GrGpu.h revision b8eb2e89edf914caf5479baeffcb670d3e93f496
1 2/* 3 * Copyright 2011 Google Inc. 4 * 5 * Use of this source code is governed by a BSD-style license that can be 6 * found in the LICENSE file. 7 */ 8 9 10#ifndef GrGpu_DEFINED 11#define GrGpu_DEFINED 12 13#include "GrDrawTarget.h" 14#include "GrRect.h" 15#include "GrRefCnt.h" 16#include "GrClipMaskManager.h" 17 18#include "SkPath.h" 19 20class GrContext; 21class GrIndexBufferAllocPool; 22class GrPath; 23class GrPathRenderer; 24class GrPathRendererChain; 25class GrResource; 26class GrStencilBuffer; 27class GrVertexBufferAllocPool; 28 29class GrGpu : public GrDrawTarget { 30 31public: 32 33 /** 34 * Additional blend coefficients for dual source blending, not exposed 35 * through GrPaint/GrContext. 36 */ 37 enum ExtendedBlendCoeffs { 38 // source 2 refers to second output color when 39 // using dual source blending. 40 kS2C_GrBlendCoeff = kPublicGrBlendCoeffCount, 41 kIS2C_GrBlendCoeff, 42 kS2A_GrBlendCoeff, 43 kIS2A_GrBlendCoeff, 44 45 kTotalGrBlendCoeffCount 46 }; 47 48 /** 49 * Create an instance of GrGpu that matches the specified backend. If the requested backend is 50 * not supported (at compile-time or run-time) this returns NULL. The context will not be 51 * fully constructed and should not be used by GrGpu until after this function returns. 52 */ 53 static GrGpu* Create(GrBackend, GrBackendContext, GrContext* context); 54 55 //////////////////////////////////////////////////////////////////////////// 56 57 GrGpu(GrContext* context); 58 virtual ~GrGpu(); 59 60 GrContext* getContext() { return this->INHERITED::getContext(); } 61 const GrContext* getContext() const { return this->INHERITED::getContext(); } 62 63 /** 64 * The GrGpu object normally assumes that no outsider is setting state 65 * within the underlying 3D API's context/device/whatever. This call informs 66 * the GrGpu that the state was modified and it shouldn't make assumptions 67 * about the state. 68 */ 69 void markContextDirty() { fContextIsDirty = true; } 70 71 void unimpl(const char[]); 72 73 /** 74 * Creates a texture object. If desc width or height is not a power of 75 * two but underlying API requires a power of two texture then srcData 76 * will be embedded in a power of two texture. The extra width and height 77 * is filled as though srcData were rendered clamped into the texture. 78 * 79 * If kRenderTarget_TextureFlag is specified the GrRenderTarget is 80 * accessible via GrTexture::asRenderTarget(). The texture will hold a ref 81 * on the render target until its releaseRenderTarget() is called or it is 82 * destroyed. 83 * 84 * @param desc describes the texture to be created. 85 * @param srcData texel data to load texture. Begins with full-size 86 * palette data for paletted textures. Contains width* 87 * height texels. If NULL texture data is uninitialized. 88 * 89 * @return The texture object if successful, otherwise NULL. 90 */ 91 GrTexture* createTexture(const GrTextureDesc& desc, 92 const void* srcData, size_t rowBytes); 93 94 /** 95 * Implements GrContext::wrapBackendTexture 96 */ 97 GrTexture* wrapBackendTexture(const GrBackendTextureDesc&); 98 99 /** 100 * Implements GrContext::wrapBackendTexture 101 */ 102 GrRenderTarget* wrapBackendRenderTarget(const GrBackendRenderTargetDesc&); 103 104 /** 105 * Creates a vertex buffer. 106 * 107 * @param size size in bytes of the vertex buffer 108 * @param dynamic hints whether the data will be frequently changed 109 * by either GrVertexBuffer::lock or 110 * GrVertexBuffer::updateData. 111 * 112 * @return The vertex buffer if successful, otherwise NULL. 113 */ 114 GrVertexBuffer* createVertexBuffer(uint32_t size, bool dynamic); 115 116 /** 117 * Creates an index buffer. 118 * 119 * @param size size in bytes of the index buffer 120 * @param dynamic hints whether the data will be frequently changed 121 * by either GrIndexBuffer::lock or 122 * GrIndexBuffer::updateData. 