Clamp GL_TEXTURE_MAX_LEVEL to 1 on Android.

This seems to avoid a bug when sampling from GL_TEXTURE_EXTERNAL_OES
textures.

Remove code to avoid sampler objects on when using GLSL ES2 on GL ES3.
This was a speculative workaround that did not help.


Bug: flutter/flutter#23900
Bug: flutter/flutter#24402
Bug: flutter/flutter#24391

Change-Id: Id14080131e49e632949a3bdc2b15f6e3ce97bf93
Reviewed-on: https://skia-review.googlesource.com/c/172978
Commit-Queue: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
Auto-Submit: Brian Salomon <bsalomon@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>

Author: bsalomon

src/gpu/gl/GrGLCaps.cpp

@@ -62,6 +62,7 @@ GrGLCaps::GrGLCaps(const GrContextOptions& contextOptions,
     fUseDrawInsteadOfAllRenderTargetWrites = false;
     fRequiresCullFaceEnableDisableWhenDrawingLinesAfterNonLines = false;
     fDetachStencilFromMSAABuffersBeforeReadPixels = false;
+    fClampMaxTextureLevelToOne = false;
     fProgramBinarySupport = false;
     fSamplerObjectSupport = false;
 
@@ -2740,16 +2741,14 @@ void GrGLCaps::applyDriverCorrectnessWorkarounds(const GrGLContextInfo& ctxInfo,
     }
 #endif
 
-    // There are reports of both Mali and Adreno 3xx Flutter users having issues drawing
-    // videos and other embedded content on older Android versions (6 and earlier) after sampler
-    // objects were enabled. We suspect this may relate to using sampler objects on ES3 with the ES2
-    // shading language. (We may limit the shading language because of issues around
-    // GL_OES_EGL_image_external_essl3 on older Android versions). We suspect this may be an
-    // under tested combination (sampler object + EXTERNAL_OES texture + ES2 shading language).
-    if (kGLES_GrGLStandard == ctxInfo.standard() && ctxInfo.version() >= GR_GL_VER(3, 0) &&
-        ctxInfo.glslGeneration() <= k110_GrGLSLGeneration) {
-        fSamplerObjectSupport = false;
-    }
+#ifdef SK_BUILD_FOR_ANDROID
+    // Older versions of Android have problems with setting GL_TEXTURE_MAX_LEVEL to 0 for
+    // EGL images (or possibly just GL_TEXTURE_EXTERNAL_OES).
+    // If the texture is not MIP mapped (only has level 0) then it should be harmless to use a
+    // GL_TEXTURE_MAX_LEVEL of 1. Such textures are never used with GL_*_MIPMAP_* set for
+    // GL_TEXTURE_MIN_FILTER.
+    fClampMaxTextureLevelToOne = true;
+#endif
 }
 
 void GrGLCaps::onApplyOptionsOverrides(const GrContextOptions& options) {

src/gpu/gl/GrGLCaps.h

@@ -390,6 +390,10 @@ class GrGLCaps : public GrCaps {
         return fDetachStencilFromMSAABuffersBeforeReadPixels;
     }
 
+    // Older Android versions seem to have an issue with setting GL_TEXTURE_MAX_LEVEL to 0
+    // on EGLImage/GL_TEXTURE_EXTERNAL_OES textures.
+    bool clampMaxTextureLevelToOne() const { return fClampMaxTextureLevelToOne; }
+
     // Returns the observed maximum number of instances the driver can handle in a single draw call
     // without crashing, or 'pendingInstanceCount' if this workaround is not necessary.
     // NOTE: the return value may be larger than pendingInstanceCount.
@@ -526,6 +530,7 @@ class GrGLCaps : public GrCaps {
     bool fUseDrawInsteadOfAllRenderTargetWrites : 1;
     bool fRequiresCullFaceEnableDisableWhenDrawingLinesAfterNonLines : 1;
     bool fDetachStencilFromMSAABuffersBeforeReadPixels : 1;
+    bool fClampMaxTextureLevelToOne : 1;
     int fMaxInstancesPerDrawWithoutCrashing;
 
     uint32_t fBlitFramebufferFlags;

src/gpu/gl/GrGLGpu.cpp

@@ -2902,6 +2902,9 @@ void GrGLGpu::bindTexture(int unitIdx, GrSamplerState samplerState, GrGLTexture*
     GrGLTexture::NonSamplerParams newNonSamplerParams;
     newNonSamplerParams.fBaseMipMapLevel = 0;
     newNonSamplerParams.fMaxMipMapLevel = texture->texturePriv().maxMipMapLevel();
+    if (this->glCaps().clampMaxTextureLevelToOne()) {
+        newNonSamplerParams.fMaxMipMapLevel = SkTMax(newNonSamplerParams.fMaxMipMapLevel, 1);
+    }
 
     const GrGLTexture::NonSamplerParams& oldNonSamplerParams = texture->getCachedNonSamplerParams();
     if (this->glCaps().textureSwizzleSupport()) {