Revert of Support GL_SAMPLES queries in null contexts

src/gpu/gl/GrGLCreateNullInterface.cpp

Index: src/gpu/gl/GrGLCreateNullInterface.cpp
diff --git a/src/gpu/gl/GrGLCreateNullInterface.cpp b/src/gpu/gl/GrGLCreateNullInterface.cpp
index da8e6b3862660a1084256f1efca36071e3bfcaba..efdea2b47fb8eecacee859318359cbd64fe7640b 100644
--- a/src/gpu/gl/GrGLCreateNullInterface.cpp
+++ b/src/gpu/gl/GrGLCreateNullInterface.cpp
@@ -6,97 +6,19 @@
  */
 
 
-#include "GrNonAtomicRef.h"
 #include "gl/GrGLInterface.h"
 #include "GrGLTestInterface.h"
 #include "SkMutex.h"
 #include "SkTDArray.h"
-#include <type_traits>
 
 // added to suppress 'no previous prototype' warning and because this code is duplicated in
 // SkNullGLContext.cpp
 namespace {
 
-class GLObject : public GrNonAtomicRef<GLObject> {
+class BufferObj {
 public:
-    GLObject(GrGLuint id) : fID(id) {}
-    GrGLuint id() const { return fID; }
-
-private:
-    GrGLuint fID;
-};
-
-// This class maintains a sparsely populated array of object pointers.
-template<typename T> class TGLObjectManager {
-   static_assert(std::is_convertible<T*, GLObject*>::value, "T must be a subclass of GLObject");
-
-public:
-    TGLObjectManager() : fFreeListHead(kFreeListEnd) {
-        *fGLObjects.append() = nullptr; // 0 is not a valid GL object id.
-    }
-
-    ~TGLObjectManager() {
-        // nullptr out the entries that are really free list links rather than ptrs before deleting.
-        intptr_t curr = fFreeListHead;
-        while (kFreeListEnd != curr) {
-            intptr_t next = reinterpret_cast<intptr_t>(fGLObjects[SkToS32(curr)]);
-            fGLObjects[SkToS32(curr)] = nullptr;
-            curr = next;
-        }
-
-        fGLObjects.safeUnrefAll();
-    }
-
-    T* lookUp(GrGLuint id) {
-        T* object = fGLObjects[id];
-        SkASSERT(object && object->id() == id);
-        return object;
-    }
-
-    T* create() {
-        GrGLuint id;
-        T* object;
-
-        if (kFreeListEnd == fFreeListHead) {
-            // no free slots - create a new one
-            id = fGLObjects.count();
-            object = new T(id);
-            *fGLObjects.append() = object;
-        } else {
-            // grab the head of the free list and advance the head to the next free slot.
-            id = static_cast<GrGLuint>(fFreeListHead);
-            fFreeListHead = reinterpret_cast<intptr_t>(fGLObjects[id]);
-
-            object = new T(id);
-            fGLObjects[id] = object;
-        }
-
-        return object;
-    }
-
-    void free(T* object) {
-        SkASSERT(object);
-        SkASSERT(fGLObjects.count() > 0);
-
-        GrGLuint id = object->id();
-        object->unref();
-
-        fGLObjects[id] = reinterpret_cast<T*>(fFreeListHead);
-        fFreeListHead = id;
-    }
-
-private:
-    static const intptr_t kFreeListEnd = -1;
-    // Index of the first entry of fGLObjects in the free list. Free slots in fGLObjects are indices
-    // to the next free slot. The last free slot has a value of kFreeListEnd.
-    intptr_t        fFreeListHead;
-    SkTDArray<T*>   fGLObjects;
-};
-
-class Buffer : public GLObject {
-public:
-    Buffer(GrGLuint id) : INHERITED(id), fDataPtr(nullptr), fSize(0), fMapped(false) {}
-    ~Buffer() { delete[] fDataPtr; }
+    BufferObj(GrGLuint id) : fID(id), fDataPtr(nullptr), fSize(0), fMapped(false) {}
+    ~BufferObj() { delete[] fDataPtr; }
 
     void allocate(GrGLsizeiptr size, const GrGLchar* dataPtr) {
         if (fDataPtr) {
@@ -108,6 +30,7 @@
         fDataPtr = new char[size];
     }
 
