GrGpu.h revision 56ce48ade325f6f49acb0da31d6252806e4ed7ef
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 "SkPath.h" 14 15class GrContext; 16class GrIndexBufferAllocPool; 17class GrPath; 18class GrPathRenderer; 19class GrPathRendererChain; 20class GrResource; 21class GrStencilBuffer; 22class GrVertexBufferAllocPool; 23 24class GrGpu : public GrDrawTarget { 25public: 26 27 /** 28 * Additional blend coefficients for dual source blending, not exposed 29 * through GrPaint/GrContext. 30 */ 31 enum ExtendedBlendCoeffs { 32 // source 2 refers to second output color when 33 // using dual source blending. 34 kS2C_GrBlendCoeff = kPublicGrBlendCoeffCount, 35 kIS2C_GrBlendCoeff, 36 kS2A_GrBlendCoeff, 37 kIS2A_GrBlendCoeff, 38 39 kTotalGrBlendCoeffCount 40 }; 41 42 /** 43 * Create an instance of GrGpu that matches the specified backend. If the requested backend is 44 * not supported (at compile-time or run-time) this returns NULL. The context will not be 45 * fully constructed and should not be used by GrGpu until after this function returns. 46 */ 47 static GrGpu* Create(GrBackend, GrBackendContext, GrContext* context); 48 49 //////////////////////////////////////////////////////////////////////////// 50 51 GrGpu(GrContext* context); 52 virtual ~GrGpu(); 53 54 GrContext* getContext() { return this->INHERITED::getContext(); } 55 const GrContext* getContext() const { return this->INHERITED::getContext(); } 56 57 /** 58 * The GrGpu object normally assumes that no outsider is setting state 59 * within the underlying 3D API's context/device/whatever. This call informs 60 * the GrGpu that the state was modified and it shouldn't make assumptions 61 * about the state. 62 */ 63 void markContextDirty(uint32_t state = kAll_GrBackendState) { 64 fResetBits |= state; 65 } 66 67 void unimpl(const char[]); 68 69 /** 70 * Creates a texture object. If desc width or height is not a power of 71 * two but underlying API requires a power of two texture then srcData 72 * will be embedded in a power of two texture. The extra width and height 73 * is filled as though srcData were rendered clamped into the texture. 74 * 75 * If kRenderTarget_TextureFlag is specified the GrRenderTarget is 76 * accessible via GrTexture::asRenderTarget(). The texture will hold a ref 77 * on the render target until the texture is destroyed. 78 * 79 * @param desc describes the texture to be created. 80 * @param srcData texel data to load texture. Begins with full-size 81 * palette data for paletted textures. Contains width* 82 * height texels. If NULL texture data is uninitialized. 83 * 84 * @return The texture object if successful, otherwise NULL. 85 */ 86 GrTexture* createTexture(const GrTextureDesc& desc, 87 const void* srcData, size_t rowBytes); 88 89 /** 90 * Implements GrContext::wrapBackendTexture 91 */ 92 GrTexture* wrapBackendTexture(const GrBackendTextureDesc&); 93 94 /** 95 * Implements GrContext::wrapBackendTexture 96 */ 97 GrRenderTarget* wrapBackendRenderTarget(const GrBackendRenderTargetDesc&); 98 99 /** 100 * Creates a vertex buffer. 101 * 102 * @param size size in bytes of the vertex buffer 103 * @param dynamic hints whether the data will be frequently changed 104 * by either GrVertexBuffer::lock or 105 * GrVertexBuffer::updateData. 106 * 107 * @return The vertex buffer if successful, otherwise NULL. 108 */ 109 GrVertexBuffer* createVertexBuffer(size_t size, bool dynamic); 110 111 /** 112 * Creates an index buffer. 113 * 114 * @param size size in bytes of the index buffer 115 * @param dynamic hints whether the data will be frequently changed 116 * by either GrIndexBuffer::lock or 117 * GrIndexBuffer::updateData. 