Revert "Revert "Revert "Revert "Redefine the meaning of sample counts in GPU backend.""""

This reverts commit 18c52a7b52211de5d0dcd86dc048adef758c6c75.

Also relands "More sample count cleanup:" and "Add new GrContext queries for imagability, surfacability, and max sample count of color types"


Bug: skia:
Change-Id: I4028105a3a1f16ce3944e134619eb6245af6b947
Reviewed-on: https://skia-review.googlesource.com/102940
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

23 files changed, 56 insertions, 49 deletions

diff --git a/tools/fiddle/fiddle_main.cpp b/tools/fiddle/fiddle_main.cpp
index 4ba84f38ca..684bc2ae48 100644
--- a/tools/fiddle/fiddle_main.cpp
+++ b/tools/fiddle/fiddle_main.cpp
@@ -133,7 +133,7 @@ static bool setup_backend_objects(GrContext* context,
     backingDesc.fHeight = bm.height();
     // This config must match the SkColorType used in draw.cpp in the SkImage and Surface factories
     backingDesc.fConfig = kRGBA_8888_GrPixelConfig;
-    backingDesc.fSampleCnt = 0;
+    backingDesc.fSampleCnt = 1;
 
     if (!bm.empty()) {
         SkPixmap originalPixmap;
diff --git a/tools/flags/SkCommonFlagsConfig.cpp b/tools/flags/SkCommonFlagsConfig.cpp
index d38d70a1dc..9d1c2ddadd 100644
--- a/tools/flags/SkCommonFlagsConfig.cpp
+++ b/tools/flags/SkCommonFlagsConfig.cpp
@@ -391,7 +391,7 @@ SkCommandLineConfigGpu* parse_command_line_config_gpu(const SkString& tag,
     bool seenUseDIText =false;
     bool useDIText = false;
     bool seenSamples = false;
-    int samples = 0;
+    int samples = 1;
     bool seenColor = false;
     SkColorType colorType = kRGBA_8888_SkColorType;
     SkAlphaType alphaType = kPremul_SkAlphaType;
diff --git a/tools/gpu/GrTest.cpp b/tools/gpu/GrTest.cpp
index 829ddcbe89..06d9b831a5 100644
--- a/tools/gpu/GrTest.cpp
+++ b/tools/gpu/GrTest.cpp
@@ -182,6 +182,13 @@ void GrGpu::Stats::dumpKeyValuePairs(SkTArray<SkString>* keys, SkTArray<double>*
 
 #endif
 
+GrBackendTexture GrGpu::createTestingOnlyBackendTexture(void* pixels, int w, int h,
+                                                        SkColorType colorType, bool isRenderTarget,
+                                                        GrMipMapped mipMapped) {
+    GrPixelConfig config = SkImageInfo2GrPixelConfig(colorType, nullptr, *this->caps());
+    return this->createTestingOnlyBackendTexture(pixels, w, h, config, isRenderTarget, mipMapped);
+}
+
 #if GR_CACHE_STATS
 void GrResourceCache::getStats(Stats* stats) const {
     stats->reset();
diff --git a/tools/sk_app/DisplayParams.h b/tools/sk_app/DisplayParams.h
index 959735e8ff..203e8bdeca 100644
--- a/tools/sk_app/DisplayParams.h
+++ b/tools/sk_app/DisplayParams.h
@@ -13,10 +13,7 @@
 namespace sk_app {
 
 struct DisplayParams {
-    DisplayParams()
-        : fColorType(kN32_SkColorType)
-        , fColorSpace(nullptr)
-        , fMSAASampleCount(0) {}
+    DisplayParams() : fColorType(kN32_SkColorType), fColorSpace(nullptr), fMSAASampleCount(1) {}
 
