Add matrix stack to SkAtlasTextTarget.

Makes SkAtlasTextRenderer::SDFVertex now has a 3 component position vector.

Change-Id: I7ec1a8068fb84388a82e1748d6e9d02820d55abd
Reviewed-on: https://skia-review.googlesource.com/84202
Commit-Queue: Brian Salomon <bsalomon@google.com>
Reviewed-by: Jim Van Verth <jvanverth@google.com>

2 files changed, 37 insertions, 3 deletions

diff --git a/include/atlastext/SkAtlasTextRenderer.h b/include/atlastext/SkAtlasTextRenderer.h
index a78e270edb..f5eb5240c9 100644
--- a/include/atlastext/SkAtlasTextRenderer.h
+++ b/include/atlastext/SkAtlasTextRenderer.h
@@ -5,7 +5,7 @@
  * found in the LICENSE file.
  */
 
-#include "SkPoint.h"
+#include "SkPoint3.h"
 #include "SkRefCnt.h"
 
 #ifndef SkAtlasTextRenderer_DEFINED
@@ -25,8 +25,8 @@ public:
     };
 
     struct SDFVertex {
-        /** Position in device space (not normalized). */
-        SkPoint fPosition;
+        /** Position in device space (not normalized). The third component is w (not z). */
+        SkPoint3 fPosition;
         /** Color, same value for all four corners of a glyph quad. */
         uint32_t fColor;
         /** Texture coordinate (in texel units, not normalized). */
diff --git a/include/atlastext/SkAtlasTextTarget.h b/include/atlastext/SkAtlasTextTarget.h
index ff879617d8..c29f381dc8 100644
--- a/include/atlastext/SkAtlasTextTarget.h
+++ b/include/atlastext/SkAtlasTextTarget.h
@@ -9,11 +9,13 @@
 #define SkAtlasTextTarget_DEFINED
 
 #include <memory>
+#include "SkDeque.h"
 #include "SkRefCnt.h"
 #include "SkScalar.h"
 
 class SkAtlasTextContext;
 class SkAtlasTextFont;
+class SkMatrix;
 struct SkPoint;
 
 /** Represents a client-created renderable surface and is used to draw text into the surface. */
@@ -46,15 +48,47 @@ public:
 
     SkAtlasTextContext* context() const { return fContext.get(); }
 
+    /** Saves the current matrix in a stack. Returns the prior depth of the saved matrix stack. */
+    int save();
+    /** Pops the top matrix on the stack if the stack is not empty. */
+    void restore();
+    /**
+     * Pops the matrix stack until the stack depth is count. Does nothing if the depth is already
+     * less than count.
+     */
+    void restoreToCount(int count);
+
+    /** Pre-translates the current CTM. */
+    void translate(SkScalar dx, SkScalar dy);
+    /** Pre-scales the current CTM. */
+    void scale(SkScalar sx, SkScalar sy);
+    /** Pre-rotates the current CTM about the origin. */
+    void rotate(SkScalar degrees);
+    /** Pre-rotates the current CTM about the (px, py). */
+    void rotate(SkScalar degrees, SkScalar px, SkScalar py);
+    /** Pre-skews the current CTM. */
+    void skew(SkScalar sx, SkScalar sy);
+    /** Pre-concats the current CTM. */
+    void concat(const SkMatrix& matrix);
+
 protected:
     SkAtlasTextTarget(sk_sp<SkAtlasTextContext>, int width, int height, void* handle);
 
+    const SkMatrix& ctm() const { return *static_cast<const SkMatrix*>(fMatrixStack.back()); }
+
     void* const fHandle;
     const sk_sp<SkAtlasTextContext> fContext;
     const int fWidth;
     const int fHeight;
 
 private:
+    SkDeque fMatrixStack;
+    int fSaveCnt;
+
+    SkMatrix* accessCTM() const {
+        return static_cast<SkMatrix*>(const_cast<void*>(fMatrixStack.back()));
+    }
+
     SkAtlasTextTarget() = delete;
     SkAtlasTextTarget(const SkAtlasTextContext&) = delete;
     SkAtlasTextTarget& operator=(const SkAtlasTextContext&) = delete;