+    GrGLuint id() const          { return fID; }
     GrGLchar* dataPtr()          { return fDataPtr; }
     GrGLsizeiptr size() const    { return fSize; }
 
@@ -115,119 +38,82 @@
     bool mapped() const          { return fMapped; }
 
 private:
+    GrGLuint     fID;
     GrGLchar*    fDataPtr;
     GrGLsizeiptr fSize;         // size in bytes
     bool         fMapped;
-
-    typedef GLObject INHERITED;
 };
 
-class FramebufferAttachment : public GLObject {
+// This class maintains a sparsely populated array of buffer pointers.
+class BufferManager {
 public:
-    FramebufferAttachment(int id) : INHERITED(id), fNumSamples(1) {}
-    int numSamples() const { return fNumSamples; }
-
-protected:
-    int fNumSamples;
-
-    typedef GLObject INHERITED;
-};
-
-class Renderbuffer : public FramebufferAttachment {
-public:
-    Renderbuffer(int id) : INHERITED(id) {}
-    void setNumSamples(int numSamples) { fNumSamples = numSamples; }
+    BufferManager() : fFreeListHead(kFreeListEnd) {
+        *fBuffers.append() = nullptr; // 0 is not a valid GL buffer id.
+    }
+
+    ~BufferManager() {
+        // nullptr out the entries that are really free list links rather than ptrs before deleting.
+        intptr_t curr = fFreeListHead;
+        while (kFreeListEnd != curr) {
+            intptr_t next = reinterpret_cast<intptr_t>(fBuffers[SkToS32(curr)]);
+            fBuffers[SkToS32(curr)] = nullptr;
+            curr = next;
+        }
+
+        fBuffers.deleteAll();
+    }
+
+    BufferObj* lookUp(GrGLuint id) {
+        BufferObj* buffer = fBuffers[id];
+        SkASSERT(buffer && buffer->id() == id);
+        return buffer;
+    }
+
+    BufferObj* create() {
+        GrGLuint id;
+        BufferObj* buffer;
+
+        if (kFreeListEnd == fFreeListHead) {
+            // no free slots - create a new one
+            id = fBuffers.count();
+            buffer = new BufferObj(id);
+            *fBuffers.append() = buffer;
+        } else {
+            // grab the head of the free list and advance the head to the next free slot.
+            id = static_cast<GrGLuint>(fFreeListHead);
+            fFreeListHead = reinterpret_cast<intptr_t>(fBuffers[id]);
+
+            buffer = new BufferObj(id);
+            fBuffers[id] = buffer;
+        }
+
+        return buffer;
+    }
+
+    void free(BufferObj* buffer) {
+        SkASSERT(buffer);
+        SkASSERT(fBuffers.count() > 0);
+
+        GrGLuint id = buffer->id();
+        delete buffer;
+
+        fBuffers[id] = reinterpret_cast<BufferObj*>(fFreeListHead);
+        fFreeListHead = id;
+    }
 
