hide most details of SkPatchUtils

relies on https://googleplex-android-review.git.corp.google.com/#/c/2060523/ landing first

Bug: skia:
Change-Id: Ic6dc8e53656a7190a32cfb3b0b2abd9ee6dbebf0
Reviewed-on: https://skia-review.googlesource.com/11351
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Reed <reed@google.com>

4 files changed, 54 insertions, 244 deletions

diff --git a/src/core/SkDevice.cpp b/src/core/SkDevice.cpp
index 21287a2260..f2732e2569 100644
--- a/src/core/SkDevice.cpp
+++ b/src/core/SkDevice.cpp
@@ -126,8 +126,6 @@ void SkBaseDevice::drawDRRect(const SkRRect& outer,
 
 void SkBaseDevice::drawPatch(const SkPoint cubics[12], const SkColor colors[4],
                              const SkPoint texCoords[4], SkBlendMode bmode, const SkPaint& paint) {
-    SkPatchUtils::VertexData data;
-
     SkISize lod = SkPatchUtils::GetLevelOfDetail(cubics, &this->ctm());
     auto vertices = SkPatchUtils::MakeVertices(cubics, colors, texCoords, lod.width(), lod.height());
     if (vertices) {
diff --git a/src/utils/SkDumpCanvas.cpp b/src/utils/SkDumpCanvas.cpp
index 8e1f554998..35b88de595 100644
--- a/src/utils/SkDumpCanvas.cpp
+++ b/src/utils/SkDumpCanvas.cpp
@@ -478,14 +478,10 @@ void SkDumpCanvas::onDrawPatch(const SkPoint cubics[12], const SkColor colors[4]
     this->dump(kDrawPatch_Verb, &paint, "drawPatch(Vertices{[%f, %f], [%f, %f], [%f, %f], [%f, %f]}\
               | Colors{[0x%x], [0x%x], [0x%x], [0x%x]} | TexCoords{[%f,%f], [%f,%f], [%f,%f], \
                [%f,%f]})",
-              cubics[SkPatchUtils::kTopP0_CubicCtrlPts].fX,
-              cubics[SkPatchUtils::kTopP0_CubicCtrlPts].fY,
-              cubics[SkPatchUtils::kTopP3_CubicCtrlPts].fX,
-              cubics[SkPatchUtils::kTopP3_CubicCtrlPts].fY,
-              cubics[SkPatchUtils::kBottomP3_CubicCtrlPts].fX,
-              cubics[SkPatchUtils::kBottomP3_CubicCtrlPts].fY,
-              cubics[SkPatchUtils::kBottomP0_CubicCtrlPts].fX,
-              cubics[SkPatchUtils::kBottomP0_CubicCtrlPts].fY,
+              cubics[0].fX, cubics[0].fY,
+              cubics[3].fX, cubics[3].fY,
+              cubics[6].fX, cubics[6].fY,
+              cubics[9].fX, cubics[9].fY,
               colors[0], colors[1], colors[2], colors[3],
               texCoords[0].x(), texCoords[0].y(), texCoords[1].x(), texCoords[1].y(),
               texCoords[2].x(), texCoords[2].y(), texCoords[3].x(), texCoords[3].y());
diff --git a/src/utils/SkPatchUtils.cpp b/src/utils/SkPatchUtils.cpp
index 7567304835..9a789ea80f 100644
--- a/src/utils/SkPatchUtils.cpp
+++ b/src/utils/SkPatchUtils.cpp
@@ -10,6 +10,38 @@
 #include "SkColorPriv.h"
 #include "SkGeometry.h"
 
+namespace {
+    enum CubicCtrlPts {
+        kTopP0_CubicCtrlPts = 0,
+        kTopP1_CubicCtrlPts = 1,
+        kTopP2_CubicCtrlPts = 2,
+        kTopP3_CubicCtrlPts = 3,
+
+        kRightP0_CubicCtrlPts = 3,
+        kRightP1_CubicCtrlPts = 4,
+        kRightP2_CubicCtrlPts = 5,
+        kRightP3_CubicCtrlPts = 6,
+
+        kBottomP0_CubicCtrlPts = 9,
+        kBottomP1_CubicCtrlPts = 8,
+        kBottomP2_CubicCtrlPts = 7,
+        kBottomP3_CubicCtrlPts = 6,
+
+        kLeftP0_CubicCtrlPts = 0,
+        kLeftP1_CubicCtrlPts = 11,
+        kLeftP2_CubicCtrlPts = 10,
+        kLeftP3_CubicCtrlPts = 9,
+    };
+
+    // Enum for corner also clockwise.
+    enum Corner {
+        kTopLeft_Corner = 0,
+        kTopRight_Corner,
+        kBottomRight_Corner,
+        kBottomLeft_Corner
+    };
+}
+
 /**
  * Evaluator to sample the values of a cubic bezier using forward differences.
  * Forward differences is a method for evaluating a nth degree polynomial at a uniform step by only
@@ -118,19 +150,19 @@ SkISize SkPatchUtils::GetLevelOfDetail(const SkPoint cubics[12], const SkMatrix*
 
