1 2 /* 3 * Copyright 2010 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 11 #ifndef GrDrawTarget_DEFINED 12 #define GrDrawTarget_DEFINED 13 14 #include "GrClipData.h" 15 #include "GrDrawState.h" 16 #include "GrIndexBuffer.h" 17 #include "SkMatrix.h" 18 #include "GrRefCnt.h" 19 20 #include "SkClipStack.h" 21 #include "SkPath.h" 22 #include "SkTLazy.h" 23 #include "SkTArray.h" 24 #include "SkXfermode.h" 25 26 class GrClipData; 27 class GrPath; 28 class GrVertexBuffer; 29 class SkStrokeRec; 30 31 class GrDrawTarget : public GrRefCnt { 32 protected: 33 /** This helper class allows GrDrawTarget subclasses to set the caps values without having to be 34 made a friend of GrDrawTarget::Caps. */ 35 class CapsInternals { 36 public: 37 bool f8BitPaletteSupport : 1; 38 bool fNPOTTextureTileSupport : 1; 39 bool fTwoSidedStencilSupport : 1; 40 bool fStencilWrapOpsSupport : 1; 41 bool fHWAALineSupport : 1; 42 bool fShaderDerivativeSupport : 1; 43 bool fGeometryShaderSupport : 1; 44 bool fFSAASupport : 1; 45 bool fDualSourceBlendingSupport : 1; 46 bool fBufferLockSupport : 1; 47 bool fPathStencilingSupport : 1; 48 int fMaxRenderTargetSize; 49 int fMaxTextureSize; 50 }; 51 52 class DrawInfo; 53 54 public: 55 SK_DECLARE_INST_COUNT(GrDrawTarget) 56 57 /** 58 * Represents the draw target capabilities. 59 */ 60 class Caps { 61 public: 62 Caps() { memset(this, 0, sizeof(Caps)); } 63 Caps(const Caps& c) { *this = c; } 64 Caps& operator= (const Caps& c) { 65 memcpy(this, &c, sizeof(Caps)); 66 return *this; 67 } 68 void print() const; 69 70 bool eightBitPaletteSupport() const { return fInternals.f8BitPaletteSupport; } 71 bool npotTextureTileSupport() const { return fInternals.fNPOTTextureTileSupport; } 72 bool twoSidedStencilSupport() const { return fInternals.fTwoSidedStencilSupport; } 73 bool stencilWrapOpsSupport() const { return fInternals.fStencilWrapOpsSupport; } 74 bool hwAALineSupport() const { return fInternals.fHWAALineSupport; } 75 bool shaderDerivativeSupport() const { return fInternals.fShaderDerivativeSupport; } 76 bool geometryShaderSupport() const { return fInternals.fGeometryShaderSupport; } 77 bool fsaaSupport() const { return fInternals.fFSAASupport; } 78 bool dualSourceBlendingSupport() const { return fInternals.fDualSourceBlendingSupport; } 79 bool bufferLockSupport() const { return fInternals.fBufferLockSupport; } 80 bool pathStencilingSupport() const { return fInternals.fPathStencilingSupport; } 81 82 int maxRenderTargetSize() const { return fInternals.fMaxRenderTargetSize; } 83 int maxTextureSize() const { return fInternals.fMaxTextureSize; } 84 private: 85 CapsInternals fInternals; 86 friend class GrDrawTarget; // to set values of fInternals 87 }; 88 89 /////////////////////////////////////////////////////////////////////////// 90 91 GrDrawTarget(); 92 virtual ~GrDrawTarget(); 93 94 /** 95 * Gets the capabilities of the draw target. 96 */ 97 const Caps& getCaps() const { return fCaps; } 98 99 /** 100 * Sets the current clip to the region specified by clip. All draws will be 101 * clipped against this clip if kClip_StateBit is enabled. 102 * 103 * Setting the clip may (or may not) zero out the client's stencil bits. 104 * 105 * @param description of the clipping region 106 */ 107 void setClip(const GrClipData* clip); 108 109 /** 110 * Gets the current clip. 111 * 112 * @return the clip. 113 */ 114 const GrClipData* getClip() const; 115 116 /** 117 * Sets the draw state object for the draw target. Note that this does not 118 * make a copy. The GrDrawTarget will take a reference to passed object. 119 * Passing NULL will cause the GrDrawTarget to use its own internal draw 120 * state object rather than an externally provided one. 121 */ 122 void setDrawState(GrDrawState* drawState); 123 124 /** 125 * Read-only access to the GrDrawTarget's current draw state. 126 */ 127 const GrDrawState& getDrawState() const { return *fDrawState; } 128 129 /** 130 * Read-write access to the GrDrawTarget's current draw state. Note that 131 * this doesn't ref. 132 */ 133 GrDrawState* drawState() { return fDrawState; } 134 135 /** 136 * Color alpha and coverage are two inputs to the drawing pipeline. For some 137 * blend modes it is safe to fold the coverage into constant or per-vertex 138 * color alpha value. For other blend modes they must be handled separately. 139 * Depending on features available in the underlying 3D API this may or may 140 * not be possible. 