     SkColorType         fColorType;
     sk_sp<SkColorSpace> fColorSpace;
diff --git a/tools/sk_app/GLWindowContext.cpp b/tools/sk_app/GLWindowContext.cpp
index 9ef5141fee..9d042cf19e 100644
--- a/tools/sk_app/GLWindowContext.cpp
+++ b/tools/sk_app/GLWindowContext.cpp
@@ -24,9 +24,7 @@ GLWindowContext::GLWindowContext(const DisplayParams& params)
     : WindowContext(params)
     , fBackendContext(nullptr)
     , fSurface(nullptr) {
-    fDisplayParams.fMSAASampleCount = fDisplayParams.fMSAASampleCount ?
-                                      GrNextPow2(fDisplayParams.fMSAASampleCount) :
-                                      0;
+    fDisplayParams.fMSAASampleCount = GrNextPow2(fDisplayParams.fMSAASampleCount);
 }
 
 void GLWindowContext::initializeContext() {
@@ -34,7 +32,7 @@ void GLWindowContext::initializeContext() {
 
     fBackendContext = this->onInitializeContext();
     fContext = GrContext::MakeGL(fBackendContext, fDisplayParams.fGrContextOptions);
-    if (!fContext && fDisplayParams.fMSAASampleCount) {
+    if (!fContext && fDisplayParams.fMSAASampleCount > 1) {
         fDisplayParams.fMSAASampleCount /= 2;
         this->initializeContext();
         return;
diff --git a/tools/sk_app/Window.cpp b/tools/sk_app/Window.cpp
index 29e4864ba1..1694beaac8 100644
--- a/tools/sk_app/Window.cpp
+++ b/tools/sk_app/Window.cpp
@@ -117,7 +117,7 @@ void Window::setRequestedDisplayParams(const DisplayParams& params, bool /* allo
 
 int Window::sampleCount() const {
     if (!fWindowContext) {
-        return -1;
+        return 0;
     }
     return fWindowContext->sampleCount();
 }
diff --git a/tools/sk_app/WindowContext.h b/tools/sk_app/WindowContext.h
index 5e7d76d4ba..71c21ac089 100644
--- a/tools/sk_app/WindowContext.h
+++ b/tools/sk_app/WindowContext.h
@@ -21,11 +21,11 @@ namespace sk_app {
 class WindowContext {
 public:
     WindowContext(const DisplayParams& params)
-        : fContext(nullptr)
-        , fDisplayParams(params)
-        , fSurfaceProps(SkSurfaceProps::kLegacyFontHost_InitType)
-        , fSampleCount(0)
-        , fStencilBits(0) {}
+            : fContext(nullptr)
+            , fDisplayParams(params)
+            , fSurfaceProps(SkSurfaceProps::kLegacyFontHost_InitType)
+            , fSampleCount(1)
+            , fStencilBits(0) {}
 
     virtual ~WindowContext() {}
 
diff --git a/tools/sk_app/android/GLWindowContext_android.cpp b/tools/sk_app/android/GLWindowContext_android.cpp
index acdb587230..5111114115 100644
--- a/tools/sk_app/android/GLWindowContext_android.cpp
+++ b/tools/sk_app/android/GLWindowContext_android.cpp
@@ -70,6 +70,8 @@ sk_sp<const GrGLInterface> GLWindowContext_android::onInitializeContext() {
     SkAssertResult(eglBindAPI(EGL_OPENGL_ES_API));
 
     EGLint numConfigs = 0;
+    EGLint eglSampleCnt = fDisplayParams.fMSAASampleCount > 1 ? fDisplayParams.fMSAASampleCount > 1
+                                                              : 0;
     const EGLint configAttribs[] = {
         EGL_SURFACE_TYPE, EGL_PBUFFER_BIT,
         EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
@@ -78,8 +80,8 @@ sk_sp<const GrGLInterface> GLWindowContext_android::onInitializeContext() {
         EGL_BLUE_SIZE, 8,
         EGL_ALPHA_SIZE, 8,
         EGL_STENCIL_SIZE, 8,
-        EGL_SAMPLE_BUFFERS, fDisplayParams.fMSAASampleCount ? 1 : 0,
-        EGL_SAMPLES, fDisplayParams.fMSAASampleCount,
+        EGL_SAMPLE_BUFFERS, eglSampleCnt ? 1 : 0,
+        EGL_SAMPLES, eglSampleCnt,
         EGL_NONE
     };
 
