Add clamp to border wrap mode to gpu

Bug: skia:
Change-Id: I286163cdea4fa8f7e6a876baaa11aa3dacd4f2ff
Reviewed-on: https://skia-review.googlesource.com/c/175244
Reviewed-by: Brian Salomon <bsalomon@google.com>
Reviewed-by: Greg Daniel <egdaniel@google.com>
Commit-Queue: Michael Ludwig <michaelludwig@google.com>

Author: lhkbob

include/gpu/GrSamplerState.h

@@ -16,7 +16,7 @@
 class GrSamplerState {
 public:
     enum class Filter : uint8_t { kNearest, kBilerp, kMipMap };
-    enum class WrapMode : uint8_t { kClamp, kRepeat, kMirrorRepeat };
+    enum class WrapMode : uint8_t { kClamp, kRepeat, kMirrorRepeat, kClampToBorder };
 
     static constexpr GrSamplerState ClampNearest() { return GrSamplerState(); }
     static constexpr GrSamplerState ClampBilerp() {
@@ -51,7 +51,8 @@ class GrSamplerState {
     WrapMode wrapModeY() const { return fWrapModes[1]; }
 
     bool isRepeated() const {
-        return WrapMode::kClamp != fWrapModes[0] || WrapMode::kClamp != fWrapModes[1];
+        return (WrapMode::kClamp != fWrapModes[0] && WrapMode::kClampToBorder != fWrapModes[0]) ||
+               (WrapMode::kClamp != fWrapModes[1] && WrapMode::kClampToBorder != fWrapModes[1]);
     }
 
     bool operator==(const GrSamplerState& that) const {

src/gpu/GrCaps.cpp

@@ -72,6 +72,9 @@ GrCaps::GrCaps(const GrContextOptions& options) {
 
     fPreferVRAMUseOverFlushes = true;
 
+    // Default to true, allow older versions of OpenGL to disable explicitly
+    fClampToBorderSupport = true;
+
     fDriverBugWorkarounds = options.fDriverBugWorkarounds;
 }
 

src/gpu/GrCaps.h

@@ -311,6 +311,12 @@ class GrCaps : public SkRefCnt {
      */
     GrBackendFormat createFormatFromBackendTexture(const GrBackendTexture&) const;
 
+    /**
+     * The CLAMP_TO_BORDER wrap mode for texture coordinates was added to desktop GL in 1.3, and
+     * GLES 3.2, but is also available in extensions. Vulkan and Metal always have support.
+     */
+    bool clampToBorderSupport() const { return fClampToBorderSupport; }
+
     const GrDriverBugWorkarounds& workarounds() const { return fDriverBugWorkarounds; }
 
 protected:
@@ -347,6 +353,7 @@ class GrCaps : public SkRefCnt {
     bool fMustClearUploadedBufferData                : 1;
     bool fSupportsAHardwareBufferImages              : 1;
     bool fHalfFloatVertexAttributeSupport            : 1;
+    bool fClampToBorderSupport                       : 1;
 
     // Driver workaround
     bool fBlacklistCoverageCounting                  : 1;

src/gpu/gl/GrGLCaps.cpp

@@ -235,6 +235,21 @@ void GrGLCaps::init(const GrContextOptions& contextOptions,
         // lacks TexImage2D support and ANGLE lacks GL ES 3.0 support.
     }
 
+    // GrCaps defaults fClampToBorderSupport to true, so disable when unsupported
+    if (kGL_GrGLStandard == standard) {
+        // Clamp to border added in 1.3
+        if (version < GR_GL_VER(1, 3) && !ctxInfo.hasExtension("GL_ARB_texture_border_clamp")) {
+            fClampToBorderSupport = false;
+        }
+    } else if (kGLES_GrGLStandard == standard) {
+        // GLES didn't have clamp to border until 3.2, but provides several alternative extensions
+        if (version < GR_GL_VER(3, 2) && !ctxInfo.hasExtension("GL_EXT_texture_border_clamp") &&
+            !ctxInfo.hasExtension("GL_NV_texture_border_clamp") &&
+            !ctxInfo.hasExtension("GL_OES_texture_border_clamp")) {
+            fClampToBorderSupport = false;
+        }
+    }
+
     if (kGL_GrGLStandard == standard) {
         if (version >= GR_GL_VER(3,3) || ctxInfo.hasExtension("GL_ARB_texture_swizzle")) {
             fTextureSwizzleSupport = true;

src/gpu/gl/GrGLDefines.h

@@ -670,6 +670,7 @@
 #define GR_GL_REPEAT                         0x2901
 #define GR_GL_CLAMP_TO_EDGE                  0x812F
 #define GR_GL_MIRRORED_REPEAT                0x8370
+#define GR_GL_CLAMP_TO_BORDER                0x812D
 
