GrGpu.h revision e3371304b8c06a29aa3581c8decd9046c712c5f6
1/* 2 * Copyright 2011 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 8#ifndef GrGpu_DEFINED 9#define GrGpu_DEFINED 10 11#include "GrDrawTarget.h" 12#include "GrClipMaskManager.h" 13#include "GrPathRendering.h" 14#include "SkPath.h" 15 16class GrContext; 17class GrIndexBufferAllocPool; 18class GrPath; 19class GrPathRange; 20class GrPathRenderer; 21class GrPathRendererChain; 22class GrStencilBuffer; 23class GrVertexBufferAllocPool; 24 25class GrGpu : public GrDrawTarget { 26public: 27 28 /** 29 * Additional blend coefficients for dual source blending, not exposed 30 * through GrPaint/GrContext. 31 */ 32 enum ExtendedBlendCoeffs { 33 // source 2 refers to second output color when 34 // using dual source blending. 35 kS2C_GrBlendCoeff = kPublicGrBlendCoeffCount, 36 kIS2C_GrBlendCoeff, 37 kS2A_GrBlendCoeff, 38 kIS2A_GrBlendCoeff, 39 40 kTotalGrBlendCoeffCount 41 }; 42 43 /** 44 * Create an instance of GrGpu that matches the specified backend. If the requested backend is 45 * not supported (at compile-time or run-time) this returns NULL. The context will not be 46 * fully constructed and should not be used by GrGpu until after this function returns. 47 */ 48 static GrGpu* Create(GrBackend, GrBackendContext, GrContext* context); 49 50 //////////////////////////////////////////////////////////////////////////// 51 52 GrGpu(GrContext* context); 53 virtual ~GrGpu(); 54 55 GrContext* getContext() { return this->INHERITED::getContext(); } 56 const GrContext* getContext() const { return this->INHERITED::getContext(); } 57 58 GrPathRendering* pathRendering() { 59 return fPathRendering.get(); 60 } 61 62 // Called by GrContext when the underlying backend context has been destroyed. 63 // GrGpu should use this to ensure that no backend API calls will be made from 64 // here onward, including in its destructor. Subclasses should call 65 // INHERITED::contextAbandoned() if they override this. 66 virtual void contextAbandoned(); 67 68 /** 69 * The GrGpu object normally assumes that no outsider is setting state 70 * within the underlying 3D API's context/device/whatever. This call informs 71 * the GrGpu that the state was modified and it shouldn't make assumptions 72 * about the state. 73 */ 74 void markContextDirty(uint32_t state = kAll_GrBackendState) { 75 fResetBits |= state; 76 } 77 78 void unimpl(const char[]); 79 80 /** 81 * Creates a texture object. If desc width or height is not a power of 82 * two but underlying API requires a power of two texture then srcData 83 * will be embedded in a power of two texture. The extra width and height 84 * is filled as though srcData were rendered clamped into the texture. 85 * The exception is when using compressed data formats. In this case, the 86 * desc width and height must be a multiple of the compressed format block 87 * size otherwise this function returns NULL. Similarly, if the underlying 88 * API requires a power of two texture and the source width and height are not 89 * a power of two, then this function returns NULL. 90 * 91 * If kRenderTarget_TextureFlag is specified the GrRenderTarget is 92 * accessible via GrTexture::asRenderTarget(). The texture will hold a ref 93 * on the render target until the texture is destroyed. Compressed textures 94 * cannot have the kRenderTarget_TextureFlag set. 95 * 96 * @param desc describes the texture to be created. 97 * @param srcData texel data to load texture. Begins with full-size 98 * palette data for paletted textures. For compressed 99 * formats it contains the compressed pixel data. Otherwise, 100 * it contains width*height texels. If NULL texture data 101 * is uninitialized. 102 * @param rowBytes the number of bytes between consecutive rows. Zero 103 * means rows are tightly packed. This field is ignored 104 * for compressed formats. 