118 * 119 * @return The index buffer if successful, otherwise NULL. 120 */ 121 GrIndexBuffer* createIndexBuffer(size_t size, bool dynamic); 122 123 /** 124 * Creates a path object that can be stenciled using stencilPath(). It is 125 * only legal to call this if the caps report support for path stenciling. 126 */ 127 GrPath* createPath(const SkPath& path, const SkStrokeRec& stroke); 128 129 /** 130 * Returns an index buffer that can be used to render quads. 131 * Six indices per quad: 0, 1, 2, 0, 2, 3, etc. 132 * The max number of quads can be queried using GrIndexBuffer::maxQuads(). 133 * Draw with kTriangles_GrPrimitiveType 134 * @ return the quad index buffer 135 */ 136 const GrIndexBuffer* getQuadIndexBuffer() const; 137 138 /** 139 * Resolves MSAA. 140 */ 141 void resolveRenderTarget(GrRenderTarget* target); 142 143 /** 144 * Ensures that the current render target is actually set in the 145 * underlying 3D API. Used when client wants to use 3D API to directly 146 * render to the RT. 147 */ 148 void forceRenderTargetFlush(); 149 150 /** 151 * Gets a preferred 8888 config to use for writing/reading pixel data to/from a surface with 152 * config surfaceConfig. The returned config must have at least as many bits per channel as the 153 * readConfig or writeConfig param. 154 */ 155 virtual GrPixelConfig preferredReadPixelsConfig(GrPixelConfig readConfig, 156 GrPixelConfig surfaceConfig) const { 157 return readConfig; 158 } 159 virtual GrPixelConfig preferredWritePixelsConfig(GrPixelConfig writeConfig, 160 GrPixelConfig surfaceConfig) const { 161 return writeConfig; 162 } 163 164 /** 165 * Called before uploading writing pixels to a GrTexture when the src pixel config doesn't 166 * match the texture's config. 167 */ 168 virtual bool canWriteTexturePixels(const GrTexture*, GrPixelConfig srcConfig) const = 0; 169 170 /** 171 * OpenGL's readPixels returns the result bottom-to-top while the skia 172 * API is top-to-bottom. Thus we have to do a y-axis flip. The obvious 173 * solution is to have the subclass do the flip using either the CPU or GPU. 174 * However, the caller (GrContext) may have transformations to apply and can 175 * simply fold in the y-flip for free. On the other hand, the subclass may 176 * be able to do it for free itself. For example, the subclass may have to 177 * do memcpys to handle rowBytes that aren't tight. It could do the y-flip 178 * concurrently. 179 * 180 * This function returns true if a y-flip is required to put the pixels in 181 * top-to-bottom order and the subclass cannot do it for free. 182 * 183 * See read pixels for the params 184 * @return true if calling readPixels with the same set of params will 185 * produce bottom-to-top data 186 */ 187 virtual bool readPixelsWillPayForYFlip(GrRenderTarget* renderTarget, 188 int left, int top, 189 int width, int height, 190 GrPixelConfig config, 191 size_t rowBytes) const = 0; 192 /** 193 * This should return true if reading a NxM rectangle of pixels from a 194 * render target is faster if the target has dimensons N and M and the read 195 * rectangle has its top-left at 0,0. 196 */ 197 virtual bool fullReadPixelsIsFasterThanPartial() const { return false; }; 198 199 /** 200 * Reads a rectangle of pixels from a render target. 201 * 202 * @param renderTarget the render target to read from. NULL means the 203 * current render target. 204 * @param left left edge of the rectangle to read (inclusive) 205 * @param top top edge of the rectangle to read (inclusive) 206 * @param width width of rectangle to read in pixels. 207 * @param height height of rectangle to read in pixels. 