Implement path cover with nv_path_rendering

src/gpu/gl/GrGpuGL.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 
 #include "GrGpuGL.h"
 #include "GrGLStencilBuffer.h"
@@ skipping 338 matching lines @@
     if (resetBits & kView_GrGLBackendState) {
         fHWScissorSettings.invalidate();
         fHWViewport.invalidate();
     }
 
     if (resetBits & kStencil_GrGLBackendState) {
         fHWStencilSettings.invalidate();
         fHWStencilTestEnabled = kUnknown_TriState;
     }
 
+    if (resetBits & kPathRendering_GrGLBackendState && this->glCaps().pathRenderingSupport()) {
+        fHWPathStencilSettings.invalidate();

[Chris Dalton, 2013/10/07 22:22:45]

It's a little confusing that kPathRendering_GrGLBackendState doesn't reset
PathTexGen.

Eventually we'll probably want to maintain PathTexGen and TexGen separately, and
maybe pass a DrawType to enableTexGen(). That way we can just reset PathTexGen
here instead of in the fixed function block.

[Kimmo Kinnunen, 2013/10/08 12:14:09]

Done.

+    }
+
     // Vertex
     if (resetBits & kVertex_GrGLBackendState) {
         fHWGeometryState.invalidate();
     }
 
     if (resetBits & kRenderTarget_GrGLBackendState) {
         fHWBoundRenderTarget = NULL;
     }
 
     if (resetBits & kFixedFunction_GrGLBackendState && this->glCaps().fixedFunctionSupport()) {

[Chris Dalton, 2013/10/07 22:22:45]

Maybe for now we can just mix path rendering and fixed function into the same
block?

(It's impossible to have path rendering without fixed function)

 
         fHWProjectionMatrixState.invalidate();
         // we don't use the model view matrix.
         GL_CALL(MatrixMode(GR_GL_MODELVIEW));
         GL_CALL(LoadIdentity());
 
         for (int i = 0; i < this->glCaps().maxFixedFunctionTextureCoords(); ++i) {
             GL_CALL(ActiveTexture(GR_GL_TEXTURE0 + i));
             GL_CALL(Disable(GR_GL_TEXTURE_GEN_S));
             GL_CALL(Disable(GR_GL_TEXTURE_GEN_T));
             GL_CALL(Disable(GR_GL_TEXTURE_GEN_Q));
             GL_CALL(Disable(GR_GL_TEXTURE_GEN_R));
-            if (this->caps()->pathStencilingSupport()) {
+            if (this->caps()->pathRenderingSupport()) {
                 GL_CALL(PathTexGen(GR_GL_TEXTURE0 + i, GR_GL_NONE, 0, NULL));
             }
             fHWTexGenSettings[i].fMode = GR_GL_NONE;
             fHWTexGenSettings[i].fNumComponents = 0;
         }
         fHWActiveTexGenSets = 0;
     }
 
     // we assume these values
     if (resetBits & kPixelStore_GrGLBackendState) {
@@ skipping 874 matching lines @@
                 return NULL;
             }
             GrIndexBuffer* indexBuffer = SkNEW_ARGS(GrGLIndexBuffer, (this, desc));
             return indexBuffer;
         }
         return NULL;
     }
 }
 
 GrPath* GrGpuGL::onCreatePath(const SkPath& inPath) {
-    SkASSERT(this->caps()->pathStencilingSupport());
+    SkASSERT(this->caps()->pathRenderingSupport());
     return SkNEW_ARGS(GrGLPath, (this, inPath));
 }
 
 void GrGpuGL::flushScissor() {
     if (fScissorState.fEnabled) {
         // Only access the RT if scissoring is being enabled. We can call this before performing
         // a glBitframebuffer for a surface->surface copy, which requires no RT to be bound to the
         // GrDrawState.
         const GrDrawState& drawState = this->getDrawState();
         const GrGLRenderTarget* rt =
@@ skipping 373 matching lines @@
         aglSwapBuffers(aglGetCurrentContext());
     #elif defined(SK_BUILD_FOR_WIN32)
         SwapBuf();
         int set_a_break_pt_here = 9;
         SwapBuf();
     #endif
 #endif
 }
 