 private:
-    typedef FramebufferAttachment INHERITED;
-};
-
-class Texture : public FramebufferAttachment {
-public:
-    // We currently only use FramebufferAttachment objects for a sample count, and all textures in
-    // Skia have one sample, so there is no need as of yet to track individual textures. This also
-    // works around a bug in chromium's cc_unittests where they send us texture IDs that were
-    // generated by cc::TestGLES2Interface.
-    static Texture* GetSingleInstance() {
-        static Texture* singleInstance;
-        if (!singleInstance) {
-            singleInstance = new Texture();
-        }
-        return singleInstance;
-    }
-
-private:
-    Texture() : INHERITED(1) {}
-
-    typedef FramebufferAttachment INHERITED;
-};
-
-class Framebuffer : public GLObject {
-public:
-    Framebuffer(int id) : INHERITED(id) {}
-
-    void setAttachment(GrGLenum attachmentPoint, const FramebufferAttachment* attachment) {
-        switch (attachmentPoint) {
-            default:
-                SK_ABORT("Invalid framebuffer attachment.");
-                break;
-            case GR_GL_STENCIL_ATTACHMENT:
-                fAttachments[(int)AttachmentPoint::kStencil].reset(SkRef(attachment));
-                break;
-            case GR_GL_DEPTH_ATTACHMENT:
-                fAttachments[(int)AttachmentPoint::kDepth].reset(SkRef(attachment));
-                break;
-            case GR_GL_COLOR_ATTACHMENT0:
-                fAttachments[(int)AttachmentPoint::kColor].reset(SkRef(attachment));
-                break;
-        }
-    }
-
-    void notifyAttachmentDeleteWhileBound(const FramebufferAttachment* deleted) {
-        for (auto& attachment : fAttachments) {
-            if (attachment == deleted) {
-                attachment.reset(nullptr);
-            }
-        }
-    }
-
-    int numSamples() const {
-        int numSamples = 0;
-        for (auto& attachment : fAttachments) {
-            if (!attachment) {
-                continue;
-            }
-            if (numSamples) {
-                GrAlwaysAssert(attachment->numSamples() == numSamples);
-                continue;
-            }
-            numSamples = attachment->numSamples();
-        }
-        GrAlwaysAssert(numSamples);
-        return numSamples;
-    }
-
-private:
-    enum AttachmentPoint {
-        kStencil,
-        kDepth,
-        kColor
-    };
-    constexpr int static kNumAttachmentPoints = 1 + (int)AttachmentPoint::kColor;
-
-    SkAutoTUnref<const FramebufferAttachment> fAttachments[kNumAttachmentPoints];
-
-    typedef GLObject INHERITED;
+    static const intptr_t kFreeListEnd = -1;
+    // Index of the first entry of fBuffers in the free list. Free slots in fBuffers are indices to
+    // the next free slot. The last free slot has a value of kFreeListEnd.
+    intptr_t                fFreeListHead;
+    SkTDArray<BufferObj*>   fBuffers;
 };
 
 /** Null interface implementation */
 class NullInterface : public GrGLTestInterface {
 public:
     NullInterface(bool enableNVPR)
-        : fCurrDrawFramebuffer(0)
-        , fCurrReadFramebuffer(0)
-        , fCurrRenderbuffer(0)
-        , fCurrProgramID(0)
+        : fCurrProgramID(0)
         , fCurrShaderID(0)
         , fCurrGenericID(0)
         , fCurrUniformLocation(0)
@@ -254,7 +140,7 @@
 
     GrGLvoid genBuffers(GrGLsizei n, GrGLuint* ids) override {
         for (int i = 0; i < n; ++i) {
-            Buffer* buffer = fBufferManager.create();
+            BufferObj* buffer = fBufferManager.create();
             ids[i] = buffer->id();
         }
     }
@@ -263,7 +149,7 @@
                         GrGLenum usage) override {
         GrGLuint id = fBoundBuffers[GetBufferIndex(target)];
         if (id > 0) {
-            Buffer* buffer = fBufferManager.lookUp(id);
+            BufferObj* buffer = fBufferManager.lookUp(id);
             buffer->allocate(size, (const GrGLchar*) data);
         }
     }
@@ -298,166 +184,24 @@
         // Then actually "delete" the buffers.
         for (int i = 0; i < n; ++i) {
             if (ids[i] > 0) {
-                Buffer* buffer = fBufferManager.lookUp(ids[i]);
+                BufferObj* buffer = fBufferManager.lookUp(ids[i]);
                 fBufferManager.free(buffer);
             }
         }
     }
 
