SkPatchGrid interface (after SkPatch/SkPicture rebase).

src/core/SkPatchGrid.cpp

Index: src/core/SkPatchGrid.cpp
diff --git a/src/core/SkPatchGrid.cpp b/src/core/SkPatchGrid.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..69dad9a437a1c76c0b38635b58f2ff2308a945f7
--- /dev/null
+++ b/src/core/SkPatchGrid.cpp
@@ -0,0 +1,155 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include "SkPatchGrid.h"
+#include "SkPatchUtils.h"
+
+SkPatchGrid::SkPatchGrid(int rows, int cols)
+    : fRows(rows)
+    , fCols(cols)
+    , fCornerPts(NULL)
+    , fCornerColors(NULL)
+    , fHrzCtrlPts(NULL)
+    , fVrtCtrlPts(NULL) {
+        this->reset(fRows, fCols);
+}
+
+SkPatchGrid::~SkPatchGrid() {
+    SkDELETE_ARRAY(fCornerPts);
+    SkDELETE_ARRAY(fCornerColors);
+    SkDELETE_ARRAY(fHrzCtrlPts);
+    SkDELETE_ARRAY(fVrtCtrlPts);
+}
+
+bool SkPatchGrid::setPatch(int x, int y, const SkPoint ctrlPts[12], const SkColor colors[4]) {
+    // Check for the passed paramaters to be within the range of the mesh gradient dimensions.
+    if (x < 0 || y < 0 || x > fCols - 1 || y > fRows - 1) {
+        return false;
+    }
+    
+    //setup corners and colors
+    int cornerPos = y * (fCols + 1) + x;
+    fCornerPts[cornerPos] = ctrlPts[SkPatch::kTopP0_CubicCtrlPts];
+    fCornerPts[cornerPos + 1] = ctrlPts[SkPatch::kTopP3_CubicCtrlPts];
+    fCornerPts[cornerPos + (fCols + 1)] = ctrlPts[SkPatch::kBottomP0_CubicCtrlPts];
+    fCornerPts[cornerPos + (fCols + 1) + 1] = ctrlPts[SkPatch::kBottomP3_CubicCtrlPts];
+    
+    fCornerColors[cornerPos] = colors[0];
+    fCornerColors[cornerPos + 1] = colors[1];
+    fCornerColors[cornerPos + (fCols + 1)] = colors[3];
+    fCornerColors[cornerPos + (fCols + 1) + 1] = colors[2];
+    
+    // set horizontal control points
+    int hrzPos = y * (fCols * 2) + (x * 2);
+    fHrzCtrlPts[hrzPos] = ctrlPts[SkPatch::kTopP1_CubicCtrlPts];
+    fHrzCtrlPts[hrzPos + 1] = ctrlPts[SkPatch::kTopP2_CubicCtrlPts];
+    fHrzCtrlPts[hrzPos + (fCols * 2)] = ctrlPts[SkPatch::kBottomP1_CubicCtrlPts];
+    fHrzCtrlPts[hrzPos + (fCols * 2) + 1] = ctrlPts[SkPatch::kBottomP2_CubicCtrlPts];
+    
+    int vrtPos = (y*2) * (fCols + 1) + x;
+    fVrtCtrlPts[vrtPos] = ctrlPts[SkPatch::kLeftP1_CubicCtrlPts];
+    fVrtCtrlPts[vrtPos + 1] = ctrlPts[SkPatch::kRightP1_CubicCtrlPts];
+    fVrtCtrlPts[vrtPos + (fCols + 1)] = ctrlPts[SkPatch::kLeftP2_CubicCtrlPts];
+    fVrtCtrlPts[vrtPos + (fCols + 1) + 1] = ctrlPts[SkPatch::kRightP2_CubicCtrlPts];
+    return true;
+}
+
+bool SkPatchGrid::setPatch(int x, int y, const SkPatch& patch) {
+    return this->setPatch(x, y, patch.getControlPoints(), patch.getColors());
+}
+
+void SkPatchGrid::getPatch(int x, int y, SkPatch* patch) const {
+    
+    if (x < 0 || y < 0 || x > fCols - 1 || y > fRows - 1) {
+        return;
+    }
+    
+    if (NULL != patch) {
+        //set the patch by building the array of points and colors with the corresponding values.
