add gpu backend (not hooked up yet)

git-svn-id: http://skia.googlecode.com/svn/trunk@649 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 140 insertions, 0 deletions

diff --git a/gpu/src/GrDrawMesh.cpp b/gpu/src/GrDrawMesh.cpp
new file mode 100644
index 0000000000..bd79005762
--- /dev/null
+++ b/gpu/src/GrDrawMesh.cpp
@@ -0,0 +1,140 @@
+#include "GrMesh.h"
+#include "SkCanvas.h"
+
+GrMesh::GrMesh() : fPts(NULL), fCount(0), fIndices(NULL), fIndexCount(0) {}
+
+GrMesh::~GrMesh() {
+    delete[] fPts;
+    delete[] fIndices;
+}
+
+GrMesh& GrMesh::operator=(const GrMesh& src) {
+    delete[] fPts;
+    delete[] fIndices;
+
+    fBounds = src.fBounds;
+    fRows = src.fRows;
+    fCols = src.fCols;
+
+    fCount = src.fCount;
+    fPts = new SkPoint[fCount * 2];
+    fTex = fPts + fCount;
+    memcpy(fPts, src.fPts, fCount * 2 * sizeof(SkPoint));
+    
+    delete[] fIndices;
+    fIndexCount = src.fIndexCount;
+    fIndices = new uint16_t[fIndexCount];
+    memcpy(fIndices, src.fIndices, fIndexCount * sizeof(uint16_t));
+
+    return *this;
+}
+
+void GrMesh::init(const SkRect& bounds, int rows, int cols,
+                const SkRect& texture) {
+    SkASSERT(rows > 0 && cols > 0);
+
+    fBounds = bounds;
+    fRows = rows;
+    fCols = cols;
+
+    delete[] fPts;
+    fCount = (rows + 1) * (cols + 1);
+    fPts = new SkPoint[fCount * 2];
+    fTex = fPts + fCount;
+
+    delete[] fIndices;
+    fIndexCount = rows * cols * 6;
+    fIndices = new uint16_t[fIndexCount];
+    
+    SkPoint* pts = fPts;
+    const SkScalar dx = bounds.width() / rows;
+    const SkScalar dy = bounds.height() / cols;
+    SkPoint* tex = fTex;
+    const SkScalar dtx = texture.width() / rows;
+    const SkScalar dty = texture.height() / cols;
+    uint16_t* idx = fIndices;
+    int index = 0;
+    for (int y = 0; y <= cols; y++) {
+        for (int x = 0; x <= rows; x++) {
+            pts->set(bounds.fLeft + x*dx, bounds.fTop + y*dy);
+            pts += 1;
+            tex->set(texture.fLeft + x*dtx, texture.fTop + y*dty);
+            tex += 1;
+            
+            if (y < cols && x < rows) {
+                *idx++ = index;
+                *idx++ = index + rows + 1;
+                *idx++ = index + 1;
+
+                *idx++ = index + 1;
+                *idx++ = index + rows + 1;
+                *idx++ = index + rows + 2;
+                
+                index += 1;
+            }
+        }
+        index += 1;
+    }
+}
+
+void GrMesh::draw(SkCanvas* canvas, const SkPaint& paint) {
+    canvas->drawVertices(SkCanvas::kTriangles_VertexMode, fCount,
+                         fPts, fTex, NULL, NULL, fIndices, fIndexCount,
+                         paint);
+}
+
+/////////////////////////////////////////////
+
+#include "SkBoundaryPatch.h"
+#include "SkMeshUtils.h"
+
+static SkPoint SkPointInterp(const SkPoint& a, const SkPoint& b, SkScalar t) {
+    return SkPoint::Make(SkScalarInterp(a.fX, b.fX, t),
+                         SkScalarInterp(a.fY, b.fY, t));
+}
+
+static void set_cubic(SkPoint pts[4], SkScalar x0, SkScalar y0,
+                      SkScalar x3, SkScalar y3, SkScalar scale = 1) {
+    SkPoint tmp, tmp2;
+    
+    pts[0].set(x0, y0);
+    pts[3].set(x3, y3);
+    
+    tmp = SkPointInterp(pts[0], pts[3], SK_Scalar1/3);
+    tmp2 = pts[0] - tmp;
+    tmp2.rotateCW();
+    tmp2.scale(scale);
+    pts[1] = tmp + tmp2;
+    
+    tmp = SkPointInterp(pts[0], pts[3], 2*SK_Scalar1/3);
+    tmp2 = pts[3] - tmp;
+    tmp2.rotateCW();
+    tmp2.scale(scale);
+    pts[2] = tmp + tmp2;
+}
+
+void test_patch(SkCanvas* canvas, const SkBitmap& bm, SkScalar scale) {
+    const float w = bm.width();
+    const float h = bm.height();
+    SkCubicBoundary cubic;    
+    set_cubic(cubic.fPts + 0, 0, 0, w, 0, scale);
+    set_cubic(cubic.fPts + 3, w, 0, w, h, scale);
+    set_cubic(cubic.fPts + 6, w, h, 0, h, -scale);
+    set_cubic(cubic.fPts + 9, 0, h, 0, 0, scale);
+    
+    SkBoundaryPatch patch;
+    patch.setBoundary(&cubic);
+    
+    const int Rows = 16;
+    const int Cols = 16;
+    SkPoint pts[Rows * Cols];
+    patch.evalPatch(pts, Rows, Cols);
+    
+    SkPaint paint;
+    paint.setAntiAlias(true);
+    paint.setFilterBitmap(true);
+
+    SkMeshUtils::Draw(canvas, bm, Rows, Cols, pts, NULL, paint);
+}
+
+