     GrGLvoid genFramebuffers(GrGLsizei n, GrGLuint *framebuffers) override {
-        for (int i = 0; i < n; ++i) {
-            Framebuffer* framebuffer = fFramebufferManager.create();
-            framebuffers[i] = framebuffer->id();
-        }
-    }
-
-    GrGLvoid bindFramebuffer(GrGLenum target, GrGLuint framebuffer) override {
-        SkASSERT(GR_GL_FRAMEBUFFER == target || GR_GL_DRAW_FRAMEBUFFER == target ||
-                 GR_GL_READ_FRAMEBUFFER == target);
-        if (GR_GL_READ_FRAMEBUFFER != target) {
-            fCurrDrawFramebuffer = framebuffer;
-        }
-        if (GR_GL_DRAW_FRAMEBUFFER != target) {
-            fCurrReadFramebuffer = framebuffer;
-        }
-    }
-
-    GrGLvoid deleteFramebuffers(GrGLsizei n, const GrGLuint* ids) override {
-        for (int i = 0; i < n; ++i) {
-            if (ids[i] == fCurrDrawFramebuffer) {
-                fCurrDrawFramebuffer = 0;
-            }
-            if (ids[i] == fCurrReadFramebuffer) {
-                fCurrReadFramebuffer = 0;
-            }
-
-            if (ids[i] > 0) {
-                Framebuffer* framebuffer = fFramebufferManager.lookUp(ids[i]);
-                fFramebufferManager.free(framebuffer);
-            }
-        }
+        this->genGenericIds(n, framebuffers);
     }
 
     GrGLvoid genQueries(GrGLsizei n, GrGLuint *ids) override { this->genGenericIds(n, ids); }
 
     GrGLvoid genRenderbuffers(GrGLsizei n, GrGLuint *renderbuffers) override {
-        for (int i = 0; i < n; ++i) {
-            Renderbuffer* renderbuffer = fRenderbufferManager.create();
-            renderbuffers[i] = renderbuffer->id();
-        }
-    }
-
-    GrGLvoid bindRenderbuffer(GrGLenum target, GrGLuint renderbuffer) override {
-        SkASSERT(GR_GL_RENDERBUFFER == target);
-        fCurrRenderbuffer = renderbuffer;
-    }
-
-    GrGLvoid deleteRenderbuffers(GrGLsizei n, const GrGLuint* ids) override {
-        for (int i = 0; i < n; ++i) {
-            if (ids[i] <= 0) {
-                continue;
-            }
-            if (ids[i] == fCurrRenderbuffer) {
-                fCurrRenderbuffer = 0;
-            }
-            Renderbuffer* renderbuffer = fRenderbufferManager.lookUp(ids[i]);
-
-            if (fCurrDrawFramebuffer) {
-                Framebuffer* drawFramebuffer = fFramebufferManager.lookUp(fCurrDrawFramebuffer);
-                drawFramebuffer->notifyAttachmentDeleteWhileBound(renderbuffer);
-            }
-            if (fCurrReadFramebuffer) {
-                Framebuffer* readFramebuffer = fFramebufferManager.lookUp(fCurrReadFramebuffer);
-                readFramebuffer->notifyAttachmentDeleteWhileBound(renderbuffer);
-            }
-
-            fRenderbufferManager.free(renderbuffer);
-        }
-    }
-
-    GrGLvoid renderbufferStorage(GrGLenum target, GrGLenum internalformat, GrGLsizei width,
-                                 GrGLsizei height) override {
-        GrAlwaysAssert(GR_GL_RENDERBUFFER == target);
-        GrAlwaysAssert(fCurrRenderbuffer);
-        Renderbuffer* renderbuffer = fRenderbufferManager.lookUp(fCurrRenderbuffer);
-        renderbuffer->setNumSamples(1);
-    }
-
-    GrGLvoid renderbufferStorageMultisample(GrGLenum target, GrGLsizei samples,
-                                            GrGLenum internalformat, GrGLsizei width,
-                                            GrGLsizei height) override {
-        GrAlwaysAssert(GR_GL_RENDERBUFFER == target);
-        GrAlwaysAssert(samples > 0);
-        GrAlwaysAssert(fCurrRenderbuffer);
-        Renderbuffer* renderbuffer = fRenderbufferManager.lookUp(fCurrRenderbuffer);
-        renderbuffer->setNumSamples(samples);
-    }
-
-    GrGLvoid namedRenderbufferStorage(GrGLuint renderbuffer, GrGLenum GrGLinternalformat,
-                                      GrGLsizei width, GrGLsizei height) override {
-        SK_ABORT("Not implemented");
-    }
-
-    GrGLvoid namedRenderbufferStorageMultisample(GrGLuint renderbuffer, GrGLsizei samples,
-                                                 GrGLenum GrGLinternalformat, GrGLsizei width,
-                                                 GrGLsizei height) override {
-        SK_ABORT("Not implemented");
-    }
-
-    GrGLvoid framebufferRenderbuffer(GrGLenum target, GrGLenum attachment,
-                                     GrGLenum renderbuffertarget,
-                                     GrGLuint renderBufferID) override {
-        GrGLuint id = this->getBoundFramebufferID(target);
-        GrAlwaysAssert(id);
-        Framebuffer* framebuffer = fFramebufferManager.lookUp(id);
-
-        GrAlwaysAssert(GR_GL_RENDERBUFFER == renderbuffertarget);
-        GrAlwaysAssert(fCurrRenderbuffer);
-        Renderbuffer* renderbuffer = fRenderbufferManager.lookUp(fCurrRenderbuffer);
-
-        framebuffer->setAttachment(attachment, renderbuffer);
-    }
-
-    GrGLvoid namedFramebufferRenderbuffer(GrGLuint framebuffer, GrGLenum attachment,
-                                          GrGLenum renderbuffertarget,
-                                          GrGLuint renderbuffer) override {
-        SK_ABORT("Not implemented");
+        this->genGenericIds(n, renderbuffers);
     }
 
