Use a dst size threshold for multitexturing images.

TODO: Set thresholds based on GPU in use.

Change-Id: I0aeac596d11ab63922f2df0d76c668b4f8be5353
Reviewed-on: https://skia-review.googlesource.com/77900
Reviewed-by: Robert Phillips <robertphillips@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/src/gpu/GrShaderCaps.cpp b/src/gpu/GrShaderCaps.cpp
index 2d9cd0a39b..65721ee897 100644
--- a/src/gpu/GrShaderCaps.cpp
+++ b/src/gpu/GrShaderCaps.cpp
@@ -68,11 +68,9 @@ GrShaderCaps::GrShaderCaps(const GrContextOptions& options) {
     fMaxCombinedSamplers = 0;
     fAdvBlendEqInteraction = kNotSupported_AdvBlendEqInteraction;
 
-#if GR_TEST_UTILS
-    fDisableImageMultitexturing = options.fDisableImageMultitexturing;
-#else
-    fDisableImageMultitexturing = false;
-#endif
+    // TODO: Default this to 0 and only enable image multitexturing when a "safe" threshold is
+    // known for a GPU class.
+    fDisableImageMultitexturingDstRectAreaThreshold = std::numeric_limits<size_t>::max();
 }
 
 void GrShaderCaps::dumpJSON(SkJSONWriter* writer) const {
@@ -130,7 +128,8 @@ void GrShaderCaps::dumpJSON(SkJSONWriter* writer) const {
     writer->appendS32("Max Combined Samplers", fMaxFragmentSamplers);
     writer->appendString("Advanced blend equation interaction",
                          kAdvBlendEqInteractionStr[fAdvBlendEqInteraction]);
-    writer->appendBool("Disable image multitexturing", fDisableImageMultitexturing);
+    writer->appendU64("Disable image multitexturing dst area threshold",
+                      fDisableImageMultitexturingDstRectAreaThreshold);
 
     writer->endObject();
 }
@@ -138,5 +137,8 @@ void GrShaderCaps::dumpJSON(SkJSONWriter* writer) const {
 void GrShaderCaps::applyOptionsOverrides(const GrContextOptions& options) {
 #if GR_TEST_UTILS
     fDualSourceBlendingSupport = fDualSourceBlendingSupport && !options.fSuppressDualSourceBlending;
+    if (options.fDisableImageMultitexturing) {
+        fDisableImageMultitexturingDstRectAreaThreshold = 0;
+    }
 #endif
 }