 namespace {
-
-static const uint16_t kOnes16 = static_cast<uint16_t>(~0);
-const GrStencilSettings& winding_nv_path_stencil_settings() {
-    GR_STATIC_CONST_SAME_STENCIL_STRUCT(gSettings,
-        kIncClamp_StencilOp,
-        kIncClamp_StencilOp,
-        kAlwaysIfInClip_StencilFunc,
-        kOnes16, kOnes16, kOnes16);
-    return *GR_CONST_STENCIL_SETTINGS_PTR_FROM_STRUCT_PTR(&gSettings);
-}
-const GrStencilSettings& even_odd_nv_path_stencil_settings() {
-    GR_STATIC_CONST_SAME_STENCIL_STRUCT(gSettings,
-        kInvert_StencilOp,
-        kInvert_StencilOp,
-        kAlwaysIfInClip_StencilFunc,
-        kOnes16, kOnes16, kOnes16);
-    return *GR_CONST_STENCIL_SETTINGS_PTR_FROM_STRUCT_PTR(&gSettings);
+GrGLenum gr_stencil_op_to_gl_path_rendering_fill_mode(GrStencilOp op) {
+    switch (op) {
+        default:
+            GrCrash("Unexpected path fill.");
+            /* fallthrough */;
+        case kIncClamp_StencilOp:
+            return GR_GL_COUNT_UP;
+        case kInvert_StencilOp:
+            return GR_GL_INVERT;
+    }
 }
 }
 
-void GrGpuGL::setStencilPathSettings(const GrPath&,
-                                     SkPath::FillType fill,
-                                     GrStencilSettings* settings) {
-    switch (fill) {
-        case SkPath::kEvenOdd_FillType:
-            *settings = even_odd_nv_path_stencil_settings();
-            return;
-        case SkPath::kWinding_FillType:
-            *settings = winding_nv_path_stencil_settings();
-            return;
-        default:
-            GrCrash("Unexpected path fill.");
+void GrGpuGL::onGpuStencilPath(const GrPath* path, SkPath::FillType fill) {
+    SkASSERT(this->caps()->pathRenderingSupport());
+
+    GrGLuint id = static_cast<const GrGLPath*>(path)->pathID();
+    SkASSERT(NULL != this->drawState()->getRenderTarget());
+    SkASSERT(NULL != this->drawState()->getRenderTarget()->getStencilBuffer());
+
+    flushPathStencilSettings(fill);
+
+    // Decide how to manipulate the stencil buffer based on the fill rule.
+    SkASSERT(!fHWPathStencilSettings.isTwoSided());
+
+    GrGLenum fillMode =
+        gr_stencil_op_to_gl_path_rendering_fill_mode(fHWPathStencilSettings.passOp(GrStencilSettings::kFront_Face));
+    GrGLint writeMask = fHWPathStencilSettings.writeMask(GrStencilSettings::kFront_Face);
+    GL_CALL(StencilFillPath(id, fillMode, writeMask));
+}
+
+void GrGpuGL::onGpuFillPath(const GrPath* path, SkPath::FillType fill) {
+    SkASSERT(this->caps()->pathRenderingSupport());
+
+    GrGLuint id = static_cast<const GrGLPath*>(path)->pathID();
+    SkASSERT(NULL != this->drawState()->getRenderTarget());
+    SkASSERT(NULL != this->drawState()->getRenderTarget()->getStencilBuffer());
+    SkASSERT(!fCurrentProgram->hasVertexShader());
+
+    flushPathStencilSettings(fill);
+
+    SkPath::FillType nonInvertedFill = SkPath::ConvertToNonInverseFillType(fill);
+    SkASSERT(!fHWPathStencilSettings.isTwoSided());
+    GrGLenum fillMode =
+        gr_stencil_op_to_gl_path_rendering_fill_mode(fHWPathStencilSettings.passOp(GrStencilSettings::kFront_Face));
+    GrGLint writeMask = fHWPathStencilSettings.writeMask(GrStencilSettings::kFront_Face);
+    GL_CALL(StencilFillPath(id, fillMode, writeMask));
+
+    if (nonInvertedFill == fill) {
+        GL_CALL(CoverFillPath(id, GR_GL_BOUNDING_BOX));
+    } else {
+        GrDrawState* drawState = this->drawState();
+        GrDrawState::AutoViewMatrixRestore avmr;
+        SkRect bounds = SkRect::MakeLTRB(0, 0,
+                                         SkIntToScalar(drawState->getRenderTarget()->width()),
+                                         SkIntToScalar(drawState->getRenderTarget()->height()));
+        SkMatrix vmi;
+        // mapRect through persp matrix may not be correct
+        if (!drawState->getViewMatrix().hasPerspective() && drawState->getViewInverse(&vmi)) {
+            vmi.mapRect(&bounds);
+            // theoretically could set bloat = 0, instead leave it because of matrix inversion
+            // precision.
+            SkScalar bloat = drawState->getViewMatrix().getMaxStretch() * SK_ScalarHalf;
+            bounds.outset(bloat, bloat);
+        } else {
+            avmr.setIdentity(drawState);
+        }
+
+        this->drawSimpleRect(bounds, NULL);
     }
 }
 