+        
+        SkPoint ctrlPts[12];
+        SkColor colors[4];
+        
+        int cornerPos = y * (fCols + 1) + x;
+        ctrlPts[SkPatch::kTopP0_CubicCtrlPts] = fCornerPts[cornerPos];
+        ctrlPts[SkPatch::kTopP3_CubicCtrlPts] = fCornerPts[cornerPos + 1];
+        ctrlPts[SkPatch::kBottomP0_CubicCtrlPts] = fCornerPts[cornerPos + (fCols + 1)];
+        ctrlPts[SkPatch::kBottomP3_CubicCtrlPts] = fCornerPts[cornerPos + (fCols + 1) + 1];
+        
+        colors[0] = fCornerColors[cornerPos];
+        colors[1] = fCornerColors[cornerPos + 1];
+        colors[3] = fCornerColors[cornerPos + (fCols + 1)];
+        colors[2] = fCornerColors[cornerPos + (fCols + 1) + 1];
+        
+        int hrzPos = y * (fCols * 2) + (x * 2);
+        ctrlPts[SkPatch::kTopP1_CubicCtrlPts] = fHrzCtrlPts[hrzPos];
+        ctrlPts[SkPatch::kTopP2_CubicCtrlPts] = fHrzCtrlPts[hrzPos + 1];
+        ctrlPts[SkPatch::kBottomP1_CubicCtrlPts] = fHrzCtrlPts[hrzPos + (fCols * 2)];
+        ctrlPts[SkPatch::kBottomP2_CubicCtrlPts] = fHrzCtrlPts[hrzPos + (fCols * 2) + 1];
+        
+        int vrtPos = (y*2) * (fCols + 1) + x;
+        ctrlPts[SkPatch::kLeftP1_CubicCtrlPts] = fVrtCtrlPts[vrtPos];
+        ctrlPts[SkPatch::kRightP1_CubicCtrlPts] = fVrtCtrlPts[vrtPos + 1];
+        ctrlPts[SkPatch::kLeftP2_CubicCtrlPts] = fVrtCtrlPts[vrtPos + (fCols + 1)];
+        ctrlPts[SkPatch::kRightP2_CubicCtrlPts] = fVrtCtrlPts[vrtPos + (fCols + 1) + 1];
+        
+        patch->reset(ctrlPts, colors);
+    }
+}
+
+void SkPatchGrid::reset(int rows, int cols) {
+    SkDELETE_ARRAY(fCornerPts);
+    SkDELETE_ARRAY(fCornerColors);
+    SkDELETE_ARRAY(fHrzCtrlPts);
+    SkDELETE_ARRAY(fVrtCtrlPts);
+    
+    fCols = cols;
+    fRows = rows;
+    
+    fCornerPts = SkNEW_ARRAY(SkPoint, (fRows + 1) * (fCols + 1));
+    fCornerColors = SkNEW_ARRAY(SkColor, (fRows + 1) * (fCols + 1));
+    fHrzCtrlPts = SkNEW_ARRAY(SkPoint, (fRows + 1) * fCols * 2);
+    fVrtCtrlPts = SkNEW_ARRAY(SkPoint, fRows * 2 * (fCols + 1));
+    
+    memset(fCornerPts, 0, (fRows + 1) * (fCols + 1) * sizeof(SkPoint));
+    memset(fCornerColors, 0, (fRows + 1) * (fCols + 1) * sizeof(SkColor));
+    memset(fHrzCtrlPts, 0, (fRows + 1) * fCols * 2 * sizeof(SkPoint));
+    memset(fVrtCtrlPts, 0, fRows * 2 * (fCols + 1) * sizeof(SkPoint));
+}
+
+void SkPatchGrid::draw(SkCanvas* canvas, SkPaint& paint) {
+    int* maxCols = SkNEW_ARRAY(int, fCols);
+    int* maxRows = SkNEW_ARRAY(int, fRows);
+    memset(maxCols, 0, fCols * sizeof(int));
+    memset(maxRows, 0, fRows * sizeof(int));
+    
+    // Get the maximum level of detail per axis for each row and column
+    for (int y = 0; y < fRows; y++) {
+        for (int x = 0; x < fCols; x++) {
+            SkPatch patch;
+            this->getPatch(x, y, &patch);
+            SkMatrix matrix = canvas->getTotalMatrix();
+            SkISize lod = SkPatchUtils::GetLevelOfDetail(patch, &matrix);
+            maxCols[x] = SkMax32(maxCols[x], lod.width());
+            maxRows[y] = SkMax32(maxRows[y], lod.height());
+        }
+    }
+    // Draw the patches by generating their mesh with the maximum level of detail per axis.
+    for (int y = 0; y < fRows; y++) {
+        for (int x = 0; x < fCols; x++) {
+            SkPatch patch;
+            this->getPatch(x, y, &patch);
+            SkPatch::VertexData data;
+            patch.getVertexData(&data, maxCols[x], maxRows[y]);
+            canvas->drawVertices(SkCanvas::kTriangles_VertexMode, data.fVertexCount,
+                                 data.fPoints, data.fTexCoords, data.fColors, NULL,
+                                 data.fIndices, data.fIndexCount, paint);
+        }
+    }
+    SkDELETE_ARRAY(maxCols);
+    SkDELETE_ARRAY(maxRows);
+}