     GrGLvoid genTextures(GrGLsizei n, GrGLuint *textures) override {
         this->genGenericIds(n, textures);
-    }
-
-    GrGLvoid framebufferTexture2D(GrGLenum target, GrGLenum attachment, GrGLenum textarget,
-                                  GrGLuint textureID, GrGLint level) override {
-        GrGLuint id = this->getBoundFramebufferID(target);
-        GrAlwaysAssert(id);
-        Framebuffer* framebuffer = fFramebufferManager.lookUp(id);
-        framebuffer->setAttachment(attachment, Texture::GetSingleInstance());
-    }
-
-    GrGLvoid framebufferTexture2DMultisample(GrGLenum target, GrGLenum attachment,
-                                             GrGLenum textarget, GrGLuint texture, GrGLint level,
-                                             GrGLsizei samples) override {
-        SK_ABORT("Not implemented");
-    }
-
-    GrGLvoid namedFramebufferTexture1D(GrGLuint framebuffer, GrGLenum attachment,
-                                       GrGLenum textarget, GrGLuint texture,
-                                       GrGLint level) override {
-        SK_ABORT("Not implemented");
-    }
-
-    GrGLvoid namedFramebufferTexture2D(GrGLuint framebuffer, GrGLenum attachment,
-                                       GrGLenum textarget, GrGLuint texture,
-                                       GrGLint level) override {
-        SK_ABORT("Not implemented");
-    }
-
-    GrGLvoid namedFramebufferTexture3D(GrGLuint framebuffer, GrGLenum attachment,
-                                       GrGLenum textarget, GrGLuint texture, GrGLint level,
-                                       GrGLint zoffset) override {
-        SK_ABORT("Not implemented");
     }
 