-void GrGpuGL::onGpuStencilPath(const GrPath* path, SkPath::FillType fill) {
-    SkASSERT(this->caps()->pathStencilingSupport());
-
-    GrGLuint id = static_cast<const GrGLPath*>(path)->pathID();
-    GrDrawState* drawState = this->drawState();
-    SkASSERT(NULL != drawState->getRenderTarget());
-    if (NULL == drawState->getRenderTarget()->getStencilBuffer()) {
-        return;
-    }
-
-    // Decide how to manipulate the stencil buffer based on the fill rule.
-    // Also, assert that the stencil settings we set in setStencilPathSettings
-    // are present.
-    SkASSERT(!fStencilSettings.isTwoSided());
-    GrGLenum fillMode;
-    switch (fill) {
-        case SkPath::kWinding_FillType:
-            fillMode = GR_GL_COUNT_UP;
-            SkASSERT(kIncClamp_StencilOp ==
-                     fStencilSettings.passOp(GrStencilSettings::kFront_Face));
-            SkASSERT(kIncClamp_StencilOp ==
-                     fStencilSettings.failOp(GrStencilSettings::kFront_Face));
-            break;
-        case SkPath::kEvenOdd_FillType:
-            fillMode = GR_GL_INVERT;
-            SkASSERT(kInvert_StencilOp ==
-                     fStencilSettings.passOp(GrStencilSettings::kFront_Face));
-            SkASSERT(kInvert_StencilOp ==
-                fStencilSettings.failOp(GrStencilSettings::kFront_Face));
-            break;
-        default:
-            // Only the above two fill rules are allowed.
-            GrCrash("Unexpected path fill.");
-            return; // suppress unused var warning.
-    }
-    GrGLint writeMask = fStencilSettings.writeMask(GrStencilSettings::kFront_Face);
-    GL_CALL(StencilFillPath(id, fillMode, writeMask));
-}
-
 void GrGpuGL::onResolveRenderTarget(GrRenderTarget* target) {
     GrGLRenderTarget* rt = static_cast<GrGLRenderTarget*>(target);
     if (rt->needsResolve()) {
         // Some extensions automatically resolves the texture when it is read.
         if (this->glCaps().usesMSAARenderBuffers()) {
             SkASSERT(rt->textureFBOID() != rt->renderFBOID());
             GL_CALL(BindFramebuffer(GR_GL_READ_FRAMEBUFFER, rt->renderFBOID()));
             GL_CALL(BindFramebuffer(GR_GL_DRAW_FRAMEBUFFER, rt->textureFBOID()));
             // make sure we go through flushRenderTarget() since we've modified
             // the bound DRAW FBO ID.
@@ skipping 101 matching lines @@
         GR_GL_CALL(gl, StencilOp(glFailOp, glPassOp, glPassOp));
     } else {
         GR_GL_CALL(gl, StencilFuncSeparate(glFace, glFunc, ref, mask));
         GR_GL_CALL(gl, StencilMaskSeparate(glFace, writeMask));
         GR_GL_CALL(gl, StencilOpSeparate(glFace, glFailOp, glPassOp, glPassOp));
     }
 }
 }
 