123 * 124 * @return The index buffer if successful, otherwise NULL. 125 */ 126 GrIndexBuffer* createIndexBuffer(uint32_t size, bool dynamic); 127 128 /** 129 * Creates a path object that can be stenciled using stencilPath(). It is 130 * only legal to call this if the caps report support for path stenciling. 131 */ 132 GrPath* createPath(const SkPath& path); 133 134 /** 135 * Returns an index buffer that can be used to render quads. 136 * Six indices per quad: 0, 1, 2, 0, 2, 3, etc. 137 * The max number of quads can be queried using GrIndexBuffer::maxQuads(). 138 * Draw with kTriangles_GrPrimitiveType 139 * @ return the quad index buffer 140 */ 141 const GrIndexBuffer* getQuadIndexBuffer() const; 142 143 /** 144 * Returns a vertex buffer with four position-only vertices [(0,0), (1,0), 145 * (1,1), (0,1)]. 146 * @ return unit square vertex buffer 147 */ 148 const GrVertexBuffer* getUnitSquareVertexBuffer() const; 149 150 /** 151 * Resolves MSAA. 152 */ 153 void resolveRenderTarget(GrRenderTarget* target); 154 155 /** 156 * Ensures that the current render target is actually set in the 157 * underlying 3D API. Used when client wants to use 3D API to directly 158 * render to the RT. 159 */ 160 void forceRenderTargetFlush(); 161 162 /** 163 * Gets a preferred 8888 config to use for writing / reading pixel data. The returned config 164 * must have at least as many bits per channel as the config param. 165 */ 166 virtual GrPixelConfig preferredReadPixelsConfig(GrPixelConfig config) const { return config; } 167 virtual GrPixelConfig preferredWritePixelsConfig(GrPixelConfig config) const { return config; } 168 169 /** 170 * Called before uploading writing pixels to a GrTexture when the src pixel config doesn't 171 * match the texture's config. 172 */ 173 virtual bool canWriteTexturePixels(const GrTexture*, GrPixelConfig srcConfig) const = 0; 174 175 /** 176 * OpenGL's readPixels returns the result bottom-to-top while the skia 177 * API is top-to-bottom. Thus we have to do a y-axis flip. The obvious 178 * solution is to have the subclass do the flip using either the CPU or GPU. 179 * However, the caller (GrContext) may have transformations to apply and can 180 * simply fold in the y-flip for free. On the other hand, the subclass may 181 * be able to do it for free itself. For example, the subclass may have to 182 * do memcpys to handle rowBytes that aren't tight. It could do the y-flip 183 * concurrently. 184 * 185 * This function returns true if a y-flip is required to put the pixels in 186 * top-to-bottom order and the subclass cannot do it for free. 187 * 188 * See read pixels for the params 189 * @return true if calling readPixels with the same set of params will 190 * produce bottom-to-top data 191 */ 192 virtual bool readPixelsWillPayForYFlip(GrRenderTarget* renderTarget, 193 int left, int top, 194 int width, int height, 195 GrPixelConfig config, 196 size_t rowBytes) const = 0; 197 /** 198 * This should return true if reading a NxM rectangle of pixels from a 199 * render target is faster if the target has dimensons N and M and the read 200 * rectangle has its top-left at 0,0. 201 */ 202 virtual bool fullReadPixelsIsFasterThanPartial() const { return false; }; 203 204 /** 205 * Reads a rectangle of pixels from a render target. 206 * 207 * @param renderTarget the render target to read from. NULL means the 208 * current render target. 209 * @param left left edge of the rectangle to read (inclusive) 210 * @param top top edge of the rectangle to read (inclusive) 211 * @param width width of rectangle to read in pixels. 212 * @param height height of rectangle to read in pixels. 213 * @param config the pixel config of the destination buffer 214 * @param buffer memory to read the rectangle into. 215 * @param rowBytes the number of bytes between consecutive rows. Zero 216 * means rows are tightly packed. 217 * @param invertY buffer should be populated bottom-to-top as opposed 218 * to top-to-bottom (skia's usual order) 219 * 220 * @return true if the read succeeded, false if not. The read can fail 221 * because of a unsupported pixel config or because no render 222 * target is currently set. 223 */ 224 bool readPixels(GrRenderTarget* renderTarget, 225 int left, int top, int width, int height, 226 GrPixelConfig config, void* buffer, size_t rowBytes); 227 228 /** 229 * Updates the pixels in a rectangle of a texture. 