 /* Texture Swizzle */
 #define GR_GL_TEXTURE_SWIZZLE_R              0x8E42

src/gpu/gl/GrGLGpu.cpp

@@ -202,11 +202,16 @@ static GrGLenum filter_to_gl_min_filter(GrSamplerState::Filter filter) {
     return 0;
 }
 
-static inline GrGLenum wrap_mode_to_gl_wrap(GrSamplerState::WrapMode wrapMode) {
+static inline GrGLenum wrap_mode_to_gl_wrap(GrSamplerState::WrapMode wrapMode,
+                                            const GrCaps& caps) {
     switch (wrapMode) {
         case GrSamplerState::WrapMode::kClamp:        return GR_GL_CLAMP_TO_EDGE;
         case GrSamplerState::WrapMode::kRepeat:       return GR_GL_REPEAT;
         case GrSamplerState::WrapMode::kMirrorRepeat: return GR_GL_MIRRORED_REPEAT;
+        case GrSamplerState::WrapMode::kClampToBorder:
+            // May not be supported but should have been caught earlier
+            SkASSERT(caps.clampToBorderSupport());
+            return GR_GL_CLAMP_TO_BORDER;
     }
     SK_ABORT("Unknown wrap mode");
     return 0;
@@ -242,8 +247,8 @@ class GrGLGpu::SamplerObjectCache {
             fSamplers[index] = s;
             auto minFilter = filter_to_gl_min_filter(state.filter());
             auto magFilter = filter_to_gl_mag_filter(state.filter());
-            auto wrapX = wrap_mode_to_gl_wrap(state.wrapModeX());
-            auto wrapY = wrap_mode_to_gl_wrap(state.wrapModeY());
+            auto wrapX = wrap_mode_to_gl_wrap(state.wrapModeX(), fGpu->glCaps());
+            auto wrapY = wrap_mode_to_gl_wrap(state.wrapModeY(), fGpu->glCaps());
             GR_GL_CALL(fGpu->glInterface(),
                        SamplerParameteri(s, GR_GL_TEXTURE_MIN_FILTER, minFilter));
             GR_GL_CALL(fGpu->glInterface(),
@@ -284,16 +289,16 @@ class GrGLGpu::SamplerObjectCache {
         int filter = static_cast<int>(state.filter());
         SkASSERT(filter >= 0 && filter < 3);
         int wrapX = static_cast<int>(state.wrapModeX());
-        SkASSERT(wrapX >= 0 && wrapX < 3);
+        SkASSERT(wrapX >= 0 && wrapX < 4);
         int wrapY = static_cast<int>(state.wrapModeY());
-        SkASSERT(wrapY >= 0 && wrapY < 3);
-        int idx = 9 * filter + 3 * wrapX + wrapY;
+        SkASSERT(wrapY >= 0 && wrapY < 4);
+        int idx = 16 * filter + 4 * wrapX + wrapY;
         SkASSERT(idx < kNumSamplers);
         return idx;
     }
 
     GrGLGpu* fGpu;
-    static constexpr int kNumSamplers = 27;
+    static constexpr int kNumSamplers = 48;
     std::unique_ptr<GrGLuint[]> fHWBoundSamplers;
     GrGLuint fSamplers[kNumSamplers];
     int fNumTextureUnits;
@@ -2854,8 +2859,8 @@ void GrGLGpu::bindTexture(int unitIdx, GrSamplerState samplerState, GrGLTexture*
         newSamplerParams.fMinFilter = filter_to_gl_min_filter(samplerState.filter());
         newSamplerParams.fMagFilter = filter_to_gl_mag_filter(samplerState.filter());
 
-        newSamplerParams.fWrapS = wrap_mode_to_gl_wrap(samplerState.wrapModeX());
-        newSamplerParams.fWrapT = wrap_mode_to_gl_wrap(samplerState.wrapModeY());
+        newSamplerParams.fWrapS = wrap_mode_to_gl_wrap(samplerState.wrapModeX(), this->glCaps());
+        newSamplerParams.fWrapT = wrap_mode_to_gl_wrap(samplerState.wrapModeY(), this->glCaps());
 