 void GrGpuGL::flushStencil(DrawType type) {
-    if (kStencilPath_DrawType == type) {
-        SkASSERT(!fStencilSettings.isTwoSided());
-        // Just the func, ref, and mask is set here. The op and write mask are params to the call
-        // that draws the path to the SB (glStencilFillPath)
-        GrGLenum func =
-            gr_to_gl_stencil_func(fStencilSettings.func(GrStencilSettings::kFront_Face));
-        GL_CALL(PathStencilFunc(func,
-                                fStencilSettings.funcRef(GrStencilSettings::kFront_Face),
-                                fStencilSettings.funcMask(GrStencilSettings::kFront_Face)));
-    } else if (fHWStencilSettings != fStencilSettings) {
+    if (kStencilPath_DrawType != type && fHWStencilSettings != fStencilSettings) {
         if (fStencilSettings.isDisabled()) {
             if (kNo_TriState != fHWStencilTestEnabled) {
                 GL_CALL(Disable(GR_GL_STENCIL_TEST));
                 fHWStencilTestEnabled = kNo_TriState;
             }
         } else {
             if (kYes_TriState != fHWStencilTestEnabled) {
                 GL_CALL(Enable(GR_GL_STENCIL_TEST));
                 fHWStencilTestEnabled = kYes_TriState;
             }
@@ skipping 69 matching lines @@
             } else {
                 if (kNo_TriState != fHWAAState.fMSAAEnabled) {
                     GL_CALL(Disable(GR_GL_MULTISAMPLE));
                     fHWAAState.fMSAAEnabled = kNo_TriState;
                 }
             }
         }
     }
 }
 
+void GrGpuGL::flushPathStencilSettings(SkPath::FillType fill) {
+    GrStencilSettings pathStencilSettings;
+    this->getPathStencilSettingsForFillType(fill, &pathStencilSettings);
+    if (fHWPathStencilSettings != pathStencilSettings) {
+        // Just the func, ref, and mask is set here. The op and write mask are params to the call
+        // that draws the path to the SB (glStencilFillPath)
+        GrGLenum func =
+            gr_to_gl_stencil_func(pathStencilSettings.func(GrStencilSettings::kFront_Face));
+        GL_CALL(PathStencilFunc(func,
+                                pathStencilSettings.funcRef(GrStencilSettings::kFront_Face),
+                                pathStencilSettings.funcMask(GrStencilSettings::kFront_Face)));
+
+        fHWPathStencilSettings = pathStencilSettings;
+    }
+}
+
 void GrGpuGL::flushBlend(bool isLines,
                          GrBlendCoeff srcCoeff,
                          GrBlendCoeff dstCoeff) {
     if (isLines && this->willUseHWAALines()) {
         if (kYes_TriState != fHWBlendState.fEnabled) {
             GL_CALL(Enable(GR_GL_BLEND));
             fHWBlendState.fEnabled = kYes_TriState;
         }
         if (kSA_GrBlendCoeff != fHWBlendState.fSrcCoeff ||
             kISA_GrBlendCoeff != fHWBlendState.fDstCoeff) {
@@ skipping 167 matching lines @@
     fHWProjectionMatrixState.getGLMatrix<4>(glMatrix);
     GL_CALL(MatrixMode(GR_GL_PROJECTION));
     GL_CALL(LoadMatrixf(glMatrix));
 }
 
 void GrGpuGL::enableTexGen(int unitIdx,
                            TexGenComponents components,
                            const GrGLfloat* coefficients) {
 
     SkASSERT(this->glCaps().fixedFunctionSupport());
-    SkASSERT(this->caps()->pathStencilingSupport());
+    SkASSERT(this->caps()->pathRenderingSupport());
     SkASSERT(components >= kS_TexGenComponents && components <= kSTR_TexGenComponents);
 
     if (GR_GL_OBJECT_LINEAR == fHWTexGenSettings[unitIdx].fMode &&
         components == fHWTexGenSettings[unitIdx].fNumComponents &&
         !memcmp(coefficients, fHWTexGenSettings[unitIdx].fCoefficients,
                 3 * components * sizeof(GrGLfloat))) {
         return;
     }
 
     this->setTextureUnit(unitIdx);
@@ skipping 553 matching lines @@
             this->setVertexArrayID(gpu, 0);
         }
         int attrCount = gpu->glCaps().maxVertexAttributes();
         if (fDefaultVertexArrayAttribState.count() != attrCount) {
             fDefaultVertexArrayAttribState.resize(attrCount);
         }
         attribState = &fDefaultVertexArrayAttribState;
     }
     return attribState;
 }