208 * @param config the pixel config of the destination buffer 209 * @param buffer memory to read the rectangle into. 210 * @param rowBytes the number of bytes between consecutive rows. Zero 211 * means rows are tightly packed. 212 * @param invertY buffer should be populated bottom-to-top as opposed 213 * to top-to-bottom (skia's usual order) 214 * 215 * @return true if the read succeeded, false if not. The read can fail 216 * because of a unsupported pixel config or because no render 217 * target is currently set. 218 */ 219 bool readPixels(GrRenderTarget* renderTarget, 220 int left, int top, int width, int height, 221 GrPixelConfig config, void* buffer, size_t rowBytes); 222 223 /** 224 * Updates the pixels in a rectangle of a texture. 225 * 226 * @param left left edge of the rectangle to write (inclusive) 227 * @param top top edge of the rectangle to write (inclusive) 228 * @param width width of rectangle to write in pixels. 229 * @param height height of rectangle to write in pixels. 230 * @param config the pixel config of the source buffer 231 * @param buffer memory to read pixels from 232 * @param rowBytes number of bytes between consecutive rows. Zero 233 * means rows are tightly packed. 234 */ 235 bool writeTexturePixels(GrTexture* texture, 236 int left, int top, int width, int height, 237 GrPixelConfig config, const void* buffer, 238 size_t rowBytes); 239 240 /** 241 * Called to tell Gpu object that all GrResources have been lost and should 242 * be abandoned. Overrides must call INHERITED::abandonResources(). 243 */ 244 virtual void abandonResources(); 245 246 /** 247 * Called to tell Gpu object to release all GrResources. Overrides must call 248 * INHERITED::releaseResources(). 249 */ 250 void releaseResources(); 251 252 /** 253 * Add resource to list of resources. Should only be called by GrResource. 254 * @param resource the resource to add. 255 */ 256 void insertResource(GrResource* resource); 257 258 /** 259 * Remove resource from list of resources. Should only be called by 260 * GrResource. 261 * @param resource the resource to remove. 262 */ 263 void removeResource(GrResource* resource); 264 265 // GrDrawTarget overrides 266 virtual void clear(const SkIRect* rect, 267 GrColor color, 268 bool canIgnoreRect, 269 GrRenderTarget* renderTarget = NULL) SK_OVERRIDE; 270 271 virtual void purgeResources() SK_OVERRIDE { 272 // The clip mask manager can rebuild all its clip masks so just 273 // get rid of them all. 274 fClipMaskManager.releaseResources(); 275 } 276 277 // After the client interacts directly with the 3D context state the GrGpu 278 // must resync its internal state and assumptions about 3D context state. 279 // Each time this occurs the GrGpu bumps a timestamp. 280 // state of the 3D context 281 // At 10 resets / frame and 60fps a 64bit timestamp will overflow in about 282 // a billion years. 283 typedef uint64_t ResetTimestamp; 284 285 // This timestamp is always older than the current timestamp 286 static const ResetTimestamp kExpiredTimestamp = 0; 287 // Returns a timestamp based on the number of times the context was reset. 288 // This timestamp can be used to lazily detect when cached 3D context state 289 // is dirty. 290 ResetTimestamp getResetTimestamp() const { 291 return fResetTimestamp; 292 } 293 294 /** 295 * These methods are called by the clip manager's setupClipping function 296 * which (called as part of GrGpu's implementation of onDraw and 297 * onStencilPath member functions.) The GrGpu subclass should flush the 298 * stencil state to the 3D API in its implementation of flushGraphicsState. 