     // Approximate length of each cubic.
     SkPoint pts[kNumPtsCubic];
-    SkPatchUtils::getTopCubic(cubics, pts);
+    SkPatchUtils::GetTopCubic(cubics, pts);
     matrix->mapPoints(pts, kNumPtsCubic);
     SkScalar topLength = approx_arc_length(pts, kNumPtsCubic);
 
-    SkPatchUtils::getBottomCubic(cubics, pts);
+    SkPatchUtils::GetBottomCubic(cubics, pts);
     matrix->mapPoints(pts, kNumPtsCubic);
     SkScalar bottomLength = approx_arc_length(pts, kNumPtsCubic);
 
-    SkPatchUtils::getLeftCubic(cubics, pts);
+    SkPatchUtils::GetLeftCubic(cubics, pts);
     matrix->mapPoints(pts, kNumPtsCubic);
     SkScalar leftLength = approx_arc_length(pts, kNumPtsCubic);
 
-    SkPatchUtils::getRightCubic(cubics, pts);
+    SkPatchUtils::GetRightCubic(cubics, pts);
     matrix->mapPoints(pts, kNumPtsCubic);
     SkScalar rightLength = approx_arc_length(pts, kNumPtsCubic);
 
@@ -141,177 +173,34 @@ SkISize SkPatchUtils::GetLevelOfDetail(const SkPoint cubics[12], const SkMatrix*
     return SkISize::Make(SkMax32(8, lodX), SkMax32(8, lodY));
 }
 
-void SkPatchUtils::getTopCubic(const SkPoint cubics[12], SkPoint points[4]) {
+void SkPatchUtils::GetTopCubic(const SkPoint cubics[12], SkPoint points[4]) {
     points[0] = cubics[kTopP0_CubicCtrlPts];
     points[1] = cubics[kTopP1_CubicCtrlPts];
     points[2] = cubics[kTopP2_CubicCtrlPts];
     points[3] = cubics[kTopP3_CubicCtrlPts];
 }
 
-void SkPatchUtils::getBottomCubic(const SkPoint cubics[12], SkPoint points[4]) {
+void SkPatchUtils::GetBottomCubic(const SkPoint cubics[12], SkPoint points[4]) {
     points[0] = cubics[kBottomP0_CubicCtrlPts];
     points[1] = cubics[kBottomP1_CubicCtrlPts];
     points[2] = cubics[kBottomP2_CubicCtrlPts];
     points[3] = cubics[kBottomP3_CubicCtrlPts];
 }
 
-void SkPatchUtils::getLeftCubic(const SkPoint cubics[12], SkPoint points[4]) {
+void SkPatchUtils::GetLeftCubic(const SkPoint cubics[12], SkPoint points[4]) {
     points[0] = cubics[kLeftP0_CubicCtrlPts];
     points[1] = cubics[kLeftP1_CubicCtrlPts];
     points[2] = cubics[kLeftP2_CubicCtrlPts];
     points[3] = cubics[kLeftP3_CubicCtrlPts];
 }
 
-void SkPatchUtils::getRightCubic(const SkPoint cubics[12], SkPoint points[4]) {
+void SkPatchUtils::GetRightCubic(const SkPoint cubics[12], SkPoint points[4]) {
     points[0] = cubics[kRightP0_CubicCtrlPts];
     points[1] = cubics[kRightP1_CubicCtrlPts];
     points[2] = cubics[kRightP2_CubicCtrlPts];
     points[3] = cubics[kRightP3_CubicCtrlPts];
 }
 
