Brian Salomon | cbcb0a1 | 2017-11-19 13:20:13 -0500 | [diff] [blame] | 1 | /* |
| 2 | * Copyright 2017 Google Inc. |
| 3 | * |
| 4 | * Use of this source code is governed by a BSD-style license that can be |
| 5 | * found in the LICENSE file. |
| 6 | */ |
| 7 | |
Brian Salomon | b508696 | 2017-12-13 10:59:33 -0500 | [diff] [blame^] | 8 | #include "SkPoint3.h" |
Brian Salomon | cbcb0a1 | 2017-11-19 13:20:13 -0500 | [diff] [blame] | 9 | #include "SkRefCnt.h" |
| 10 | |
| 11 | #ifndef SkAtlasTextRenderer_DEFINED |
| 12 | #define SkAtlasTextRenderer_DEFINED |
| 13 | |
| 14 | /** |
| 15 | * This is the base class for a renderer implemented by the SkAtlasText client. The |
| 16 | * SkAtlasTextContext issues texture creations, deletions, uploads, and vertex draws to the |
| 17 | * renderer. The renderer must perform those actions in the order called to correctly render |
| 18 | * the text drawn to SkAtlasTextTargets. |
| 19 | */ |
| 20 | class SK_API SkAtlasTextRenderer : public SkRefCnt { |
| 21 | public: |
| 22 | enum class AtlasFormat { |
| 23 | /** Unsigned normalized 8 bit single channel format. */ |
| 24 | kA8 |
| 25 | }; |
| 26 | |
| 27 | struct SDFVertex { |
Brian Salomon | b508696 | 2017-12-13 10:59:33 -0500 | [diff] [blame^] | 28 | /** Position in device space (not normalized). The third component is w (not z). */ |
| 29 | SkPoint3 fPosition; |
Brian Salomon | cbcb0a1 | 2017-11-19 13:20:13 -0500 | [diff] [blame] | 30 | /** Color, same value for all four corners of a glyph quad. */ |
| 31 | uint32_t fColor; |
| 32 | /** Texture coordinate (in texel units, not normalized). */ |
| 33 | SkIPoint16 fTextureCoord; |
| 34 | }; |
| 35 | |
| 36 | virtual ~SkAtlasTextRenderer() = default; |
| 37 | |
| 38 | /** |
| 39 | * Create a texture of the provided format with dimensions 'width' x 'height' |
| 40 | * and return a unique handle. |
| 41 | */ |
| 42 | virtual void* createTexture(AtlasFormat, int width, int height) = 0; |
| 43 | |
| 44 | /** |
| 45 | * Delete the texture with the passed handle. |
| 46 | */ |
| 47 | virtual void deleteTexture(void* textureHandle) = 0; |
| 48 | |
| 49 | /** |
| 50 | * Place the pixel data specified by 'data' in the texture with handle |
| 51 | * 'textureHandle' in the rectangle ['x', 'x' + 'width') x ['y', 'y' + 'height'). |
| 52 | * 'rowBytes' specifies the byte offset between successive rows in 'data' and will always be |
| 53 | * a multiple of the number of bytes per pixel. |
| 54 | * The pixel format of data is the same as that of 'textureHandle'. |
| 55 | */ |
| 56 | virtual void setTextureData(void* textureHandle, const void* data, int x, int y, int width, |
| 57 | int height, size_t rowBytes) = 0; |
| 58 | |
| 59 | /** |
| 60 | * Draws glyphs using SDFs. The SDF data resides in 'textureHandle'. The array |
| 61 | * 'vertices' provides interleaved device-space positions, colors, and |
| 62 | * texture coordinates. There are are 4 * 'quadCnt' entries in 'vertices'. |
| 63 | */ |
| 64 | virtual void drawSDFGlyphs(void* targetHandle, void* textureHandle, const SDFVertex vertices[], |
| 65 | int quadCnt) = 0; |
| 66 | |
| 67 | /** Called when a SkAtlasTextureTarget is destroyed. */ |
| 68 | virtual void targetDeleted(void* targetHandle) = 0; |
| 69 | }; |
| 70 | |
| 71 | #endif |