Revert "Revert "Add Atlas Text interface for rendering SDF glyphs.""

This reverts commit 9c2202ffc22b4293b48a4edeafa1b5d2bab8bb83.

Bug: skia:
Change-Id: I482ddf74f8e40d3d0908c840ba5c6ff981ccefbd
Reviewed-on: https://skia-review.googlesource.com/73345
Reviewed-by: Brian Salomon <bsalomon@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>

1 files changed, 123 insertions, 0 deletions

diff --git a/gm/atlastext.cpp b/gm/atlastext.cpp
new file mode 100644
index 0000000000..b8acb0fcc7
--- /dev/null
+++ b/gm/atlastext.cpp
@@ -0,0 +1,123 @@
+/*
+ * Copyright 2017 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"
+
+#if SK_SUPPORT_ATLAS_TEXT
+
+#include "SkAtlasTextContext.h"
+#include "SkAtlasTextFont.h"
+#include "SkAtlasTextTarget.h"
+#include "SkBitmap.h"
+#include "SkCanvas.h"
+#include "SkTypeface.h"
+#include "gpu/TestContext.h"
+#include "gpu/atlastext/GLTestAtlasTextRenderer.h"
+#include "gpu/atlastext/TestAtlasTextRenderer.h"
+#include "sk_tool_utils.h"
+
+// GM that draws text using the Atlas Text interface offscreen and then blits that to the canvas.
+
+static SkScalar draw_string(SkAtlasTextTarget* target, const SkString& text, SkScalar x, SkScalar y,
+                            uint32_t color, sk_sp<SkTypeface> typeface, float size) {
+    auto font = SkAtlasTextFont::Make(std::move(typeface), size);
+    target->drawText(text.c_str(), text.size(), x, y, color, *font);
+    SkPaint paint;
+    paint.setTextSize(size);
+    return x + paint.measureText(text.c_str(), text.size());
+}
+
+class AtlasTextGM : public skiagm::GM {
+public:
+    AtlasTextGM() = default;
+
+protected:
+    SkString onShortName() override { return SkString("atlastext"); }
+
+    SkISize onISize() override { return SkISize::Make(kSize, kSize); }
+
+    void onOnceBeforeDraw() override {
+        fRenderer = sk_gpu_test::MakeGLTestAtlasTextRenderer();
+        if (!fRenderer) {
+            return;
+        }
+        fContext = SkAtlasTextContext::Make(fRenderer);
+        auto targetHandle = fRenderer->makeTargetHandle(kSize, kSize);
+        fTarget = SkAtlasTextTarget::Make(fContext, kSize, kSize, targetHandle);
+
+        fTypefaces[0] = sk_tool_utils::create_portable_typeface("serif", SkFontStyle::Italic());
+        fTypefaces[1] =
+                sk_tool_utils::create_portable_typeface("sans-serif", SkFontStyle::Italic());
+        fTypefaces[2] = sk_tool_utils::create_portable_typeface("serif", SkFontStyle::Normal());
+        fTypefaces[3] =
+                sk_tool_utils::create_portable_typeface("sans-serif", SkFontStyle::Normal());
+        fTypefaces[4] = sk_tool_utils::create_portable_typeface("serif", SkFontStyle::Bold());
+        fTypefaces[5] = sk_tool_utils::create_portable_typeface("sans-serif", SkFontStyle::Bold());
+    }
+
+    void onDraw(SkCanvas* canvas) override {
+        if (!fRenderer) {
+            canvas->clear(SK_ColorRED);
+            return;
+        }
+        auto bmp = this->drawText();
+        SkPaint paint;
+        paint.setBlendMode(SkBlendMode::kSrc);
+        canvas->drawBitmap(bmp, 0, 0);
+    }
+
+private:
+    SkBitmap drawText() {
+        static const int kSizes[] = {8, 13, 18, 23, 30};
+
+        static const SkString kTexts[] = {SkString("ABCDEFGHIJKLMNOPQRSTUVWXYZ"),
+                                          SkString("abcdefghijklmnopqrstuvwxyz"),
+                                          SkString("0123456789"),
+                                          SkString("!@#$%^&*()<>[]{}")};
+        SkScalar x = 0;
+        SkScalar y = 10;
+
+        SkRandom random;
+        do {
+            for (auto s : kSizes) {
+                auto size = 2 * s;
+                for (const auto& typeface : fTypefaces) {
+                    for (const auto& text : kTexts) {
+                        uint32_t color = random.nextU();
+                        x = size + draw_string(fTarget.get(), text, x, y, color, typeface, size);
+                        x = SkScalarCeilToScalar(x);
+                        if (x + 100 > kSize) {
+                            x = 0;
+                            y += SkScalarCeilToScalar(size + 3);
+                            if (y > kSize) {
+                                fTarget->flush();
+                                return fRenderer->readTargetHandle(fTarget->handle());
+                            }
+                        }
+                    }
+                }
+            }
+        } while (true);
+    }
+
+    static constexpr int kSize = 1280;
+
+    sk_sp<SkTypeface> fTypefaces[6];
+    sk_sp<sk_gpu_test::TestAtlasTextRenderer> fRenderer;
+    std::unique_ptr<SkAtlasTextTarget> fTarget;
+    sk_sp<SkAtlasTextContext> fContext;
+
+    typedef GM INHERITED;
+};
+
+constexpr int AtlasTextGM::kSize;
+
+//////////////////////////////////////////////////////////////////////////////
+
+DEF_GM(return new AtlasTextGM;)
+
+#endif