230 * 231 * @param left left edge of the rectangle to write (inclusive) 232 * @param top top edge of the rectangle to write (inclusive) 233 * @param width width of rectangle to write in pixels. 234 * @param height height of rectangle to write in pixels. 235 * @param config the pixel config of the source buffer 236 * @param buffer memory to read pixels from 237 * @param rowBytes number of bytes between consecutive rows. Zero 238 * means rows are tightly packed. 239 */ 240 bool writeTexturePixels(GrTexture* texture, 241 int left, int top, int width, int height, 242 GrPixelConfig config, const void* buffer, 243 size_t rowBytes); 244 245 /** 246 * Called to tell Gpu object that all GrResources have been lost and should 247 * be abandoned. Overrides must call INHERITED::abandonResources(). 248 */ 249 virtual void abandonResources(); 250 251 /** 252 * Called to tell Gpu object to release all GrResources. Overrides must call 253 * INHERITED::releaseResources(). 254 */ 255 void releaseResources(); 256 257 /** 258 * Add resource to list of resources. Should only be called by GrResource. 259 * @param resource the resource to add. 260 */ 261 void insertResource(GrResource* resource); 262 263 /** 264 * Remove resource from list of resources. Should only be called by 265 * GrResource. 266 * @param resource the resource to remove. 267 */ 268 void removeResource(GrResource* resource); 269 270 // GrDrawTarget overrides 271 virtual void clear(const GrIRect* rect, 272 GrColor color, 273 GrRenderTarget* renderTarget = NULL) SK_OVERRIDE; 274 275 virtual void purgeResources() SK_OVERRIDE { 276 // The clip mask manager can rebuild all its clip masks so just 277 // get rid of them all. 278 fClipMaskManager.releaseResources(); 279 } 280 281 // After the client interacts directly with the 3D context state the GrGpu 282 // must resync its internal state and assumptions about 3D context state. 283 // Each time this occurs the GrGpu bumps a timestamp. 284 // state of the 3D context 285 // At 10 resets / frame and 60fps a 64bit timestamp will overflow in about 286 // a billion years. 287 typedef uint64_t ResetTimestamp; 288 289 // This timestamp is always older than the current timestamp 290 static const ResetTimestamp kExpiredTimestamp = 0; 291 // Returns a timestamp based on the number of times the context was reset. 292 // This timestamp can be used to lazily detect when cached 3D context state 293 // is dirty. 294 ResetTimestamp getResetTimestamp() const { 295 return fResetTimestamp; 296 } 297 298 /** 299 * Can the provided configuration act as a color render target? 300 */ 301 bool isConfigRenderable(GrPixelConfig config) const { 302 GrAssert(kGrPixelConfigCnt > config); 303 return fConfigRenderSupport[config]; 304 } 305 306 /** 307 * These methods are called by the clip manager's setupClipping function 308 * which (called as part of GrGpu's implementation of onDraw and 309 * onStencilPath member functions.) The GrGpu subclass should flush the 310 * stencil state to the 3D API in its implementation of flushGraphicsState. 311 */ 312 void enableScissor(const GrIRect& rect) { 313 fScissorState.fEnabled = true; 314 fScissorState.fRect = rect; 315 } 316 void disableScissor() { fScissorState.fEnabled = false; } 317 318 /** 319 * Like the scissor methods above this is called by setupClipping and 320 * should be flushed by the GrGpu subclass in flushGraphicsState. These 321 * stencil settings should be used in place of those on the GrDrawState. 322 * They have been adjusted to account for any interactions between the 323 * GrDrawState's stencil settings and stencil clipping. 