SkTextBlob

gm/textblob.cpp

+/*
+ * 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 "gm.h"
+
+#include "SkCanvas.h"
+#include "SkPoint.h"
+#include "SkTextBlob.h"
+#include "SkTDArray.h"
+
+namespace  {
+
+enum Pos {
+    kDefault_Pos = 0,
+    kScalar_Pos  = 1,
+    kPoint_Pos   = 2,
+};
+
+const struct BlobCfg {
+    unsigned count;
+    Pos      pos;
+    SkScalar scale;
+} blobConfigs[][3][3] = {
+    {
+        { { 1024, kDefault_Pos, 1 }, { 0, kDefault_Pos, 0 }, { 0, kDefault_Pos, 0 } },
+        { { 1024,  kScalar_Pos, 1 }, { 0,  kScalar_Pos, 0 }, { 0,  kScalar_Pos, 0 } },
+        { { 1024,   kPoint_Pos, 1 }, { 0,   kPoint_Pos, 0 }, { 0,   kPoint_Pos, 0 } },
+    },
+    {
+        { { 4, kDefault_Pos, 1},     { 4, kDefault_Pos, 1},  { 4, kDefault_Pos, 1} },
+        { { 4,  kScalar_Pos, 1},     { 4,  kScalar_Pos, 1},  { 4,  kScalar_Pos, 1} },
+        { { 4,   kPoint_Pos, 1},     { 4,   kPoint_Pos, 1},  { 4,   kPoint_Pos, 1} },
+    },
+
+    {
+        { { 4, kDefault_Pos, 1},     { 4, kDefault_Pos, 1},  { 4,  kScalar_Pos, 1} },
+        { { 4,  kScalar_Pos, 1},     { 4,  kScalar_Pos, 1},  { 4,   kPoint_Pos, 1} },
+        { { 4,   kPoint_Pos, 1},     { 4,   kPoint_Pos, 1},  { 4, kDefault_Pos, 1} },
+    },
+
+    {
+        { { 4, kDefault_Pos, 1},     { 4,  kScalar_Pos, 1},  { 4,   kPoint_Pos, 1} },
+        { { 4,  kScalar_Pos, 1},     { 4,   kPoint_Pos, 1},  { 4, kDefault_Pos, 1} },
+        { { 4,   kPoint_Pos, 1},     { 4, kDefault_Pos, 1},  { 4,  kScalar_Pos, 1} },
+    },
+};
+
+const SkScalar kFontSize = 16;
+}
+
+class TextBlobGM : public skiagm::GM {
+public:
+    TextBlobGM(const char* txt) {
+        SkPaint p;
+        size_t txtLen = strlen(txt);
+        int glyphCount = p.textToGlyphs(txt, txtLen, NULL);
+
+        fGlyphs.append(glyphCount);
+        p.textToGlyphs(txt, txtLen, fGlyphs.begin());
+    }
+
+protected:
+    virtual SkString onShortName() SK_OVERRIDE {
+        return SkString("textblob");
+    }
+
+    virtual SkISize onISize() SK_OVERRIDE {
+        return SkISize::Make(640, 480);
+    }
+
+    virtual void onDraw(SkCanvas* canvas) SK_OVERRIDE {
+        for (unsigned b = 0; b < SK_ARRAY_COUNT(blobConfigs); ++b) {
+            SkAutoTUnref<const SkTextBlob> blob(makeBlob(b));
+
+            SkPaint p;
+            p.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+            p.setTextSize(kFontSize);
+            p.setAntiAlias(true);
+            p.setSubpixelText(true);
+
+            SkPoint offset = SkPoint::Make(SkIntToScalar(10 + 300 * (b % 2)),
+                                           SkIntToScalar(20 + 150 * (b / 2)));
+
+            canvas->drawTextBlob(blob, offset.x(), offset.y(), p);
+
+            p.setColor(SK_ColorBLUE);
+            p.setStyle(SkPaint::kStroke_Style);
+            SkRect box = blob->bounds();
+            box.offset(offset);
+            canvas->drawRect(box, p);
+
+        }
+    }
+
+private:
+    const SkTextBlob* makeBlob(unsigned blobIndex) {
+        SkTextBlobBuilder builder;
+
+        SkPaint font;
+        font.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
+
+        for (unsigned l = 0; l < SK_ARRAY_COUNT(blobConfigs[blobIndex]); ++l) {
+            unsigned currentGlyph = 0;
+
+            for (unsigned c = 0; c < SK_ARRAY_COUNT(blobConfigs[blobIndex][l]); ++c) {
+                const BlobCfg* cfg = &blobConfigs[blobIndex][l][c];
+                unsigned count = cfg->count;
+
+                if (count > fGlyphs.count() - currentGlyph) {
+                    count = fGlyphs.count() - currentGlyph;
+                }
+                if (0 == count) {
+                    break;
+                }
+
+                font.setTextSize(kFontSize * cfg->scale);
+                const SkScalar advanceX = font.getTextSize() * 0.85f;
+                const SkScalar advanceY = font.getTextSize() * 1.5f;
+
+                SkPoint offset = SkPoint::Make(currentGlyph * advanceX + c * advanceX,
+                                               advanceY * l);
+                switch (cfg->pos) {
+                case kDefault_Pos: {
+                    const SkTextBlobBuilder::RunBuffer& buf = builder.allocRun(font, count,
+                                                                               offset.x(),
+                                                                               offset.y());
+                    memcpy(buf.glyphs, fGlyphs.begin() + currentGlyph, count * sizeof(uint16_t));
+                } break;
+                case kScalar_Pos: {
+                    const SkTextBlobBuilder::RunBuffer& buf = builder.allocRunPosH(font, count,
+                                                                                   offset.y());
+                    SkTDArray<SkScalar> pos;
+                    for (unsigned i = 0; i < count; ++i) {
+                        *pos.append() = offset.x() + i * advanceX;
+                    }
+
+                    memcpy(buf.glyphs, fGlyphs.begin() + currentGlyph, count * sizeof(uint16_t));
+                    memcpy(buf.pos, pos.begin(), count * sizeof(SkScalar));
+                } break;
+                case kPoint_Pos: {
+                    const SkTextBlobBuilder::RunBuffer& buf = builder.allocRunPos(font, count);
+
+                    SkTDArray<SkScalar> pos;
+                    for (unsigned i = 0; i < count; ++i) {
+                        *pos.append() = offset.x() + i * advanceX;
+                        *pos.append() = offset.y() + i * (advanceY / count);
+                    }
+
+                    memcpy(buf.glyphs, fGlyphs.begin() + currentGlyph, count * sizeof(uint16_t));
+                    memcpy(buf.pos, pos.begin(), count * sizeof(SkScalar) * 2);
+                } break;
+                default:
+                    SkFAIL("unhandled pos value");
+                }
+
+                currentGlyph += count;
+            }
+        }
+
+        return builder.build();
+    }
+
+    SkTDArray<uint16_t> fGlyphs;
+
+    typedef skiagm::GM INHERITED;
+};
+
+DEF_GM( return SkNEW_ARGS(TextBlobGM, ("hamburgefons")); )