SkPatchGrid interface (after SkPatch/SkPicture rebase).

src/utils/SkPatchGrid.cpp

Index: src/utils/SkPatchGrid.cpp
diff --git a/src/utils/SkPatchGrid.cpp b/src/utils/SkPatchGrid.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..b1fea574037b9e894de4cc323ff8ef24d790ea2d
--- /dev/null
+++ b/src/utils/SkPatchGrid.cpp
@@ -0,0 +1,188 @@
+/*
+ * 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, VertexType flags, SkXfermode* xfer)
+    : fRows(0)
+    , fCols(0)
+    , fModeFlags(kNone_VertexType)
+    , fCornerPts(NULL)
+    , fCornerColors(NULL)
+    , fTexCoords(NULL)
+    , fHrzCtrlPts(NULL)
+    , fVrtCtrlPts(NULL)
+    , fXferMode(NULL) {
+        this->reset(rows, cols, flags, xfer);
+}
+
+SkPatchGrid::~SkPatchGrid() {
+    SkDELETE_ARRAY(fCornerPts);
+    SkDELETE_ARRAY(fCornerColors);
+    SkDELETE_ARRAY(fTexCoords);
+    SkDELETE_ARRAY(fHrzCtrlPts);
+    SkDELETE_ARRAY(fVrtCtrlPts);
+}
+
+bool SkPatchGrid::setPatch(int x, int y, const SkPoint cubics[12], const SkColor colors[4],
+                           const SkPoint texCoords[4]) {
+    // Check for the passed paramaters to be within the range of the grid dimensions and a valid
+    // pointer for the cubics' control points.
+    if (x < 0 || y < 0 || x > fCols - 1 || y > fRows - 1 || NULL == cubics) {
+        return false;
+    }
+    
+    // setup corners and colors
+    int cornerPos = y * (fCols + 1) + x;
+    fCornerPts[cornerPos] = cubics[SkPatchUtils::kTopP0_CubicCtrlPts];
+    fCornerPts[cornerPos + 1] = cubics[SkPatchUtils::kTopP3_CubicCtrlPts];
+    fCornerPts[cornerPos + (fCols + 1)] = cubics[SkPatchUtils::kBottomP0_CubicCtrlPts];
+    fCornerPts[cornerPos + (fCols + 1) + 1] = cubics[SkPatchUtils::kBottomP3_CubicCtrlPts];
+    
+    // set horizontal control points
+    int hrzPos = y * (fCols * 2) + (x * 2);
+    fHrzCtrlPts[hrzPos] = cubics[SkPatchUtils::kTopP1_CubicCtrlPts];
+    fHrzCtrlPts[hrzPos + 1] = cubics[SkPatchUtils::kTopP2_CubicCtrlPts];
+    fHrzCtrlPts[hrzPos + (fCols * 2)] = cubics[SkPatchUtils::kBottomP1_CubicCtrlPts];
+    fHrzCtrlPts[hrzPos + (fCols * 2) + 1] = cubics[SkPatchUtils::kBottomP2_CubicCtrlPts];
+    
+    // set vertical control points
+    int vrtPos = (y*2) * (fCols + 1) + x;
+    fVrtCtrlPts[vrtPos] = cubics[SkPatchUtils::kLeftP1_CubicCtrlPts];
+    fVrtCtrlPts[vrtPos + 1] = cubics[SkPatchUtils::kRightP1_CubicCtrlPts];
+    fVrtCtrlPts[vrtPos + (fCols + 1)] = cubics[SkPatchUtils::kLeftP2_CubicCtrlPts];
+    fVrtCtrlPts[vrtPos + (fCols + 1) + 1] = cubics[SkPatchUtils::kRightP2_CubicCtrlPts];
+    
+    // set optional values (colors and texture coordinates)
+    if ((fModeFlags & kColors_VertexType)  && NULL != colors) {
+        fCornerColors[cornerPos] = colors[0];
+        fCornerColors[cornerPos + 1] = colors[1];
+        fCornerColors[cornerPos + (fCols + 1)] = colors[3];
+        fCornerColors[cornerPos + (fCols + 1) + 1] = colors[2];
+    }
+    
+    if ((fModeFlags & kTexs_VertexType) && NULL != texCoords) {
+        fTexCoords[cornerPos] = texCoords[0];
+        fTexCoords[cornerPos + 1] = texCoords[1];
+        fTexCoords[cornerPos + (fCols + 1)] = texCoords[3];
+        fTexCoords[cornerPos + (fCols + 1) + 1] = texCoords[2];
+    }
+    
+    return true;
+}
+
+bool SkPatchGrid::getPatch(int x, int y, SkPoint cubics[12], SkColor colors[4],
+                           SkPoint texCoords[4]) const {
+    
+    if (x < 0 || y < 0 || x > fCols - 1 || y > fRows - 1 || NULL == cubics) {
+        return false;
+    }
+    
+    // set the patch by building the array of points and colors with the corresponding values.