         // These are the OpenGL default values.
         newSamplerParams.fMinLOD = -1000;
@@ -2889,6 +2894,17 @@ void GrGLGpu::bindTexture(int unitIdx, GrSamplerState samplerState, GrGLTexture*
             this->setTextureUnit(unitIdx);
             GL_CALL(TexParameteri(target, GR_GL_TEXTURE_WRAP_T, newSamplerParams.fWrapT));
         }
+        if (this->glCaps().clampToBorderSupport()) {
+            // Make sure the border color is transparent black (the default)
+            if (setAll || oldSamplerParams.fBorderColorInvalid) {
+                this->setTextureUnit(unitIdx);
+                // Specify the transparent black as normalized signed integers. The conversion is
+                // defined as (2c+1)/(2^32-1), which makes it impossible to map a signed in to
+                // exactly 0.f.  But 1/(2^32-1) is close enough.
+                static const GrGLint kTransparentBlack[4] = {0, 0, 0, 0};
+                GL_CALL(TexParameteriv(target, GR_GL_TEXTURE_BORDER_COLOR, kTransparentBlack));
+            }
+        }
     }
     GrGLTexture::NonSamplerParams newNonSamplerParams;
     newNonSamplerParams.fBaseMipMapLevel = 0;

src/gpu/gl/GrGLTexture.h

@@ -27,13 +27,18 @@ class GrGLTexture : public GrTexture {
         GrGLenum fWrapT = GR_GL_REPEAT;
         GrGLfloat fMinLOD = -1000.f;
         GrGLfloat fMaxLOD = 1000.f;
+        // We always want the border color to be transparent black, so no need to store 4 floats.
+        // Just track if it's been invalidated and no longer the default
+        bool fBorderColorInvalid = false;
+
         void invalidate() {
             fMinFilter = ~0U;
             fMagFilter = ~0U;
             fWrapS = ~0U;
             fWrapT = ~0U;
             fMinLOD = SK_ScalarNaN;
             fMaxLOD = SK_ScalarNaN;
+            fBorderColorInvalid = true;
         }
     };
 

src/gpu/mtl/GrMtlSampler.mm

@@ -18,6 +18,8 @@ static inline MTLSamplerAddressMode wrap_mode_to_mtl_sampler_address(
             return MTLSamplerAddressModeRepeat;
         case GrSamplerState::WrapMode::kMirrorRepeat:
             return MTLSamplerAddressModeMirrorRepeat;
+        case GrSamplerState::WrapMode::kClampToBorder:
+            return MTLSamplerAddressModeClampToBorderColor;
     }
     SK_ABORT("Unknown wrap mode.");
     return MTLSamplerAddressModeClampToEdge;

src/gpu/vk/GrVkSampler.cpp

@@ -19,6 +19,8 @@ static inline VkSamplerAddressMode wrap_mode_to_vk_sampler_address(
             return VK_SAMPLER_ADDRESS_MODE_REPEAT;
         case GrSamplerState::WrapMode::kMirrorRepeat:
             return VK_SAMPLER_ADDRESS_MODE_MIRRORED_REPEAT;
+        case GrSamplerState::WrapMode::kClampToBorder:
+            return VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_BORDER;
     }
     SK_ABORT("Unknown wrap mode.");
     return VK_SAMPLER_ADDRESS_MODE_CLAMP_TO_EDGE;

src/shaders/SkImageShader.cpp

@@ -171,8 +171,7 @@ static GrSamplerState::WrapMode tile_mode_to_wrap_mode(const SkShader::TileMode
         case SkShader::TileMode::kMirror_TileMode:
             return GrSamplerState::WrapMode::kMirrorRepeat;
         case SkShader::kDecal_TileMode:
-            // TODO: depending on caps, we should extend WrapMode for decal...
-            return GrSamplerState::WrapMode::kClamp;
+            return GrSamplerState::WrapMode::kClampToBorder;
     }
     SK_ABORT("Unknown tile mode.");
     return GrSamplerState::WrapMode::kClamp;
@@ -188,6 +187,19 @@ std::unique_ptr<GrFragmentProcessor> SkImageShader::asFragmentProcessor(
 
     GrSamplerState::WrapMode wrapModes[] = {tile_mode_to_wrap_mode(fTileModeX),
                                             tile_mode_to_wrap_mode(fTileModeY)};
+    if ((wrapModes[0] == GrSamplerState::WrapMode::kClampToBorder ||
+         wrapModes[1] == GrSamplerState::WrapMode::kClampToBorder) &&
+        !args.fContext->contextPriv().caps()->clampToBorderSupport()) {
+        // HW clamp to border is unavailable, so fall back to clamp for now
+        // TODO(michaelludwig): If clamp-to-border is selected but is unsupported, the texture
+        // domain effect could be used to emulate the decal effect.
+        if (wrapModes[0] == GrSamplerState::WrapMode::kClampToBorder) {
+            wrapModes[0] = GrSamplerState::WrapMode::kClamp;
+        }
+        if (wrapModes[1] == GrSamplerState::WrapMode::kClampToBorder) {
+            wrapModes[1] = GrSamplerState::WrapMode::kClamp;
+        }
+    }
 
     // Must set wrap and filter on the sampler before requesting a texture. In two places below
     // we check the matrix scale factors to determine how to interpret the filter quality setting.