105 * 106 * @return The texture object if successful, otherwise NULL. 107 */ 108 GrTexture* createTexture(const GrTextureDesc& desc, 109 const void* srcData, size_t rowBytes); 110 111 /** 112 * Implements GrContext::wrapBackendTexture 113 */ 114 GrTexture* wrapBackendTexture(const GrBackendTextureDesc&); 115 116 /** 117 * Implements GrContext::wrapBackendTexture 118 */ 119 GrRenderTarget* wrapBackendRenderTarget(const GrBackendRenderTargetDesc&); 120 121 /** 122 * Creates a vertex buffer. 123 * 124 * @param size size in bytes of the vertex buffer 125 * @param dynamic hints whether the data will be frequently changed 126 * by either GrVertexBuffer::map() or 127 * GrVertexBuffer::updateData(). 128 * 129 * @return The vertex buffer if successful, otherwise NULL. 130 */ 131 GrVertexBuffer* createVertexBuffer(size_t size, bool dynamic); 132 133 /** 134 * Creates an index buffer. 135 * 136 * @param size size in bytes of the index buffer 137 * @param dynamic hints whether the data will be frequently changed 138 * by either GrIndexBuffer::map() or 139 * GrIndexBuffer::updateData(). 140 * 141 * @return The index buffer if successful, otherwise NULL. 142 */ 143 GrIndexBuffer* createIndexBuffer(size_t size, bool dynamic); 144 145 /** 146 * Creates a path object that can be stenciled using stencilPath(). It is 147 * only legal to call this if the caps report support for path stenciling. 148 */ 149 GrPath* createPath(const SkPath& path, const SkStrokeRec& stroke); 150 151 /** 152 * Creates a path range object that can be used to draw multiple paths via 153 * drawPaths(). It is only legal to call this if the caps report support for 154 * path rendering. 155 */ 156 GrPathRange* createPathRange(size_t size, const SkStrokeRec&); 157 158 /** 159 * Returns an index buffer that can be used to render quads. 160 * Six indices per quad: 0, 1, 2, 0, 2, 3, etc. 161 * The max number of quads can be queried using GrIndexBuffer::maxQuads(). 162 * Draw with kTriangles_GrPrimitiveType 163 * @ return the quad index buffer 164 */ 165 const GrIndexBuffer* getQuadIndexBuffer() const; 166 167 /** 168 * Resolves MSAA. 169 */ 170 void resolveRenderTarget(GrRenderTarget* target); 171 172 /** 173 * Gets a preferred 8888 config to use for writing/reading pixel data to/from a surface with 174 * config surfaceConfig. The returned config must have at least as many bits per channel as the 175 * readConfig or writeConfig param. 176 */ 177 virtual GrPixelConfig preferredReadPixelsConfig(GrPixelConfig readConfig, 178 GrPixelConfig surfaceConfig) const { 179 return readConfig; 180 } 181 virtual GrPixelConfig preferredWritePixelsConfig(GrPixelConfig writeConfig, 182 GrPixelConfig surfaceConfig) const { 183 return writeConfig; 184 } 185 186 /** 187 * Called before uploading writing pixels to a GrTexture when the src pixel config doesn't 188 * match the texture's config. 189 */ 190 virtual bool canWriteTexturePixels(const GrTexture*, GrPixelConfig srcConfig) const = 0; 191 192 /** 193 * OpenGL's readPixels returns the result bottom-to-top while the skia 194 * API is top-to-bottom. Thus we have to do a y-axis flip. The obvious 195 * solution is to have the subclass do the flip using either the CPU or GPU. 196 * However, the caller (GrContext) may have transformations to apply and can 197 * simply fold in the y-flip for free. On the other hand, the subclass may 198 * be able to do it for free itself. For example, the subclass may have to 199 * do memcpys to handle rowBytes that aren't tight. It could do the y-flip 200 * concurrently. 201 * 202 * This function returns true if a y-flip is required to put the pixels in 203 * top-to-bottom order and the subclass cannot do it for free. 204 * 205 * See read pixels for the params 206 * @return true if calling readPixels with the same set of params will 207 * produce bottom-to-top data 208 */ 209 virtual bool readPixelsWillPayForYFlip(GrRenderTarget* renderTarget, 210 int left, int top, 211 int width, int height, 212 GrPixelConfig config, 213 size_t rowBytes) const = 0; 214 /** 215 * This should return true if reading a NxM rectangle of pixels from a 216 * render target is faster if the target has dimensons N and M and the read 217 * rectangle has its top-left at 0,0. 