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- /*
- * 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 "include/core/SkPoint3.h"
- #include "include/core/SkRefCnt.h"
- #ifndef SkAtlasTextRenderer_DEFINED
- #define SkAtlasTextRenderer_DEFINED
- /**
- * This is the base class for a renderer implemented by the SkAtlasText client. The
- * SkAtlasTextContext issues texture creations, deletions, uploads, and vertex draws to the
- * renderer. The renderer must perform those actions in the order called to correctly render
- * the text drawn to SkAtlasTextTargets.
- */
- class SK_API SkAtlasTextRenderer : public SkRefCnt {
- public:
- enum class AtlasFormat {
- /** Unsigned normalized 8 bit single channel format. */
- kA8
- };
- struct SDFVertex {
- /** 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). */
- int16_t fTextureCoordX;
- int16_t fTextureCoordY;
- };
- virtual ~SkAtlasTextRenderer() = default;
- /**
- * Create a texture of the provided format with dimensions 'width' x 'height'
- * and return a unique handle.
- */
- virtual void* createTexture(AtlasFormat, int width, int height) = 0;
- /**
- * Delete the texture with the passed handle.
- */
- virtual void deleteTexture(void* textureHandle) = 0;
- /**
- * Place the pixel data specified by 'data' in the texture with handle
- * 'textureHandle' in the rectangle ['x', 'x' + 'width') x ['y', 'y' + 'height').
- * 'rowBytes' specifies the byte offset between successive rows in 'data' and will always be
- * a multiple of the number of bytes per pixel.
- * The pixel format of data is the same as that of 'textureHandle'.
- */
- virtual void setTextureData(void* textureHandle, const void* data, int x, int y, int width,
- int height, size_t rowBytes) = 0;
- /**
- * Draws glyphs using SDFs. The SDF data resides in 'textureHandle'. The array
- * 'vertices' provides interleaved device-space positions, colors, and
- * texture coordinates. There are are 4 * 'quadCnt' entries in 'vertices'.
- */
- virtual void drawSDFGlyphs(void* targetHandle, void* textureHandle, const SDFVertex vertices[],
- int quadCnt) = 0;
- /** Called when a SkAtlasTextureTarget is destroyed. */
- virtual void targetDeleted(void* targetHandle) = 0;
- };
- #endif
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