-bool SkPatchUtils::getVertexData(SkPatchUtils::VertexData* data, const SkPoint cubics[12],
-                   const SkColor colors[4], const SkPoint texCoords[4], int lodX, int lodY) {
-    if (lodX < 1 || lodY < 1 || nullptr == cubics || nullptr == data) {
-        return false;
-    }
-
-    // check for overflow in multiplication
-    const int64_t lodX64 = (lodX + 1),
-                   lodY64 = (lodY + 1),
-                   mult64 = lodX64 * lodY64;
-    if (mult64 > SK_MaxS32) {
-        return false;
-    }
-    data->fVertexCount = SkToS32(mult64);
-
-    // it is recommended to generate draw calls of no more than 65536 indices, so we never generate
-    // more than 60000 indices. To accomplish that we resize the LOD and vertex count
-    if (data->fVertexCount > 10000 || lodX > 200 || lodY > 200) {
-        SkScalar weightX = static_cast<SkScalar>(lodX) / (lodX + lodY);
-        SkScalar weightY = static_cast<SkScalar>(lodY) / (lodX + lodY);
-
-        // 200 comes from the 100 * 2 which is the max value of vertices because of the limit of
-        // 60000 indices ( sqrt(60000 / 6) that comes from data->fIndexCount = lodX * lodY * 6)
-        lodX = static_cast<int>(weightX * 200);
-        lodY = static_cast<int>(weightY * 200);
-        data->fVertexCount = (lodX + 1) * (lodY + 1);
-    }
-    data->fIndexCount = lodX * lodY * 6;
-
-    data->fPoints = new SkPoint[data->fVertexCount];
-    data->fIndices = new uint16_t[data->fIndexCount];
-
-    // if colors is not null then create array for colors
-    SkPMColor colorsPM[kNumCorners];
-    if (colors) {
-        // premultiply colors to avoid color bleeding.
-        for (int i = 0; i < kNumCorners; i++) {
-            colorsPM[i] = SkPreMultiplyColor(colors[i]);
-        }
-        data->fColors = new uint32_t[data->fVertexCount];
-    }
-
-    // if texture coordinates are not null then create array for them
-    if (texCoords) {
-        data->fTexCoords = new SkPoint[data->fVertexCount];
-    }
-
-    SkPoint pts[kNumPtsCubic];
-    SkPatchUtils::getBottomCubic(cubics, pts);
-    FwDCubicEvaluator fBottom(pts);
-    SkPatchUtils::getTopCubic(cubics, pts);
-    FwDCubicEvaluator fTop(pts);
-    SkPatchUtils::getLeftCubic(cubics, pts);
-    FwDCubicEvaluator fLeft(pts);
-    SkPatchUtils::getRightCubic(cubics, pts);
-    FwDCubicEvaluator fRight(pts);
-
-    fBottom.restart(lodX);
-    fTop.restart(lodX);
-
-    SkScalar u = 0.0f;
-    int stride = lodY + 1;
-    for (int x = 0; x <= lodX; x++) {
-        SkPoint bottom = fBottom.next(), top = fTop.next();
-        fLeft.restart(lodY);
-        fRight.restart(lodY);
-        SkScalar v = 0.f;
-        for (int y = 0; y <= lodY; y++) {
-            int dataIndex = x * (lodY + 1) + y;
-
-            SkPoint left = fLeft.next(), right = fRight.next();
-
-            SkPoint s0 = SkPoint::Make((1.0f - v) * top.x() + v * bottom.x(),
-                                       (1.0f - v) * top.y() + v * bottom.y());
-            SkPoint s1 = SkPoint::Make((1.0f - u) * left.x() + u * right.x(),
-                                       (1.0f - u) * left.y() + u * right.y());
-            SkPoint s2 = SkPoint::Make(
-                                       (1.0f - v) * ((1.0f - u) * fTop.getCtrlPoints()[0].x()
-                                                     + u * fTop.getCtrlPoints()[3].x())
-                                       + v * ((1.0f - u) * fBottom.getCtrlPoints()[0].x()
-                                              + u * fBottom.getCtrlPoints()[3].x()),
-                                       (1.0f - v) * ((1.0f - u) * fTop.getCtrlPoints()[0].y()
-                                                     + u * fTop.getCtrlPoints()[3].y())
-                                       + v * ((1.0f - u) * fBottom.getCtrlPoints()[0].y()