@@ -131,6 +133,7 @@ sk_sp<const GrGLInterface> GLWindowContext_android::onInitializeContext() {
 
     eglGetConfigAttrib(fDisplay, surfaceConfig, EGL_STENCIL_SIZE, &fStencilBits);
     eglGetConfigAttrib(fDisplay, surfaceConfig, EGL_SAMPLES, &fSampleCount);
+    fSampleCount = SkTMax(fSampleCount, 1);
 
     return GrGLMakeNativeInterface();
 }
diff --git a/tools/sk_app/ios/GLWindowContext_ios.cpp b/tools/sk_app/ios/GLWindowContext_ios.cpp
index f4c0d6b3c0..2a57b33e30 100644
--- a/tools/sk_app/ios/GLWindowContext_ios.cpp
+++ b/tools/sk_app/ios/GLWindowContext_ios.cpp
@@ -67,6 +67,7 @@ sk_sp<const GrGLInterface> GLWindowContext_ios::onInitializeContext() {
 
         SDL_GL_GetAttribute(SDL_GL_STENCIL_SIZE, &fStencilBits);
         SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &fSampleCount);
+        fSampleCount = SkTMax(fSampleCount, 1);
 
         SDL_GL_GetDrawableSize(fWindow, &fWidth, &fHeight);
         glViewport(0, 0, fWidth, fHeight);
diff --git a/tools/sk_app/ios/RasterWindowContext_ios.cpp b/tools/sk_app/ios/RasterWindowContext_ios.cpp
index cae5774c28..53d7c1a372 100644
--- a/tools/sk_app/ios/RasterWindowContext_ios.cpp
+++ b/tools/sk_app/ios/RasterWindowContext_ios.cpp
@@ -79,6 +79,7 @@ sk_sp<const GrGLInterface> RasterWindowContext_ios::onInitializeContext() {
 
         SDL_GL_GetAttribute(SDL_GL_STENCIL_SIZE, &fStencilBits);
         SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &fSampleCount);
+        fSampleCount = SkTMax(fSampleCount, 1);
 
         SDL_GL_GetDrawableSize(fWindow, &fWidth, &fHeight);
         glViewport(0, 0, fWidth, fHeight);
diff --git a/tools/sk_app/ios/Window_ios.cpp b/tools/sk_app/ios/Window_ios.cpp
index c1bdeae5fc..ac0ad0caa0 100644
--- a/tools/sk_app/ios/Window_ios.cpp
+++ b/tools/sk_app/ios/Window_ios.cpp
@@ -49,7 +49,7 @@ bool Window_ios::initWindow() {
 
     SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, 1);
 
-    if (fRequestedDisplayParams.fMSAASampleCount > 0) {
+    if (fRequestedDisplayParams.fMSAASampleCount > 1) {
         SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
         SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, fRequestedDisplayParams.fMSAASampleCount);
     } else {
diff --git a/tools/sk_app/ios/Window_ios.h b/tools/sk_app/ios/Window_ios.h
index 667fa74e82..a0fed90697 100644
--- a/tools/sk_app/ios/Window_ios.h
+++ b/tools/sk_app/ios/Window_ios.h
@@ -18,11 +18,7 @@ namespace sk_app {
 
 class Window_ios : public Window {
 public:
-    Window_ios()
-        : INHERITED()
-        , fWindow(nullptr)
-        , fWindowID(0)
-        , fMSAASampleCount(0) {}
+    Window_ios() : INHERITED(), fWindow(nullptr), fWindowID(0), fMSAASampleCount(1) {}
     ~Window_ios() override { this->closeWindow(); }
 
     bool initWindow();
diff --git a/tools/sk_app/mac/GLWindowContext_mac.cpp b/tools/sk_app/mac/GLWindowContext_mac.cpp
index 005fc07df4..67fb853fee 100644
--- a/tools/sk_app/mac/GLWindowContext_mac.cpp
+++ b/tools/sk_app/mac/GLWindowContext_mac.cpp
@@ -67,6 +67,7 @@ sk_sp<const GrGLInterface> GLWindowContext_mac::onInitializeContext() {
 