324 */ 325 void setStencilSettings(const GrStencilSettings& settings) { 326 fStencilSettings = settings; 327 } 328 void disableStencil() { fStencilSettings.setDisabled(); } 329 330 // GrGpu subclass sets clip bit in the stencil buffer. The subclass is 331 // free to clear the remaining bits to zero if masked clears are more 332 // expensive than clearing all bits. 333 virtual void clearStencilClip(const GrIRect& rect, bool insideClip) = 0; 334 335 enum PrivateDrawStateStateBits { 336 kFirstBit = (GrDrawState::kLastPublicStateBit << 1), 337 338 kModifyStencilClip_StateBit = kFirstBit, // allows draws to modify 339 // stencil bits used for 340 // clipping. 341 }; 342 343protected: 344 enum DrawType { 345 kDrawPoints_DrawType, 346 kDrawLines_DrawType, 347 kDrawTriangles_DrawType, 348 kStencilPath_DrawType, 349 }; 350 351 DrawType PrimTypeToDrawType(GrPrimitiveType type) { 352 switch (type) { 353 case kTriangles_GrPrimitiveType: 354 case kTriangleStrip_GrPrimitiveType: 355 case kTriangleFan_GrPrimitiveType: 356 return kDrawTriangles_DrawType; 357 case kPoints_GrPrimitiveType: 358 return kDrawPoints_DrawType; 359 case kLines_GrPrimitiveType: 360 case kLineStrip_GrPrimitiveType: 361 return kDrawLines_DrawType; 362 default: 363 GrCrash("Unexpected primitive type"); 364 return kDrawTriangles_DrawType; 365 } 366 } 367 368 // prepares clip flushes gpu state before a draw 369 bool setupClipAndFlushState(DrawType); 370 371 // Functions used to map clip-respecting stencil tests into normal 372 // stencil funcs supported by GPUs. 373 static GrStencilFunc ConvertStencilFunc(bool stencilInClip, 374 GrStencilFunc func); 375 static void ConvertStencilFuncAndMask(GrStencilFunc func, 376 bool clipInStencil, 377 unsigned int clipBit, 378 unsigned int userBits, 379 unsigned int* ref, 380 unsigned int* mask); 381 382 GrClipMaskManager fClipMaskManager; 383 384 struct GeometryPoolState { 385 const GrVertexBuffer* fPoolVertexBuffer; 386 int fPoolStartVertex; 387 388 const GrIndexBuffer* fPoolIndexBuffer; 389 int fPoolStartIndex; 390 }; 391 const GeometryPoolState& getGeomPoolState() { 392 return fGeomPoolStateStack.back(); 393 } 394 395 // The state of the scissor is controlled by the clip manager 396 struct ScissorState { 397 bool fEnabled; 398 GrIRect fRect; 399 } fScissorState; 400 401 // The final stencil settings to use as determined by the clip manager. 402 GrStencilSettings fStencilSettings; 403 404 // Derived classes need access to this so they can fill it out in their 405 // constructors 406 bool fConfigRenderSupport[kGrPixelConfigCnt]; 407 408 // Helpers for setting up geometry state 409 void finalizeReservedVertices(); 410 void finalizeReservedIndices(); 411 412private: 413 // GrDrawTarget overrides 414 virtual bool onReserveVertexSpace(size_t vertexSize, int vertexCount, void** vertices) SK_OVERRIDE; 415 virtual bool onReserveIndexSpace(int indexCount, void** indices) SK_OVERRIDE; 416 virtual void releaseReservedVertexSpace() SK_OVERRIDE; 417 virtual void releaseReservedIndexSpace() SK_OVERRIDE; 418 virtual void onSetVertexSourceToArray(const void* vertexArray, int vertexCount) SK_OVERRIDE; 419 virtual void onSetIndexSourceToArray(const void* indexArray, int indexCount) SK_OVERRIDE; 420 virtual void releaseVertexArray() SK_OVERRIDE; 421 virtual void releaseIndexArray() SK_OVERRIDE; 422 virtual void geometrySourceWillPush() SK_OVERRIDE; 423 virtual void geometrySourceWillPop(const GeometrySrcState& restoredState) SK_OVERRIDE; 424 425 426 // called when the 3D context state is unknown. Subclass should emit any 427 // assumed 3D context state and dirty any state cache. 428 virtual void onResetContext() = 0; 429 430 // overridden by backend-specific derived class to create objects. 431 virtual GrTexture* onCreateTexture(const GrTextureDesc& desc, 432 const void* srcData, 433 size_t rowBytes) = 0; 434 virtual GrTexture* onWrapBackendTexture(const GrBackendTextureDesc&) = 0; 435 virtual GrRenderTarget* onWrapBackendRenderTarget(const GrBackendRenderTargetDesc&) = 0; 436 virtual GrVertexBuffer* onCreateVertexBuffer(uint32_t size, bool dynamic) = 0; 437 virtual GrIndexBuffer* onCreateIndexBuffer(uint32_t size, bool dynamic) = 0; 438 virtual GrPath* onCreatePath(const SkPath& path) = 0; 439 440 // overridden by backend-specific derived class to perform the clear and 441 // clearRect. NULL rect means clear whole target. 