_capture_hi_res.rs
@@ -4,7 +4,7 @@
 use nannou::prelude::*;
 
 fn main() {
-    nannou::app(model).update(update).exit(exit).run();
+    nannou::app(model).backends(wgpu::Backends::GL).update(update).exit(exit).run();
 }
 
 struct Model {

It panics when I run it in release mode

cargo run --example=draw_capture_hi_res --release

output

thread 'main' panicked at 'wgpu error: Validation Error

Caused by:
    In Device::create_render_pipeline
      note: label = `nannou render pipeline`
    Internal error in FRAGMENT shader: 0:19(19): error: no matching function for call to `textureSize(sampler2DMS, int)'; candidates are:
0:19(19): error:    int textureSize(sampler1D, int)
0:19(19): error:    int textureSize(isampler1D, int)
0:19(19): error:    int textureSize(usampler1D, int)
0:19(19): error:    ivec2 textureSize(sampler2D, int)
0:19(19): error:    ivec2 textureSize(isampler2D, int)
0:19(19): error:    ivec2 textureSize(usampler2D, int)
0:19(19): error:    ivec3 textureSize(sampler3D, int)
0:19(19): error:    ivec3 textureSize(isampler3D, int)
0:19(19): error:    ivec3 textureSize(usampler3D, int)
0:19(19): error:    ivec2 textureSize(samplerCube, int)
0:19(19): error:    ivec2 textureSize(isamplerCube, int)
0:19(19): error:    ivec2 textureSize(usamplerCube, int)
0:19(19): error:    int textureSize(sampler1DShadow, int)
0:19(19): error:    ivec2 textureSize(sampler2DShadow, int)
0:19(19): error:    ivec2 textureSize(samplerCubeShadow, int)
0:19(19): error:    ivec2 textureSize(sampler1DArray, int)
0:19(19): error:    ivec2 textureSize(isampler1DArray, int)
0:19(19): error:    ivec2 textureSize(usampler1DArray, int)
0:19(19): error:    ivec3 textureSize(sampler2DArray, int)
0:19(19): error:    ivec3 textureSize(isampler2DArray, int)
0:19(19): error:    ivec3 textureSize(usampler2DArray, int)
0:19(19): error:    ivec2 textureSize(sampler1DArrayShadow, int)
0:19(19): error:    ivec3 textureSize(sampler2DArrayShadow, int)
0:19(19): error:    ivec3 textureSize(samplerCubeArray, int)
0:19(19): error:    ivec3 textureSize(isamplerCubeArray, int)
0:19(19): error:    ivec3 textureSize(usamplerCubeArray, int)
0:19(19): error:    ivec3 textureSize(samplerCubeArrayShadow, int)
0:19(19): error:    ivec2 textureSize(sampler2DRect)
0:19(19): error:    ivec2 textureSize(isampler2DRect)
0:19(19): error:    ivec2 textureSize(usampler2DRect)
0:19(19): error:    ivec2 textureSize(sampler2DRectShadow)
0:19(19): error:    int textureSize(samplerBuffer)
0:19(19): error:    int textureSize(isamplerBuffer)
0:19(19): error:    int textureSize(usamplerBuffer)
0:19(19): error:    ivec2 textureSize(sampler2DMS)
0:19(19): error:    ivec2 textureSize(isampler2DMS)
0:19(19): error:    ivec2 textureSize(usampler2DMS)
0:19(19): error:    ivec3 textureSize(sampler2DMSArray)
0:19(19): error:    ivec3 textureSize(isampler2DMSArray)
0:19(19): error:    ivec3 textureSize(usampler2DMSArray)
0:19(19): error: type mismatch
0:20(25): warning: `tex_size' used uninitialized
0:21(25): warning: `tex_size' used uninitialized


', /home/alan/.cargo/registry/src/index.crates.io-6f17d22bba15001f/wgpu-0.11.1/src/backend/direct.rs:2195:5
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
warning: queue 0x55f66c7f0c20 destroyed while proxies still attached:
  xdg_wm_base@19 still attached
  wl_surface@18 still attached
  wl_output@13 still attached
  xdg_activation_v1@12 still attached
  zwp_text_input_manager_v3@11 still attached
  zwp_relative_pointer_manager_v1@10 still attached
  zwp_pointer_constraints_v1@9 still attached
  zxdg_decoration_manager_v1@8 still attached
  wl_seat@7 still attached
  wl_subcompositor@6 still attached
  wl_compositor@5 still attached
  wl_shm@4 still attached
  wl_registry@2 still attached
[1]    7421 segmentation fault  cargo run --example=draw_capture_hi_res --release

I think the last warning is not relevant to this issue.

When I try running it with x11 winit backend with WINIT_UNIX_BACKEND=x11 cargo run --example=draw_capture_hi_res --release I get:

output

thread 'main' panicked at 'Error in Surface::configure: invalid surface', /home/alan/.cargo/registry/src/index.crates.io-6f17d22bba15001f/wgpu-0.11.1/src/backend/direct.rs:204:9
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace

If I don't apply the change to force GL backend, it uses Vulkan and it works well.