         SDL_GL_GetAttribute(SDL_GL_STENCIL_SIZE, &fStencilBits);
         SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &fSampleCount);
+        fSampleCount = SkTMax(fSampleCount, 1);
 
         SDL_GetWindowSize(fWindow, &fWidth, &fHeight);
         glViewport(0, 0, fWidth, fHeight);
diff --git a/tools/sk_app/mac/RasterWindowContext_mac.cpp b/tools/sk_app/mac/RasterWindowContext_mac.cpp
index 67022af7fe..fbe9837911 100644
--- a/tools/sk_app/mac/RasterWindowContext_mac.cpp
+++ b/tools/sk_app/mac/RasterWindowContext_mac.cpp
@@ -79,6 +79,7 @@ sk_sp<const GrGLInterface> RasterWindowContext_mac::onInitializeContext() {
 
         SDL_GL_GetAttribute(SDL_GL_STENCIL_SIZE, &fStencilBits);
         SDL_GL_GetAttribute(SDL_GL_MULTISAMPLESAMPLES, &fSampleCount);
+        fSampleCount = SkTMax(fSampleCount, 1);
 
         SDL_GetWindowSize(fWindow, &fWidth, &fHeight);
         glViewport(0, 0, fWidth, fHeight);
diff --git a/tools/sk_app/mac/Window_mac.cpp b/tools/sk_app/mac/Window_mac.cpp
index 8de5b10450..f2620518a2 100644
--- a/tools/sk_app/mac/Window_mac.cpp
+++ b/tools/sk_app/mac/Window_mac.cpp
@@ -49,7 +49,7 @@ bool Window_mac::initWindow() {
 
     SDL_GL_SetAttribute(SDL_GL_ACCELERATED_VISUAL, 1);
 
-    if (fRequestedDisplayParams.fMSAASampleCount > 0) {
+    if (fRequestedDisplayParams.fMSAASampleCount > 1) {
         SDL_GL_SetAttribute(SDL_GL_MULTISAMPLEBUFFERS, 1);
         SDL_GL_SetAttribute(SDL_GL_MULTISAMPLESAMPLES, fRequestedDisplayParams.fMSAASampleCount);
     } else {
diff --git a/tools/sk_app/mac/Window_mac.h b/tools/sk_app/mac/Window_mac.h
index aa5c8df696..35cba095fa 100644
--- a/tools/sk_app/mac/Window_mac.h
+++ b/tools/sk_app/mac/Window_mac.h
@@ -18,11 +18,7 @@ namespace sk_app {
 
 class Window_mac : public Window {
 public:
-    Window_mac()
-        : INHERITED()
-        , fWindow(nullptr)
-        , fWindowID(0)
-        , fMSAASampleCount(0) {}
+    Window_mac() : INHERITED(), fWindow(nullptr), fWindowID(0), fMSAASampleCount(1) {}
     ~Window_mac() override { this->closeWindow(); }
 
     bool initWindow();
diff --git a/tools/sk_app/unix/GLWindowContext_unix.cpp b/tools/sk_app/unix/GLWindowContext_unix.cpp
index 25ec95cdd6..3a3a4b16d4 100644
--- a/tools/sk_app/unix/GLWindowContext_unix.cpp
+++ b/tools/sk_app/unix/GLWindowContext_unix.cpp
@@ -99,6 +99,7 @@ sk_sp<const GrGLInterface> GLWindowContext_xlib::onInitializeContext() {
 
     glXGetConfig(fDisplay, fVisualInfo, GLX_STENCIL_SIZE, &fStencilBits);
     glXGetConfig(fDisplay, fVisualInfo, GLX_SAMPLES_ARB, &fSampleCount);
+    fSampleCount = SkTMax(fSampleCount, 1);
 
