Fix no_ssao viewer option

• Fix SSAO still showing despite uSSAOPower being zero using a CPU check and a uniform bool
• Disable SSAO calculation if SSAO is disabled

viewer/glow-extras/viewer/ViewerRenderer.cc

@@ -278,6 +278,8 @@ void glow::viewer::ViewerRenderer::renderSubview(const tg::ivec2& res, tg::ivec2
     // update mipmaps
     subViewData.shadowMapSoft->bind().generateMipmaps();
 
+    auto const ssaoEnabled = bool(scene.ssaoPower > 0.f);
+
     // accumulate multiple frames per frame
     for (auto _ = 0; _ < mAccumPerFrame; ++_)
     {
@@ -373,6 +375,7 @@ void glow::viewer::ViewerRenderer::renderSubview(const tg::ivec2& res, tg::ivec2
         }
 
         // ssao
+        if (ssaoEnabled)
         {
             GLOW_SCOPED(debugGroup, "ssao");
             auto fb = mFramebufferSSAO->bind();
@@ -403,6 +406,11 @@ void glow::viewer::ViewerRenderer::renderSubview(const tg::ivec2& res, tg::ivec2
 
             subViewData.ssaoSampleCount += mSSAOSamples;
         }
+        else
+        {
+            // Jump to min + 1 to allow early outs
+            subViewData.ssaoSampleCount = mMinSSAOCnt + 1;
+        }
 
         // accum
         {
@@ -418,6 +426,7 @@ void glow::viewer::ViewerRenderer::renderSubview(const tg::ivec2& res, tg::ivec2
 
             shader["uAccumCnt"] = subViewData.accumCount;
             shader["uSSAOSamples"] = subViewData.ssaoSampleCount;
+            shader["uEnableSSAO"] = ssaoEnabled;
             shader["uSSAOPower"] = scene.ssaoPower;
 
             shader.setImage(0, subViewData.targetAccum);