299 */ 300 void enableScissor(const SkIRect& rect) { 301 fScissorState.fEnabled = true; 302 fScissorState.fRect = rect; 303 } 304 void disableScissor() { fScissorState.fEnabled = false; } 305 306 /** 307 * Like the scissor methods above this is called by setupClipping and 308 * should be flushed by the GrGpu subclass in flushGraphicsState. These 309 * stencil settings should be used in place of those on the GrDrawState. 310 * They have been adjusted to account for any interactions between the 311 * GrDrawState's stencil settings and stencil clipping. 312 */ 313 void setStencilSettings(const GrStencilSettings& settings) { 314 fStencilSettings = settings; 315 } 316 void disableStencil() { fStencilSettings.setDisabled(); } 317 318 // GrGpu subclass sets clip bit in the stencil buffer. The subclass is 319 // free to clear the remaining bits to zero if masked clears are more 320 // expensive than clearing all bits. 321 virtual void clearStencilClip(const SkIRect& rect, bool insideClip) = 0; 322 323 enum PrivateDrawStateStateBits { 324 kFirstBit = (GrDrawState::kLastPublicStateBit << 1), 325 326 kModifyStencilClip_StateBit = kFirstBit, // allows draws to modify 327 // stencil bits used for 328 // clipping. 329 }; 330 331 void getPathStencilSettingsForFillType(SkPath::FillType fill, GrStencilSettings* outStencilSettings); 332 333protected: 334 enum DrawType { 335 kDrawPoints_DrawType, 336 kDrawLines_DrawType, 337 kDrawTriangles_DrawType, 338 kStencilPath_DrawType, 339 kDrawPath_DrawType, 340 }; 341 342 DrawType PrimTypeToDrawType(GrPrimitiveType type) { 343 switch (type) { 344 case kTriangles_GrPrimitiveType: 345 case kTriangleStrip_GrPrimitiveType: 346 case kTriangleFan_GrPrimitiveType: 347 return kDrawTriangles_DrawType; 348 case kPoints_GrPrimitiveType: 349 return kDrawPoints_DrawType; 350 case kLines_GrPrimitiveType: 351 case kLineStrip_GrPrimitiveType: 352 return kDrawLines_DrawType; 353 default: 354 GrCrash("Unexpected primitive type"); 355 return kDrawTriangles_DrawType; 356 } 357 } 358 359 // prepares clip flushes gpu state before a draw 360 bool setupClipAndFlushState(DrawType, 361 const GrDeviceCoordTexture* dstCopy, 362 GrDrawState::AutoRestoreEffects* are); 363 364 // Functions used to map clip-respecting stencil tests into normal 365 // stencil funcs supported by GPUs. 366 static GrStencilFunc ConvertStencilFunc(bool stencilInClip, 367 GrStencilFunc func); 368 static void ConvertStencilFuncAndMask(GrStencilFunc func, 369 bool clipInStencil, 370 unsigned int clipBit, 371 unsigned int userBits, 372 unsigned int* ref, 373 unsigned int* mask); 374 375 GrClipMaskManager fClipMaskManager; 376 377 struct GeometryPoolState { 378 const GrVertexBuffer* fPoolVertexBuffer; 379 int fPoolStartVertex; 380 381 const GrIndexBuffer* fPoolIndexBuffer; 382 int fPoolStartIndex; 383 }; 384 const GeometryPoolState& getGeomPoolState() { 385 return fGeomPoolStateStack.back(); 386 } 387 388 // The state of the scissor is controlled by the clip manager 389 struct ScissorState { 390 bool fEnabled; 391 SkIRect fRect; 392 } fScissorState; 393 394 // The final stencil settings to use as determined by the clip manager. 