442 virtual void onClear(const GrIRect* rect, GrColor color) = 0; 443 444 // overridden by backend-specific derived class to perform the draw call. 445 virtual void onGpuDraw(const DrawInfo&) = 0; 446 // when GrDrawTarget::stencilPath is called the draw state's current stencil 447 // settings are ignored. Instead the GrGpu decides the stencil rules 448 // necessary to stencil the path. These are still subject to filtering by 449 // the clip mask manager. 450 virtual void setStencilPathSettings(const GrPath&, 451 SkPath::FillType, 452 GrStencilSettings* settings) = 0; 453 // overridden by backend-specific derived class to perform the path stenciling. 454 virtual void onGpuStencilPath(const GrPath*, SkPath::FillType) = 0; 455 456 // overridden by backend-specific derived class to perform flush 457 virtual void onForceRenderTargetFlush() = 0; 458 459 // overridden by backend-specific derived class to perform the read pixels. 460 virtual bool onReadPixels(GrRenderTarget* target, 461 int left, int top, int width, int height, 462 GrPixelConfig, 463 void* buffer, 464 size_t rowBytes) = 0; 465 466 // overridden by backend-specific derived class to perform the texture update 467 virtual bool onWriteTexturePixels(GrTexture* texture, 468 int left, int top, int width, int height, 469 GrPixelConfig config, const void* buffer, 470 size_t rowBytes) = 0; 471 472 // overridden by backend-specific derived class to perform the resolve 473 virtual void onResolveRenderTarget(GrRenderTarget* target) = 0; 474 475 // width and height may be larger than rt (if underlying API allows it). 476 // Should attach the SB to the RT. Returns false if compatible sb could 477 // not be created. 478 virtual bool createStencilBufferForRenderTarget(GrRenderTarget*, int width, int height) = 0; 479 480 // attaches an existing SB to an existing RT. 481 virtual bool attachStencilBufferToRenderTarget(GrStencilBuffer*, GrRenderTarget*) = 0; 482 483 // The GrGpu typically records the clients requested state and then flushes 484 // deltas from previous state at draw time. This function does the 485 // backend-specific flush of the state 486 // returns false if current state is unsupported. 487 virtual bool flushGraphicsState(DrawType) = 0; 488 489 // clears the entire stencil buffer to 0 490 virtual void clearStencil() = 0; 491 492 // Given a rt, find or create a stencil buffer and attach it 493 bool attachStencilBufferToRenderTarget(GrRenderTarget* target); 494 495 // GrDrawTarget overrides 496 virtual void onDraw(const DrawInfo&) SK_OVERRIDE; 497 virtual void onStencilPath(const GrPath* path, const SkStrokeRec& stroke, 498 SkPath::FillType) SK_OVERRIDE; 499 500 // readies the pools to provide vertex/index data. 501 void prepareVertexPool(); 502 void prepareIndexPool(); 503 504 void resetContext() { 505 // We call this because the client may have messed with the 506 // stencil buffer. Perhaps we should detect whether it is a 507 // internally created stencil buffer and if so skip the invalidate. 508 fClipMaskManager.invalidateStencilMask(); 509 this->onResetContext(); 510 ++fResetTimestamp; 511 } 512 513 void handleDirtyContext() { 514 if (fContextIsDirty) { 515 this->resetContext(); 516 fContextIsDirty = false; 517 } 518 } 519 520 enum { 521 kPreallocGeomPoolStateStackCnt = 4, 522 }; 523 typedef SkTInternalLList<GrResource> ResourceList; 524 SkSTArray<kPreallocGeomPoolStateStackCnt, GeometryPoolState, true> fGeomPoolStateStack; 525 ResetTimestamp fResetTimestamp; 526 GrVertexBufferAllocPool* fVertexPool; 527 GrIndexBufferAllocPool* fIndexPool; 528 // counts number of uses of vertex/index pool in the geometry stack 529 int fVertexPoolUseCnt; 530 int fIndexPoolUseCnt; 531 // these are mutable so they can be created on-demand 532 mutable GrVertexBuffer* fUnitSquareVertexBuffer; 533 mutable GrIndexBuffer* fQuadIndexBuffer; 534 bool fContextIsDirty; 535 ResourceList fResourceList; 536 537 typedef GrDrawTarget INHERITED; 538}; 539 540#endif 541