     XWindow root;
     int x, y;
diff --git a/tools/sk_app/unix/Window_unix.cpp b/tools/sk_app/unix/Window_unix.cpp
index f5ca5ee073..745b4dd3fb 100644
--- a/tools/sk_app/unix/Window_unix.cpp
+++ b/tools/sk_app/unix/Window_unix.cpp
@@ -72,7 +72,7 @@ bool Window_unix::initWindow(Display* display) {
         None
     };
     SkASSERT(nullptr == fVisualInfo);
-    if (fRequestedDisplayParams.fMSAASampleCount > 0) {
+    if (fRequestedDisplayParams.fMSAASampleCount > 1) {
         static const GLint kChooseFBConifgAttCnt = SK_ARRAY_COUNT(kChooseFBConfigAtt);
         GLint msaaChooseFBConfigAtt[kChooseFBConifgAttCnt + 4];
         memcpy(msaaChooseFBConfigAtt, kChooseFBConfigAtt, sizeof(kChooseFBConfigAtt));
diff --git a/tools/sk_app/unix/Window_unix.h b/tools/sk_app/unix/Window_unix.h
index b59f502eb9..62a2795098 100644
--- a/tools/sk_app/unix/Window_unix.h
+++ b/tools/sk_app/unix/Window_unix.h
@@ -20,13 +20,14 @@ namespace sk_app {
 
 class Window_unix : public Window {
 public:
-    Window_unix() : Window()
-                  , fDisplay(nullptr)
-                  , fWindow(0)
-                  , fGC(nullptr)
-                  , fFBConfig(nullptr)
-                  , fVisualInfo(nullptr)
-                  , fMSAASampleCount(0) {}
+    Window_unix()
+            : Window()
+            , fDisplay(nullptr)
+            , fWindow(0)
+            , fGC(nullptr)
+            , fFBConfig(nullptr)
+            , fVisualInfo(nullptr)
+            , fMSAASampleCount(1) {}
     ~Window_unix() override { this->closeWindow(); }
 
     bool initWindow(Display* display);
diff --git a/tools/sk_app/win/ANGLEWindowContext_win.cpp b/tools/sk_app/win/ANGLEWindowContext_win.cpp
index 649528d6cd..452b462ba9 100644
--- a/tools/sk_app/win/ANGLEWindowContext_win.cpp
+++ b/tools/sk_app/win/ANGLEWindowContext_win.cpp
@@ -76,7 +76,8 @@ sk_sp<const GrGLInterface> ANGLEGLWindowContext_win::onInitializeContext() {
     }
     EGLint numConfigs;
     fSampleCount = this->getDisplayParams().fMSAASampleCount;
-    const int sampleBuffers = fSampleCount > 0 ? 1 : 0;
+    const int sampleBuffers = fSampleCount > 1 ? 1 : 0;
+    const int eglSampleCnt = fSampleCount > 1 ? fSampleCount : 0;
     const EGLint configAttribs[] = {EGL_RENDERABLE_TYPE,
                                     // We currently only support ES3.
                                     EGL_OPENGL_ES3_BIT,
@@ -91,7 +92,7 @@ sk_sp<const GrGLInterface> ANGLEGLWindowContext_win::onInitializeContext() {
                                     EGL_SAMPLE_BUFFERS,
                                     sampleBuffers,
                                     EGL_SAMPLES,
-                                    fSampleCount,
+                                    eglSampleCnt,
                                     EGL_NONE};
 
     EGLConfig surfaceConfig;
diff --git a/tools/sk_app/win/GLWindowContext_win.cpp b/tools/sk_app/win/GLWindowContext_win.cpp
index 7e43d2b544..1c583cb1ed 100644
--- a/tools/sk_app/win/GLWindowContext_win.cpp
+++ b/tools/sk_app/win/GLWindowContext_win.cpp
@@ -96,8 +96,9 @@ sk_sp<const GrGLInterface> GLWindowContext_win::onInitializeContext() {
                                               1,
                                               &kSampleCountAttr,
                                               &fSampleCount);
+            fSampleCount = SkTMax(fSampleCount, 1);
         } else {
-            fSampleCount = 0;
+            fSampleCount = 1;
         }
 