218 */ 219 virtual bool fullReadPixelsIsFasterThanPartial() const { return false; }; 220 221 /** 222 * Reads a rectangle of pixels from a render target. 223 * 224 * @param renderTarget the render target to read from. NULL means the 225 * current render target. 226 * @param left left edge of the rectangle to read (inclusive) 227 * @param top top edge of the rectangle to read (inclusive) 228 * @param width width of rectangle to read in pixels. 229 * @param height height of rectangle to read in pixels. 230 * @param config the pixel config of the destination buffer 231 * @param buffer memory to read the rectangle into. 232 * @param rowBytes the number of bytes between consecutive rows. Zero 233 * means rows are tightly packed. 234 * @param invertY buffer should be populated bottom-to-top as opposed 235 * to top-to-bottom (skia's usual order) 236 * 237 * @return true if the read succeeded, false if not. The read can fail 238 * because of a unsupported pixel config or because no render 239 * target is currently set. 240 */ 241 bool readPixels(GrRenderTarget* renderTarget, 242 int left, int top, int width, int height, 243 GrPixelConfig config, void* buffer, size_t rowBytes); 244 245 /** 246 * Updates the pixels in a rectangle of a texture. 247 * 248 * @param left left edge of the rectangle to write (inclusive) 249 * @param top top edge of the rectangle to write (inclusive) 250 * @param width width of rectangle to write in pixels. 251 * @param height height of rectangle to write in pixels. 252 * @param config the pixel config of the source buffer 253 * @param buffer memory to read pixels from 254 * @param rowBytes number of bytes between consecutive rows. Zero 255 * means rows are tightly packed. 256 */ 257 bool writeTexturePixels(GrTexture* texture, 258 int left, int top, int width, int height, 259 GrPixelConfig config, const void* buffer, 260 size_t rowBytes); 261 262 // GrDrawTarget overrides 263 virtual void clear(const SkIRect* rect, 264 GrColor color, 265 bool canIgnoreRect, 266 GrRenderTarget* renderTarget = NULL) SK_OVERRIDE; 267 268 virtual void purgeResources() SK_OVERRIDE { 269 // The clip mask manager can rebuild all its clip masks so just 270 // get rid of them all. 271 fClipMaskManager.purgeResources(); 272 } 273 274 // After the client interacts directly with the 3D context state the GrGpu 275 // must resync its internal state and assumptions about 3D context state. 276 // Each time this occurs the GrGpu bumps a timestamp. 277 // state of the 3D context 278 // At 10 resets / frame and 60fps a 64bit timestamp will overflow in about 279 // a billion years. 280 typedef uint64_t ResetTimestamp; 281 282 // This timestamp is always older than the current timestamp 283 static const ResetTimestamp kExpiredTimestamp = 0; 284 // Returns a timestamp based on the number of times the context was reset. 285 // This timestamp can be used to lazily detect when cached 3D context state 286 // is dirty. 287 ResetTimestamp getResetTimestamp() const { 288 return fResetTimestamp; 289 } 290 291 /** 292 * These methods are called by the clip manager's setupClipping function 293 * which (called as part of GrGpu's implementation of onDraw and 294 * onStencilPath member functions.) The GrGpu subclass should flush the 295 * stencil state to the 3D API in its implementation of flushGraphicsState. 296 */ 297 void enableScissor(const SkIRect& rect) { 298 fScissorState.fEnabled = true; 299 fScissorState.fRect = rect; 300 } 301 void disableScissor() { fScissorState.fEnabled = false; } 302 303 /** 304 * Like the scissor methods above this is called by setupClipping and 305 * should be flushed by the GrGpu subclass in flushGraphicsState. These 306 * stencil settings should be used in place of those on the GrDrawState. 307 * They have been adjusted to account for any interactions between the 308 * GrDrawState's stencil settings and stencil clipping. 