PDF: Add text support with a font framework (font embedding to come).

Supports fakeBold, underline, strikethrough, mode (fill, stroke, both), size, skew, alignment (left, center, right).
Missing is drawFontOnPath and font lookup and embedding.
Changed SkPDFString to support how it is used from drawText methods.
Moved compile assert into SkTypes.
Moved constants and utility function used to support fakeBold, underline, and strikethrough into higher level locations.

Review URL: http://codereview.appspot.com/2946041

git-svn-id: http://skia.googlecode.com/svn/trunk@624 2bbb7eff-a529-9590-31e7-b0007b416f81

1 files changed, 199 insertions, 0 deletions

diff --git a/src/pdf/SkPDFFont.cpp b/src/pdf/SkPDFFont.cpp
new file mode 100644
index 0000000000..1bbc53af4e
--- /dev/null
+++ b/src/pdf/SkPDFFont.cpp
@@ -0,0 +1,199 @@
+/*
+ * Copyright (C) 2010 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#include "SkPaint.h"
+#include "SkPDFFont.h"
+#include "SkUtils.h"
+
+namespace {
+
+uint16_t unicharToWinAnsiGlyphID(SkUnichar uniChar) {
+    // TODO(vandebo) Quick hack to get text working.  Either finish the
+    // implementation of this, or remove it and use the encoding built into
+    // the real font.
+    if (uniChar < ' ')
+        return 0;
+    if (uniChar < '~')
+        return uniChar;
+    return 0;
+}
+
+}
+
+SkPDFFont::~SkPDFFont() {
+    SkAutoMutexAcquire lock(canonicalFontsMutex());
+    int index = find(fFontID);
+    SkASSERT(index >= 0);
+    canonicalFonts().removeShuffle(index);
+}
+
+void SkPDFFont::getResources(SkTDArray<SkPDFObject*>* resourceList) {
+    resourceList->setReserve(resourceList->count() + fResources.count());
+    for (int i = 0; i < fResources.count(); i++) {
+        resourceList->push(fResources[i]);
+        fResources[i]->ref();
+        fResources[i]->getResources(resourceList);
+    }
+}
+
+uint32_t SkPDFFont::fontID() {
+    return fFontID;
+}
+
+bool SkPDFFont::multiByteGlyphs() {
+    return fMultiByteGlyphs;
+}
+
+// TODO(vandebo) This function goes or stays with unicharToWinAnsiGlyphID.
+int SkPDFFont::textToPDFGlyphs(const void* text, size_t byteLength,
+                               const SkPaint& paint, uint16_t glyphs[],
+                               size_t glyphsLength) const {
+    // For a regular, non built-in font, just ask the paint.
+    if (fResources.count() != 0) {
+        SkASSERT(glyphsLength >= byteLength / 2);
+        if (paint.getTextEncoding() == SkPaint::kGlyphID_TextEncoding) {
+            memcpy(glyphs, text, byteLength / 2 * 2);
+            return byteLength / 2;
+        } else {
+            return paint.textToGlyphs(text, byteLength, glyphs);
+        }
+    }
+
+    const char* data = (const char*)text;
+    const char* stop = data + byteLength;
+    const uint16_t* data16 = (const uint16_t*)data;
+    const uint16_t* stop16 = (const uint16_t*)stop;
+    uint16_t* gPtr = glyphs;
+    uint16_t* gEnd = glyphs + glyphsLength;
+
+    // For a built-in font (no resources), we may have to undo glyph encoding
+    // before converting to the standard pdf encoding.
+    switch(paint.getTextEncoding()) {
+        case SkPaint::kUTF8_TextEncoding:
+            while (data < stop && gPtr < gEnd)
+                *gPtr++ = unicharToWinAnsiGlyphID(SkUTF8_NextUnichar(&data));
+            SkASSERT(data >= stop);
+            break;
+        case SkPaint::kUTF16_TextEncoding:
+            while (data16 < stop16 && gPtr < gEnd)
+                *gPtr++ = unicharToWinAnsiGlyphID(SkUTF16_NextUnichar(&data16));
+            SkASSERT(data16 >= stop16);
+            break;
+        case SkPaint::kGlyphID_TextEncoding:
+            while (data16 < stop16 && gPtr < gEnd) {
+                SkUnichar buf;
+                paint.glyphsToUnichars(data16++, 1, &buf);
+                *gPtr++ = unicharToWinAnsiGlyphID(buf);
+            }
+            SkASSERT(data16 >= stop16);
+            break;
+        default:
+            SkASSERT(!"Unknown text encoding");
+            break;
+    }
+    return gPtr - glyphs;
+}
+
+// static
+SkPDFFont* SkPDFFont::getFontResouceByID(uint32_t fontID) {
+    SkAutoMutexAcquire lock(canonicalFontsMutex());
+    int index = find(fontID);
+    if (index >= 0) {
+        canonicalFonts()[index].fFont->ref();
+        return canonicalFonts()[index].fFont;
+    }
+
+    // TODO(vandebo) Lookup and create the font. For now, just use the built-in
+    // Helevtica.
+    SkPDFFont* font = new SkPDFFont(fontID, false);
+    font->populateBuiltinFont("Helvetica");
+
+    FontRec newEntry(font, fontID);
+    canonicalFonts().push(newEntry);
+    return font;  // Return the reference new SkPDFFont() created.
+}
+
+// static
+SkTDArray<SkPDFFont::FontRec>& SkPDFFont::canonicalFonts() {
+    // This initialization is only thread safe with gcc.
+    static SkTDArray<FontRec> gCanonicalFonts;
+    return gCanonicalFonts;
+}
+
+// static
+SkMutex& SkPDFFont::canonicalFontsMutex() {
+    // This initialization is only thread safe with gcc.
+    static SkMutex gCanonicalFontsMutex;
+    return gCanonicalFontsMutex;
+}
+
+// static
+int SkPDFFont::find(uint32_t fontID) {
+    FontRec search(NULL, fontID);
+    return canonicalFonts().find(search);
+}
+
+SkPDFFont::SkPDFFont(uint32_t fontID, bool multiByteGlyphs)
+    : fFontID(fontID),
+      fMultiByteGlyphs(multiByteGlyphs) {
+}
+
+void SkPDFFont::populateBuiltinFont(const char fontName[]) {
+    SkASSERT(strcmp(fontName, "Time-Roman") == 0 ||
+             strcmp(fontName, "Time-Bold") == 0 ||
+             strcmp(fontName, "Time-Italic") == 0 ||
+             strcmp(fontName, "Time-BoldItalic") == 0 ||
+             strcmp(fontName, "Helvetica") == 0 ||
+             strcmp(fontName, "Helvetica-Bold") == 0 ||
+             strcmp(fontName, "Helvetica-Oblique") == 0 ||
+             strcmp(fontName, "Helvetica-BoldOblique") == 0 ||
+             strcmp(fontName, "Courier") == 0 ||
+             strcmp(fontName, "Courier-Bold") == 0 ||
+             strcmp(fontName, "Courier-Oblique") == 0 ||
+             strcmp(fontName, "Courier-BoldOblique") == 0 ||
+             strcmp(fontName, "Symbol") == 0 ||
+             strcmp(fontName, "ZapfDingbats") == 0);
+
+    SkRefPtr<SkPDFName> type = new SkPDFName("Font");
+    type->unref();  // SkRefPtr and new both took a reference.
+    insert("Type", type.get());
+
+    SkRefPtr<SkPDFName> subType = new SkPDFName("Type1");
+    subType->unref();  // SkRefPtr and new both took a reference.
+    insert("Subtype", subType.get());
+
+    SkRefPtr<SkPDFName> baseFont = new SkPDFName(fontName);
+    baseFont->unref();  // SkRefPtr and new both took a reference.
+    insert("BaseFont", baseFont.get());
+
+    SkRefPtr<SkPDFName> encoding = new SkPDFName("WinAnsiEncoding");
+    encoding->unref();  // SkRefPtr and new both took a reference.
+    insert("Encoding", encoding.get());
+}
+
+void SkPDFFont::populateFont(const char subType[], const char fontName[],
+                             int firstChar, int lastChar, int widths[],
+                             SkPDFObject* fontDescriptor) {
+}
+
+bool SkPDFFont::FontRec::operator==(const SkPDFFont::FontRec& b) const {
+    return fFontID == b.fFontID;
+}
+
+SkPDFFont::FontRec::FontRec(SkPDFFont* font, uint32_t fontID)
+    : fFont(font),
+      fFontID(fontID) {
+}