-                                              + u * fBottom.getCtrlPoints()[3].y()));
-            data->fPoints[dataIndex] = s0 + s1 - s2;
-
-            if (colors) {
-                uint8_t a = uint8_t(bilerp(u, v,
-                                   SkScalar(SkColorGetA(colorsPM[kTopLeft_Corner])),
-                                   SkScalar(SkColorGetA(colorsPM[kTopRight_Corner])),
-                                   SkScalar(SkColorGetA(colorsPM[kBottomLeft_Corner])),
-                                   SkScalar(SkColorGetA(colorsPM[kBottomRight_Corner]))));
-                uint8_t r = uint8_t(bilerp(u, v,
-                                   SkScalar(SkColorGetR(colorsPM[kTopLeft_Corner])),
-                                   SkScalar(SkColorGetR(colorsPM[kTopRight_Corner])),
-                                   SkScalar(SkColorGetR(colorsPM[kBottomLeft_Corner])),
-                                   SkScalar(SkColorGetR(colorsPM[kBottomRight_Corner]))));
-                uint8_t g = uint8_t(bilerp(u, v,
-                                   SkScalar(SkColorGetG(colorsPM[kTopLeft_Corner])),
-                                   SkScalar(SkColorGetG(colorsPM[kTopRight_Corner])),
-                                   SkScalar(SkColorGetG(colorsPM[kBottomLeft_Corner])),
-                                   SkScalar(SkColorGetG(colorsPM[kBottomRight_Corner]))));
-                uint8_t b = uint8_t(bilerp(u, v,
-                                   SkScalar(SkColorGetB(colorsPM[kTopLeft_Corner])),
-                                   SkScalar(SkColorGetB(colorsPM[kTopRight_Corner])),
-                                   SkScalar(SkColorGetB(colorsPM[kBottomLeft_Corner])),
-                                   SkScalar(SkColorGetB(colorsPM[kBottomRight_Corner]))));
-                data->fColors[dataIndex] = SkPackARGB32(a,r,g,b);
-            }
-
-            if (texCoords) {
-                data->fTexCoords[dataIndex] = SkPoint::Make(
-                                            bilerp(u, v, texCoords[kTopLeft_Corner].x(),
-                                                   texCoords[kTopRight_Corner].x(),
-                                                   texCoords[kBottomLeft_Corner].x(),
-                                                   texCoords[kBottomRight_Corner].x()),
-                                            bilerp(u, v, texCoords[kTopLeft_Corner].y(),
-                                                   texCoords[kTopRight_Corner].y(),
-                                                   texCoords[kBottomLeft_Corner].y(),
-                                                   texCoords[kBottomRight_Corner].y()));
-
-            }
-
-            if(x < lodX && y < lodY) {
-                int i = 6 * (x * lodY + y);
-                data->fIndices[i] = x * stride + y;
-                data->fIndices[i + 1] = x * stride + 1 + y;
-                data->fIndices[i + 2] = (x + 1) * stride + 1 + y;
-                data->fIndices[i + 3] = data->fIndices[i];
-                data->fIndices[i + 4] = data->fIndices[i + 2];
-                data->fIndices[i + 5] = (x + 1) * stride + y;
-            }
-            v = SkScalarClampMax(v + 1.f / lodY, 1);
-        }
-        u = SkScalarClampMax(u + 1.f / lodX, 1);
-    }
-    return true;
-
-}
-
-///////////////////////////////////////////////////////////////////////////////////////////////////
-
 sk_sp<SkVertices> SkPatchUtils::MakeVertices(const SkPoint cubics[12], const SkColor srcColors[4],
                                             const SkPoint srcTexCoords[4], int lodX, int lodY) {
     if (lodX < 1 || lodY < 1 || nullptr == cubics) {
@@ -365,13 +254,13 @@ sk_sp<SkVertices> SkPatchUtils::MakeVertices(const SkPoint cubics[12], const SkC
     }
 