+    int cornerPos = y * (fCols + 1) + x;
+    cubics[SkPatchUtils::kTopP0_CubicCtrlPts] = fCornerPts[cornerPos];
+    cubics[SkPatchUtils::kTopP3_CubicCtrlPts] = fCornerPts[cornerPos + 1];
+    cubics[SkPatchUtils::kBottomP0_CubicCtrlPts] = fCornerPts[cornerPos + (fCols + 1)];
+    cubics[SkPatchUtils::kBottomP3_CubicCtrlPts] = fCornerPts[cornerPos + (fCols + 1) + 1];
+    
+    int hrzPos = y * (fCols * 2) + (x * 2);
+    cubics[SkPatchUtils::kTopP1_CubicCtrlPts] = fHrzCtrlPts[hrzPos];
+    cubics[SkPatchUtils::kTopP2_CubicCtrlPts] = fHrzCtrlPts[hrzPos + 1];
+    cubics[SkPatchUtils::kBottomP1_CubicCtrlPts] = fHrzCtrlPts[hrzPos + (fCols * 2)];
+    cubics[SkPatchUtils::kBottomP2_CubicCtrlPts] = fHrzCtrlPts[hrzPos + (fCols * 2) + 1];
+    
+    int vrtPos = (y*2) * (fCols + 1) + x;
+    cubics[SkPatchUtils::kLeftP1_CubicCtrlPts] = fVrtCtrlPts[vrtPos];
+    cubics[SkPatchUtils::kRightP1_CubicCtrlPts] = fVrtCtrlPts[vrtPos + 1];
+    cubics[SkPatchUtils::kLeftP2_CubicCtrlPts] = fVrtCtrlPts[vrtPos + (fCols + 1)];
+    cubics[SkPatchUtils::kRightP2_CubicCtrlPts] = fVrtCtrlPts[vrtPos + (fCols + 1) + 1];
+    
+    if ((fModeFlags & kColors_VertexType)  && NULL != colors) {
+        colors[0] = fCornerColors[cornerPos];
+        colors[1] = fCornerColors[cornerPos + 1];
+        colors[3] = fCornerColors[cornerPos + (fCols + 1)];
+        colors[2] = fCornerColors[cornerPos + (fCols + 1) + 1];
+    }
+    
+    if ((fModeFlags & kTexs_VertexType)  && NULL != texCoords) {
+        texCoords[0] = fTexCoords[cornerPos];
+        texCoords[1] = fTexCoords[cornerPos + 1];
+        texCoords[3] = fTexCoords[cornerPos + (fCols + 1)];
+        texCoords[2] = fTexCoords[cornerPos + (fCols + 1) + 1];
+    }
+    
+    return true;
+}
+
+void SkPatchGrid::reset(int rows, int cols, VertexType flags, SkXfermode* xMode) {
+    SkDELETE_ARRAY(fCornerPts);
+    SkDELETE_ARRAY(fCornerColors);
+    SkDELETE_ARRAY(fTexCoords);
+    SkDELETE_ARRAY(fHrzCtrlPts);
+    SkDELETE_ARRAY(fVrtCtrlPts);
+    
+    fCols = cols;
+    fRows = rows;
+    fModeFlags = flags;
+    fXferMode = xMode;
+    
+    fCornerPts = SkNEW_ARRAY(SkPoint, (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(fHrzCtrlPts, 0, (fRows + 1) * fCols * 2 * sizeof(SkPoint));
+    memset(fVrtCtrlPts, 0, fRows * 2 * (fCols + 1) * sizeof(SkPoint));
+    
+    if (fModeFlags & kColors_VertexType) {
+        fCornerColors = SkNEW_ARRAY(SkColor, (fRows + 1) * (fCols + 1));
+        memset(fCornerColors, 0, (fRows + 1) * (fCols + 1) * sizeof(SkColor));
+    }
+    
+    if (fModeFlags & kTexs_VertexType) {
+        fTexCoords = SkNEW_ARRAY(SkPoint, (fRows + 1) * (fCols + 1));
+        memset(fTexCoords, 0, (fRows + 1) * (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++) {
+            SkPoint cubics[12];
+            this->getPatch(x, y, cubics, NULL, NULL);
+            SkMatrix matrix = canvas->getTotalMatrix();
+            SkISize lod = SkPatchUtils::GetLevelOfDetail(cubics, &matrix);
+            maxCols[x] = SkMax32(maxCols[x], lod.width());
+            maxRows[y] = SkMax32(maxRows[y], lod.height());
+        }
+    }
+    // Draw the patches by generating their geometry with the maximum level of detail per axis.
+    for (int x = 0; x < fCols; x++) {
+        for (int y = 0; y < fRows; y++) {
+            SkPoint cubics[12];
+            SkPoint texCoords[4];
+            SkColor colors[4];
+            this->getPatch(x, y, cubics, colors, texCoords);
+            SkPatchUtils::VertexData data;
+            SkPatchUtils::getVertexData(&data, cubics,
+                                        fModeFlags & kColors_VertexType ? colors : NULL,
+                                        fModeFlags & kTexs_VertexType ? texCoords : NULL,
+                                        maxCols[x], maxRows[y]);
+            canvas->drawVertices(SkCanvas::kTriangles_VertexMode, data.fVertexCount,
+                                 data.fPoints, data.fTexCoords, data.fColors, fXferMode,
+                                 data.fIndices, data.fIndexCount, paint);
+        }
+    }
+    SkDELETE_ARRAY(maxCols);
+    SkDELETE_ARRAY(maxRows);
+}