     GrGLvoid genVertexArrays(GrGLsizei n, GrGLuint *arrays) override {
@@ -476,12 +220,9 @@
             case GR_GL_STENCIL_BITS:
                 *params = 8;
                 break;
-            case GR_GL_SAMPLES: {
-                GrAlwaysAssert(fCurrDrawFramebuffer);
-                Framebuffer* framebuffer = fFramebufferManager.lookUp(fCurrDrawFramebuffer);
-                *params = framebuffer->numSamples();
-                break;
-            }
+            case GR_GL_SAMPLES:
+                *params = 1;
+                break;
             case GR_GL_FRAMEBUFFER_BINDING:
                 *params = 0;
                 break;
@@ -635,7 +376,7 @@
         GrGLuint id = fBoundBuffers[GetBufferIndex(target)];
         if (id > 0) {
             // We just ignore the offset and length here.
-            Buffer* buffer = fBufferManager.lookUp(id);
+            BufferObj* buffer = fBufferManager.lookUp(id);
             SkASSERT(!buffer->mapped());
             buffer->setMapped(true);
             return buffer->dataPtr();
@@ -646,7 +387,7 @@
     GrGLvoid* mapBuffer(GrGLenum target, GrGLenum access) override {
         GrGLuint id = fBoundBuffers[GetBufferIndex(target)];
         if (id > 0) {
-            Buffer* buffer = fBufferManager.lookUp(id);
+            BufferObj* buffer = fBufferManager.lookUp(id);
             SkASSERT(!buffer->mapped());
             buffer->setMapped(true);
             return buffer->dataPtr();
@@ -659,7 +400,7 @@
     GrGLboolean unmapBuffer(GrGLenum target) override {
         GrGLuint id = fBoundBuffers[GetBufferIndex(target)];
         if (id > 0) {
-            Buffer* buffer = fBufferManager.lookUp(id);
+            BufferObj* buffer = fBufferManager.lookUp(id);
             SkASSERT(buffer->mapped());
             buffer->setMapped(false);
             return GR_GL_TRUE;
@@ -675,7 +416,7 @@
                 *params = GR_GL_FALSE;
                 GrGLuint id = fBoundBuffers[GetBufferIndex(target)];
                 if (id > 0) {
-                    Buffer* buffer = fBufferManager.lookUp(id);
+                    BufferObj* buffer = fBufferManager.lookUp(id);
                     if (buffer->mapped()) {
                         *params = GR_GL_TRUE;
                     }
@@ -707,19 +448,14 @@
     }
     constexpr int static kNumBufferTargets = 6;
 
-    TGLObjectManager<Buffer>         fBufferManager;
-    GrGLuint                         fBoundBuffers[kNumBufferTargets];
-    TGLObjectManager<Framebuffer>    fFramebufferManager;
-    GrGLuint                         fCurrDrawFramebuffer;
-    GrGLuint                         fCurrReadFramebuffer;
-    TGLObjectManager<Renderbuffer>   fRenderbufferManager;
-    GrGLuint                         fCurrRenderbuffer;
-    GrGLuint                         fCurrProgramID;
-    GrGLuint                         fCurrShaderID;
-    GrGLuint                         fCurrGenericID;
-    GrGLuint                         fCurrUniformLocation;
-    GrGLuint                         fCurrPathID;
-    SkTArray<const char*>            fExtensions;
+    BufferManager          fBufferManager;
+    GrGLuint               fBoundBuffers[kNumBufferTargets];
+    GrGLuint               fCurrProgramID;
+    GrGLuint               fCurrShaderID;
+    GrGLuint               fCurrGenericID;
+    GrGLuint               fCurrUniformLocation;
+    GrGLuint               fCurrPathID;
+    SkTArray<const char*>  fExtensions;
 
     // the OpenGLES 2.0 spec says this must be >= 128
     static const GrGLint kDefaultMaxVertexUniformVectors = 128;
@@ -732,19 +468,6 @@
 
     // the OpenGLES 2.0 spec says this must be >= 8
     static const GrGLint kDefaultMaxVaryingVectors = 8;
-
-    GrGLuint getBoundFramebufferID(GrGLenum target) {
-        switch (target) {
-            case GR_GL_FRAMEBUFFER:
-            case GR_GL_DRAW_FRAMEBUFFER:
-                return fCurrDrawFramebuffer;
-            case GR_GL_READ_FRAMEBUFFER:
-                return fCurrReadFramebuffer;
-            default:
-                SK_ABORT("Invalid framebuffer target.");
-                return 0;
-        }
-    }
 
     const GrGLubyte* CombinedExtensionString() {
         static SkString gExtString;