395 GrStencilSettings fStencilSettings; 396 397 // Helpers for setting up geometry state 398 void finalizeReservedVertices(); 399 void finalizeReservedIndices(); 400 401private: 402 // GrDrawTarget overrides 403 virtual bool onReserveVertexSpace(size_t vertexSize, int vertexCount, void** vertices) SK_OVERRIDE; 404 virtual bool onReserveIndexSpace(int indexCount, void** indices) SK_OVERRIDE; 405 virtual void releaseReservedVertexSpace() SK_OVERRIDE; 406 virtual void releaseReservedIndexSpace() SK_OVERRIDE; 407 virtual void onSetVertexSourceToArray(const void* vertexArray, int vertexCount) SK_OVERRIDE; 408 virtual void onSetIndexSourceToArray(const void* indexArray, int indexCount) SK_OVERRIDE; 409 virtual void releaseVertexArray() SK_OVERRIDE; 410 virtual void releaseIndexArray() SK_OVERRIDE; 411 virtual void geometrySourceWillPush() SK_OVERRIDE; 412 virtual void geometrySourceWillPop(const GeometrySrcState& restoredState) SK_OVERRIDE; 413 414 415 // called when the 3D context state is unknown. Subclass should emit any 416 // assumed 3D context state and dirty any state cache. 417 virtual void onResetContext(uint32_t resetBits) = 0; 418 419 // overridden by backend-specific derived class to create objects. 420 virtual GrTexture* onCreateTexture(const GrTextureDesc& desc, 421 const void* srcData, 422 size_t rowBytes) = 0; 423 virtual GrTexture* onWrapBackendTexture(const GrBackendTextureDesc&) = 0; 424 virtual GrRenderTarget* onWrapBackendRenderTarget(const GrBackendRenderTargetDesc&) = 0; 425 virtual GrVertexBuffer* onCreateVertexBuffer(size_t size, bool dynamic) = 0; 426 virtual GrIndexBuffer* onCreateIndexBuffer(size_t size, bool dynamic) = 0; 427 virtual GrPath* onCreatePath(const SkPath& path, const SkStrokeRec&) = 0; 428 429 // overridden by backend-specific derived class to perform the clear and 430 // clearRect. NULL rect means clear whole target. If canIgnoreRect is 431 // true, it is okay to perform a full clear instead of a partial clear 432 virtual void onClear(const SkIRect* rect, GrColor color, bool canIgnoreRect) = 0; 433 434 // overridden by backend-specific derived class to perform the draw call. 435 virtual void onGpuDraw(const DrawInfo&) = 0; 436 437 // overridden by backend-specific derived class to perform the path stenciling. 438 virtual void onGpuStencilPath(const GrPath*, SkPath::FillType) = 0; 439 virtual void onGpuDrawPath(const GrPath*, SkPath::FillType) = 0; 440 441 // overridden by backend-specific derived class to perform flush 442 virtual void onForceRenderTargetFlush() = 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 the entire stencil buffer to 0 475 virtual void clearStencil() = 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; 485 486 // readies the pools to provide vertex/index data. 487 void prepareVertexPool(); 488 void prepareIndexPool(); 489 490 void resetContext() { 491 // We call this because the client may have messed with the 492 // stencil buffer. Perhaps we should detect whether it is a 493 // internally created stencil buffer and if so skip the invalidate. 494 fClipMaskManager.invalidateStencilMask(); 495 this->onResetContext(fResetBits); 496 fResetBits = 0; 497 ++fResetTimestamp; 498 } 499 500 void handleDirtyContext() { 501 if (fResetBits) { 502 this->resetContext(); 503 } 504 } 505 506 enum { 507 kPreallocGeomPoolStateStackCnt = 4, 508 }; 509 typedef SkTInternalLList<GrResource> ResourceList; 510 SkSTArray<kPreallocGeomPoolStateStackCnt, GeometryPoolState, true> fGeomPoolStateStack; 511 ResetTimestamp fResetTimestamp; 512 uint32_t fResetBits; 513 GrVertexBufferAllocPool* fVertexPool; 514 GrIndexBufferAllocPool* fIndexPool; 515 // counts number of uses of vertex/index pool in the geometry stack 516 int fVertexPoolUseCnt; 517 int fIndexPoolUseCnt; 518 // these are mutable so they can be created on-demand 519 mutable GrIndexBuffer* fQuadIndexBuffer; 520 // Used to abandon/release all resources created by this GrGpu. TODO: Move this 521 // functionality to GrResourceCache. 522 ResourceList fResourceList; 523 524 typedef GrDrawTarget INHERITED; 525}; 526 527#endif 528