     SkPoint pts[kNumPtsCubic];
-    SkPatchUtils::getBottomCubic(cubics, pts);
+    SkPatchUtils::GetBottomCubic(cubics, pts);
     FwDCubicEvaluator fBottom(pts);
-    SkPatchUtils::getTopCubic(cubics, pts);
+    SkPatchUtils::GetTopCubic(cubics, pts);
     FwDCubicEvaluator fTop(pts);
-    SkPatchUtils::getLeftCubic(cubics, pts);
+    SkPatchUtils::GetLeftCubic(cubics, pts);
     FwDCubicEvaluator fLeft(pts);
-    SkPatchUtils::getRightCubic(cubics, pts);
+    SkPatchUtils::GetRightCubic(cubics, pts);
     FwDCubicEvaluator fRight(pts);
 
     fBottom.restart(lodX);
diff --git a/src/utils/SkPatchUtils.h b/src/utils/SkPatchUtils.h
index c1e8ac1c2f..6d6e3491b6 100644
--- a/src/utils/SkPatchUtils.h
+++ b/src/utils/SkPatchUtils.h
@@ -15,66 +15,7 @@
 class SK_API SkPatchUtils {
 
 public:
-    // DEPRECATED -- use MakeVertices()
-    /**
-     * Structure that holds the vertex data related to the tessellation of a patch. It is passed
-     * as a parameter to the function getVertexData which sets the points, colors and texture
-     * coordinates of the vertices and the indices for them to be drawn as triangles.
-     */
-    struct VertexData {
-        int fVertexCount, fIndexCount;
-        SkPoint* fPoints;
-        SkPoint* fTexCoords;
-        uint32_t* fColors;
-        uint16_t* fIndices;
-
-        VertexData()
-        : fVertexCount(0)
-        , fIndexCount(0)
-        , fPoints(nullptr)
-        , fTexCoords(nullptr)
-        , fColors(nullptr)
-        , fIndices(nullptr) { }
-
-        ~VertexData() {
-            delete[] fPoints;
-            delete[] fTexCoords;
-            delete[] fColors;
-            delete[] fIndices;
-        }
-    };
-
     // Enums for control points based on the order specified in the constructor (clockwise).
-    enum CubicCtrlPts {
-        kTopP0_CubicCtrlPts = 0,
-        kTopP1_CubicCtrlPts = 1,
-        kTopP2_CubicCtrlPts = 2,
-        kTopP3_CubicCtrlPts = 3,
-
-        kRightP0_CubicCtrlPts = 3,
-        kRightP1_CubicCtrlPts = 4,
-        kRightP2_CubicCtrlPts = 5,
-        kRightP3_CubicCtrlPts = 6,
-
-        kBottomP0_CubicCtrlPts = 9,
-        kBottomP1_CubicCtrlPts = 8,
-        kBottomP2_CubicCtrlPts = 7,
-        kBottomP3_CubicCtrlPts = 6,
-
-        kLeftP0_CubicCtrlPts = 0,
-        kLeftP1_CubicCtrlPts = 11,
-        kLeftP2_CubicCtrlPts = 10,
-        kLeftP3_CubicCtrlPts = 9,
-    };
-
-    // Enum for corner also clockwise.
-    enum Corner {
-        kTopLeft_Corner = 0,
-        kTopRight_Corner,
-        kBottomRight_Corner,
-        kBottomLeft_Corner
-    };
-
     enum {
         kNumCtrlPts = 12,
         kNumCorners = 4,
@@ -82,43 +23,29 @@ public:
     };
 
     /**
-     * Method that calculates a level of detail (number of subdivisions) for a patch in both axis.
-     */
-    static SkISize GetLevelOfDetail(const SkPoint cubics[12], const SkMatrix* matrix);
-
-    /**
      * Get the points corresponding to the top cubic of cubics.
      */
-    static void getTopCubic(const SkPoint cubics[12], SkPoint points[4]);
+    static void GetTopCubic(const SkPoint cubics[12], SkPoint points[4]);
 
     /**
      * Get the points corresponding to the bottom cubic of cubics.
      */
-    static void getBottomCubic(const SkPoint cubics[12], SkPoint points[4]);
+    static void GetBottomCubic(const SkPoint cubics[12], SkPoint points[4]);
 
     /**
      * Get the points corresponding to the left cubic of cubics.
      */
-    static void getLeftCubic(const SkPoint cubics[12], SkPoint points[4]);
+    static void GetLeftCubic(const SkPoint cubics[12], SkPoint points[4]);
 
     /**
      * Get the points corresponding to the right cubic of cubics.
      */
-    static void getRightCubic(const SkPoint cubics[12], SkPoint points[4]);
+    static void GetRightCubic(const SkPoint cubics[12], SkPoint points[4]);
 
-    // DEPRECATED -- use MakeVertices()
     /**
-     * Function that evaluates the coons patch interpolation.
-     * data refers to the pointer of the PatchData struct in which the tessellation data is set.
-     * cubics refers to the points of the cubics.
-     * lod refers the level of detail for each axis.
-     * colors refers to the corner colors that will be bilerp across the patch (optional parameter)
-     * texCoords refers to the corner texture coordinates that will be bilerp across the patch
-        (optional parameter)
+     * Method that calculates a level of detail (number of subdivisions) for a patch in both axis.
      */
-    static bool getVertexData(SkPatchUtils::VertexData* data, const SkPoint cubics[12],
-                              const SkColor colors[4], const SkPoint texCoords[4],
-                              int lodX, int lodY);
+    static SkISize GetLevelOfDetail(const SkPoint cubics[12], const SkMatrix* matrix);
 
     static sk_sp<SkVertices> MakeVertices(const SkPoint cubics[12], const SkColor colors[4],
                                           const SkPoint texCoords[4], int lodX, int lodY);