         RECT rect;
diff --git a/tools/skpbench/skpbench.cpp b/tools/skpbench/skpbench.cpp
index fcab2d3af8..6b89bc27ff 100644
--- a/tools/skpbench/skpbench.cpp
+++ b/tools/skpbench/skpbench.cpp
@@ -292,7 +292,8 @@ int main(int argc, char** argv) {
     GrPixelConfig grPixConfig = SkImageInfo2GrPixelConfig(config->getColorType(),
                                                           config->getColorSpace(),
                                                           *ctx->caps());
-    int supportedSampleCount = ctx->caps()->getSampleCount(config->getSamples(), grPixConfig);
+    int supportedSampleCount =
+            ctx->caps()->getRenderTargetSampleCount(config->getSamples(), grPixConfig);
     if (supportedSampleCount != config->getSamples()) {
         exitf(ExitErr::kUnavailable, "sample count %i not supported by platform",
                                      config->getSamples());
diff --git a/tools/viewer/Viewer.cpp b/tools/viewer/Viewer.cpp
index 198f9baab6..35b0e146f9 100644
--- a/tools/viewer/Viewer.cpp
+++ b/tools/viewer/Viewer.cpp
@@ -78,7 +78,7 @@ static DEFINE_string(jsons, "jsons", "Directory to read (Bodymovin) jsons from."
 
 static DEFINE_string2(backend, b, "sw", "Backend to use. Allowed values are " BACKENDS_STR ".");
 
-static DEFINE_int32(msaa, 0, "Number of subpixel samples. 0 for no HW antialiasing.");
+static DEFINE_int32(msaa, 1, "Number of subpixel samples. 0 for no HW antialiasing.");
 
 DECLARE_int32(threads)
 
@@ -501,7 +501,7 @@ void Viewer::updateTitle() {
     if (!fWindow) {
         return;
     }
-    if (fWindow->sampleCount() < 0) {
+    if (fWindow->sampleCount() < 1) {
         return; // Surface hasn't been created yet.
     }
 
@@ -561,7 +561,8 @@ void Viewer::updateTitle() {
 
     title.append(" [");
     title.append(kBackendTypeStrings[fBackendType]);
-    if (int msaa = fWindow->sampleCount()) {
+    int msaa = fWindow->sampleCount();
+    if (msaa > 1) {
         title.appendf(" MSAA: %i", msaa);
     }
     title.append("]");
@@ -994,7 +995,7 @@ void Viewer::drawImGui() {
                 if (ctx) {
                     int sampleCount = fWindow->sampleCount();
                     ImGui::Text("MSAA: "); ImGui::SameLine();
-                    ImGui::RadioButton("0", &sampleCount, 0); ImGui::SameLine();
+                    ImGui::RadioButton("1", &sampleCount, 1); ImGui::SameLine();
                     ImGui::RadioButton("4", &sampleCount, 4); ImGui::SameLine();
                     ImGui::RadioButton("8", &sampleCount, 8); ImGui::SameLine();
                     ImGui::RadioButton("16", &sampleCount, 16);
@@ -1018,7 +1019,7 @@ void Viewer::drawImGui() {
 
                     if (!ctx) {
                         ImGui::RadioButton("Software", true);
-                    } else if (fWindow->sampleCount()) {
+                    } else if (fWindow->sampleCount() > 1) {
                         prButton(GpuPathRenderers::kDefault);
                         prButton(GpuPathRenderers::kAll);
                         if (ctx->caps()->shaderCaps()->pathRenderingSupport()) {
@@ -1198,7 +1199,7 @@ void Viewer::updateUIState() {
     if (!fWindow) {
         return;
     }
-    if (fWindow->sampleCount() < 0) {
+    if (fWindow->sampleCount() < 1) {
         return; // Surface hasn't been created yet.
     }
 
@@ -1244,7 +1245,7 @@ void Viewer::updateUIState() {
     const GrContext* ctx = fWindow->getGrContext();
     if (!ctx) {
         prState[kOptions].append("Software");
-    } else if (fWindow->sampleCount()) {
+    } else if (fWindow->sampleCount() > 1) {
         prState[kOptions].append(gPathRendererNames[GpuPathRenderers::kDefault]);
         prState[kOptions].append(gPathRendererNames[GpuPathRenderers::kAll]);
         if (ctx->caps()->shaderCaps()->pathRenderingSupport()) {