309 */ 310 void setStencilSettings(const GrStencilSettings& settings) { 311 fStencilSettings = settings; 312 } 313 void disableStencil() { fStencilSettings.setDisabled(); } 314 315 // GrGpu subclass sets clip bit in the stencil buffer. The subclass is 316 // free to clear the remaining bits to zero if masked clears are more 317 // expensive than clearing all bits. 318 virtual void clearStencilClip(GrRenderTarget*, const SkIRect& rect, bool insideClip) = 0; 319 320 enum PrivateDrawStateStateBits { 321 kFirstBit = (GrDrawState::kLastPublicStateBit << 1), 322 323 kModifyStencilClip_StateBit = kFirstBit, // allows draws to modify 324 // stencil bits used for 325 // clipping. 326 }; 327 328 void getPathStencilSettingsForFillType(SkPath::FillType fill, GrStencilSettings* outStencilSettings); 329 330 enum DrawType { 331 kDrawPoints_DrawType, 332 kDrawLines_DrawType, 333 kDrawTriangles_DrawType, 334 kStencilPath_DrawType, 335 kDrawPath_DrawType, 336 kDrawPaths_DrawType, 337 }; 338 339 static bool IsPathRenderingDrawType(DrawType type) { 340 return kDrawPath_DrawType == type || kDrawPaths_DrawType == type; 341 } 342 343protected: 344 DrawType PrimTypeToDrawType(GrPrimitiveType type) { 345 switch (type) { 346 case kTriangles_GrPrimitiveType: 347 case kTriangleStrip_GrPrimitiveType: 348 case kTriangleFan_GrPrimitiveType: 349 return kDrawTriangles_DrawType; 350 case kPoints_GrPrimitiveType: 351 return kDrawPoints_DrawType; 352 case kLines_GrPrimitiveType: 353 case kLineStrip_GrPrimitiveType: 354 return kDrawLines_DrawType; 355 default: 356 SkFAIL("Unexpected primitive type"); 357 return kDrawTriangles_DrawType; 358 } 359 } 360 361 // prepares clip flushes gpu state before a draw 362 bool setupClipAndFlushState(DrawType, 363 const GrDeviceCoordTexture* dstCopy, 364 GrDrawState::AutoRestoreEffects* are, 365 const SkRect* devBounds); 366 367 // Functions used to map clip-respecting stencil tests into normal 368 // stencil funcs supported by GPUs. 369 static GrStencilFunc ConvertStencilFunc(bool stencilInClip, 370 GrStencilFunc func); 371 static void ConvertStencilFuncAndMask(GrStencilFunc func, 372 bool clipInStencil, 373 unsigned int clipBit, 374 unsigned int userBits, 375 unsigned int* ref, 376 unsigned int* mask); 377 378 GrClipMaskManager fClipMaskManager; 379 380 struct GeometryPoolState { 381 const GrVertexBuffer* fPoolVertexBuffer; 382 int fPoolStartVertex; 383 384 const GrIndexBuffer* fPoolIndexBuffer; 385 int fPoolStartIndex; 386 }; 387 const GeometryPoolState& getGeomPoolState() { 388 return fGeomPoolStateStack.back(); 389 } 390 391 // The state of the scissor is controlled by the clip manager 392 struct ScissorState { 393 bool fEnabled; 394 SkIRect fRect; 395 } fScissorState; 396 397 // The final stencil settings to use as determined by the clip manager. 398 GrStencilSettings fStencilSettings; 399 400 // Helpers for setting up geometry state 401 void finalizeReservedVertices(); 402 void finalizeReservedIndices(); 403 404 SkAutoTDelete<GrPathRendering> fPathRendering; 405 406private: 407 // GrDrawTarget overrides 408 virtual bool onReserveVertexSpace(size_t vertexSize, int vertexCount, void** vertices) SK_OVERRIDE; 409 virtual bool onReserveIndexSpace(int indexCount, void** indices) SK_OVERRIDE; 410 virtual void releaseReservedVertexSpace() SK_OVERRIDE; 411 virtual void releaseReservedIndexSpace() SK_OVERRIDE; 412 virtual void onSetVertexSourceToArray(const void* vertexArray, int vertexCount) SK_OVERRIDE; 413 virtual void onSetIndexSourceToArray(const void* indexArray, int indexCount) SK_OVERRIDE; 414 virtual void releaseVertexArray() SK_OVERRIDE; 415 virtual void releaseIndexArray() SK_OVERRIDE; 416 virtual void geometrySourceWillPush() SK_OVERRIDE; 417 virtual void geometrySourceWillPop(const GeometrySrcState& restoredState) SK_OVERRIDE; 418 419 420 // called when the 3D context state is unknown. Subclass should emit any 421 // assumed 3D context state and dirty any state cache. 422 virtual void onResetContext(uint32_t resetBits) = 0; 423 424 // overridden by backend-specific derived class to create objects. 