SkPatchGrid interface (after SkPatch/SkPicture rebase).

src/effects/gradients/SkMeshGradient.cpp

Index: src/effects/gradients/SkMeshGradient.cpp
diff --git a/src/effects/gradients/SkMeshGradient.cpp b/src/effects/gradients/SkMeshGradient.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..3755a242a0cb0885bc111270afa43906f698d489
--- /dev/null
+++ b/src/effects/gradients/SkMeshGradient.cpp
@@ -0,0 +1,236 @@
+/*
+ * 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 "SkMeshGradient.h"
+#include "SkPatchUtils.h"
+
+SkMeshGradient::SkMeshGradient(int rows, int cols)
+    : fRows(rows)
+    , fCols(cols)
+    , fCornerPts(NULL)
+    , fCornerColors(NULL)
+    , fHrzCtrlPts(NULL)
+    , fVrtCtrlPts(NULL) {
+        this->reset(fRows, fCols, NULL, NULL, NULL, NULL);
+}
+
+SkMeshGradient::SkMeshGradient(int rows, int cols, const SkPoint* corners,
+                               const SkPoint* hrzCtrlPts, const SkPoint* vrtCtrlPts,
+                               const SkColor* colors)
+: fRows(rows)
+, fCols(cols)
+, fCornerPts(NULL)
+, fCornerColors(NULL)
+, fHrzCtrlPts(NULL)
+, fVrtCtrlPts(NULL) {
+    this->reset(fRows, fCols, corners, hrzCtrlPts, vrtCtrlPts, colors);
+}
+
+SkMeshGradient::~SkMeshGradient() {
+    SkDELETE_ARRAY(fCornerPts);
+    SkDELETE_ARRAY(fCornerColors);
+    SkDELETE_ARRAY(fHrzCtrlPts);
+    SkDELETE_ARRAY(fVrtCtrlPts);
+}
+
+bool SkMeshGradient::addPatch(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 SkMeshGradient::addPatch(int x, int y, const SkPatch& patch) {
+    return this->addPatch(x, y, patch.getControlPoints(), patch.getColors());
+}
+
+void SkMeshGradient::getPatchAt(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 SkMeshGradient::resize(int rows, int cols) {
+    //save old values
+    int oldCols = fCols;
+    int oldRows = fRows;
+    
+    fCols = cols;
+    fRows = rows;
+    
+    SkPoint* pts = fCornerPts;
+    SkColor* colors = fCornerColors;
+    SkPoint* hzrPts = fHrzCtrlPts;
+    SkPoint* vrtPts = fVrtCtrlPts;
+    
+    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));
+    
+    //copy previous values that are still within the new range.
+    for (int y = 0; y < fRows; y++) {
+        for (int x = 0; x < fCols; x++) {
+            if (x >= oldCols || y >= oldRows) {
+                continue;
+            }
+            
+            int cornerPos = y * (fCols + 1) + x;
+            int oldCornerPos = y * (oldCols + 1) + x;
+            fCornerPts[cornerPos] = pts[oldCornerPos];
+            fCornerPts[cornerPos + 1] = pts[oldCornerPos + 1];
+            fCornerPts[cornerPos + (fCols + 1)] = pts[oldCornerPos + (oldCols + 1)];
+            fCornerPts[cornerPos + (fCols + 1) + 1] = pts[oldCornerPos + (oldCols + 1) + 1];
+            fCornerColors[cornerPos] = colors[oldCornerPos];
+            fCornerColors[cornerPos + 1] = colors[oldCornerPos + 1];
+            fCornerColors[cornerPos + (fCols + 1)] = colors[oldCornerPos + (oldCols + 1)];
+            fCornerColors[cornerPos + (fCols + 1) + 1] =
+                                                    colors[oldCornerPos + (oldCols + 1) + 1];
+            
+            int hrzPos = y * (fCols * 2) + (x * 2);
+            int oldHrzPos = y * (oldCols * 2) + (x * 2);
+            fHrzCtrlPts[hrzPos] = hzrPts[oldHrzPos];
+            fHrzCtrlPts[hrzPos + 1] = hzrPts[oldHrzPos + 1];
+            fHrzCtrlPts[hrzPos + (fCols * 2)] = hzrPts[oldHrzPos + (oldCols * 2)];
+            fHrzCtrlPts[hrzPos + (fCols * 2) + 1] = hzrPts[oldHrzPos + (oldCols * 2) + 1];
+            
+            int vrtPos = (y*2) * (fCols + 1) + x;
+            int oldVrtPos = (y*2) * (oldCols + 1) + x;
+            fVrtCtrlPts[vrtPos] = vrtPts[oldVrtPos];
+            fVrtCtrlPts[vrtPos + 1] = vrtPts[oldVrtPos + 1];
+            fVrtCtrlPts[vrtPos + (fCols + 1)] = vrtPts[oldVrtPos + (oldCols + 1)];
+            fVrtCtrlPts[vrtPos + (fCols + 1) + 1] = vrtPts[oldVrtPos + (oldCols + 1) + 1];
+        }
+    }
+    
+    //delete old copies.
+    SkDELETE_ARRAY(pts);
+    SkDELETE_ARRAY(colors);
+    SkDELETE_ARRAY(hzrPts);
+    SkDELETE_ARRAY(vrtPts);
+}
+
+void SkMeshGradient::reset(int rows, int cols, const SkPoint* corners, const SkPoint* hrzCtrlPts,
+                           const SkPoint* vrtCtrlPts, const SkColor* colors) {
+    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));
+    
+    if (NULL != corners) {
+        memcpy(fCornerPts, corners, (fRows + 1) * (fCols + 1) * sizeof(SkPoint));
+    }
+    if (NULL != colors) {
+        memcpy(fCornerColors, colors, (fRows + 1) * (fCols + 1) * sizeof(SkColor));
+    }
+    if (NULL != hrzCtrlPts) {
+        memcpy(fHrzCtrlPts, hrzCtrlPts, (fRows + 1) * fCols * 2 * sizeof(SkPoint));
+    }
+    if (NULL != vrtCtrlPts) {
+        memcpy(fVrtCtrlPts, vrtCtrlPts, fRows * 2 * (fCols + 1) * sizeof(SkPoint));
+    }
+}
+
+void SkMeshGradient::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->getPatchAt(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->getPatchAt(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);
+}