425 virtual GrTexture* onCreateTexture(const GrTextureDesc& desc, 426 const void* srcData, 427 size_t rowBytes) = 0; 428 virtual GrTexture* onCreateCompressedTexture(const GrTextureDesc& desc, 429 const void* srcData) = 0; 430 virtual GrTexture* onWrapBackendTexture(const GrBackendTextureDesc&) = 0; 431 virtual GrRenderTarget* onWrapBackendRenderTarget(const GrBackendRenderTargetDesc&) = 0; 432 virtual GrVertexBuffer* onCreateVertexBuffer(size_t size, bool dynamic) = 0; 433 virtual GrIndexBuffer* onCreateIndexBuffer(size_t size, bool dynamic) = 0; 434 435 // overridden by backend-specific derived class to perform the clear and 436 // clearRect. NULL rect means clear whole target. If canIgnoreRect is 437 // true, it is okay to perform a full clear instead of a partial clear 438 virtual void onClear(GrRenderTarget*, const SkIRect* rect, GrColor color, 439 bool canIgnoreRect) = 0; 440 441 // overridden by backend-specific derived class to perform the draw call. 442 virtual void onGpuDraw(const DrawInfo&) = 0; 443 444 // overridden by backend-specific derived class to perform the read pixels. 445 virtual bool onReadPixels(GrRenderTarget* target, 446 int left, int top, int width, int height, 447 GrPixelConfig, 448 void* buffer, 449 size_t rowBytes) = 0; 450 451 // overridden by backend-specific derived class to perform the texture update 452 virtual bool onWriteTexturePixels(GrTexture* texture, 453 int left, int top, int width, int height, 454 GrPixelConfig config, const void* buffer, 455 size_t rowBytes) = 0; 456 457 // overridden by backend-specific derived class to perform the resolve 458 virtual void onResolveRenderTarget(GrRenderTarget* target) = 0; 459 460 // width and height may be larger than rt (if underlying API allows it). 461 // Should attach the SB to the RT. Returns false if compatible sb could 462 // not be created. 463 virtual bool createStencilBufferForRenderTarget(GrRenderTarget*, int width, int height) = 0; 464 465 // attaches an existing SB to an existing RT. 466 virtual bool attachStencilBufferToRenderTarget(GrStencilBuffer*, GrRenderTarget*) = 0; 467 468 // The GrGpu typically records the clients requested state and then flushes 469 // deltas from previous state at draw time. This function does the 470 // backend-specific flush of the state. 471 // returns false if current state is unsupported. 472 virtual bool flushGraphicsState(DrawType, const GrDeviceCoordTexture* dstCopy) = 0; 473 474 // clears target's entire stencil buffer to 0 475 virtual void clearStencil(GrRenderTarget* target) = 0; 476 477 // Given a rt, find or create a stencil buffer and attach it 478 bool attachStencilBufferToRenderTarget(GrRenderTarget* target); 479 480 // GrDrawTarget overrides 481 virtual void onDraw(const DrawInfo&) SK_OVERRIDE; 482 virtual void onStencilPath(const GrPath*, SkPath::FillType) SK_OVERRIDE; 483 virtual void onDrawPath(const GrPath*, SkPath::FillType, 484 const GrDeviceCoordTexture* dstCopy) SK_OVERRIDE; 485 virtual void onDrawPaths(const GrPathRange*, 486 const uint32_t indices[], int count, 487 const float transforms[], PathTransformType, 488 SkPath::FillType, const GrDeviceCoordTexture*) SK_OVERRIDE; 489 490 // readies the pools to provide vertex/index data. 491 void prepareVertexPool(); 492 void prepareIndexPool(); 493 494 void resetContext() { 495 // We call this because the client may have messed with the 496 // stencil buffer. Perhaps we should detect whether it is a 497 // internally created stencil buffer and if so skip the invalidate. 498 fClipMaskManager.invalidateStencilMask(); 499 this->onResetContext(fResetBits); 500 fResetBits = 0; 501 ++fResetTimestamp; 502 } 503 504 void handleDirtyContext() { 505 if (fResetBits) { 506 this->resetContext(); 507 } 508 } 509 510 enum { 511 kPreallocGeomPoolStateStackCnt = 4, 512 }; 513 SkSTArray<kPreallocGeomPoolStateStackCnt, GeometryPoolState, true> fGeomPoolStateStack; 514 ResetTimestamp fResetTimestamp; 515 uint32_t fResetBits; 516 GrVertexBufferAllocPool* fVertexPool; 517 GrIndexBufferAllocPool* fIndexPool; 518 // counts number of uses of vertex/index pool in the geometry stack 519 int fVertexPoolUseCnt; 520 int fIndexPoolUseCnt; 521 // these are mutable so they can be created on-demand 522 mutable GrIndexBuffer* fQuadIndexBuffer; 523 524 typedef GrDrawTarget INHERITED; 525}; 526 527#endif 528