141 * 142 * This function considers the current draw state and the draw target's 143 * capabilities to determine whether coverage can be handled correctly. The 144 * following assumptions are made: 145 * 1. The caller intends to somehow specify coverage. This can be 146 * specified either by enabling a coverage stage on the GrDrawState or 147 * via the vertex layout. 148 * 2. Other than enabling coverage stages, the current configuration of 149 * the target's GrDrawState is as it will be at draw time. 150 * 3. If a vertex source has not yet been specified then all stages with 151 * non-NULL textures will be referenced by the vertex layout. 152 */ 153 bool canApplyCoverage() const; 154 155 /** 156 * Determines whether incorporating partial pixel coverage into the constant 157 * color specified by setColor or per-vertex colors will give the right 158 * blending result. If a vertex source has not yet been specified then 159 * the function assumes that all stages with non-NULL textures will be 160 * referenced by the vertex layout. 161 */ 162 bool canTweakAlphaForCoverage() const; 163 164 /** 165 * Given the current draw state and hw support, will HW AA lines be used 166 * (if line primitive type is drawn)? If a vertex source has not yet been 167 * specified then the function assumes that all stages with non-NULL 168 * textures will be referenced by the vertex layout. 169 */ 170 bool willUseHWAALines() const; 171 172 /** 173 * There are three types of "sources" of geometry (vertices and indices) for 174 * draw calls made on the target. When performing an indexed draw, the 175 * indices and vertices can use different source types. Once a source is 176 * specified it can be used for multiple draws. However, the time at which 177 * the geometry data is no longer editable depends on the source type. 178 * 179 * Sometimes it is necessary to perform a draw while upstack code has 180 * already specified geometry that it isn't finished with. So there are push 181 * and pop methods. This allows the client to push the sources, draw 182 * something using alternate sources, and then pop to restore the original 183 * sources. 184 * 185 * Aside from pushes and pops, a source remains valid until another source 186 * is set or resetVertexSource / resetIndexSource is called. Drawing from 187 * a reset source is an error. 188 * 189 * The three types of sources are: 190 * 191 * 1. A cpu array (set*SourceToArray). This is useful when the caller 192 * already provided vertex data in a format compatible with a 193 * GrVertexLayout. The data in the array is consumed at the time that 194 * set*SourceToArray is called and subsequent edits to the array will not 195 * be reflected in draws. 196 * 197 * 2. Reserve. This is most useful when the caller has data it must 198 * transform before drawing and is not long-lived. The caller requests 199 * that the draw target make room for some amount of vertex and/or index 200 * data. The target provides ptrs to hold the vertex and/or index data. 201 * 202 * The data is writable up until the next drawIndexed, drawNonIndexed, 203 * drawIndexedInstances, or pushGeometrySource. At this point the data is 204 * frozen and the ptrs are no longer valid. 205 * 206 * Where the space is allocated and how it is uploaded to the GPU is 207 * subclass-dependent. 208 * 209 * 3. Vertex and Index Buffers. This is most useful for geometry that will 210 * is long-lived. When the data in the buffer is consumed depends on the 211 * GrDrawTarget subclass. For deferred subclasses the caller has to 212 * guarantee that the data is still available in the buffers at playback. 213 * (TODO: Make this more automatic as we have done for read/write pixels) 214 */ 215 216 /** 217 * Reserves space for vertices and/or indices. Zero can be specifed as 218 * either the vertex or index count if the caller desires to only reserve 219 * space for only indices or only vertices. If zero is specifed for 220 * vertexCount then the vertex source will be unmodified and likewise for 221 * indexCount. 222 * 223 * If the function returns true then the reserve suceeded and the vertices 224 * and indices pointers will point to the space created. 225 * 226 * If the target cannot make space for the request then this function will 227 * return false. If vertexCount was non-zero then upon failure the vertex 228 * source is reset and likewise for indexCount. 229 * 230 * The pointers to the space allocated for vertices and indices remain valid 231 * until a drawIndexed, drawNonIndexed, drawIndexedInstances, or push/ 232 * popGeomtrySource is called. At that point logically a snapshot of the 233 * data is made and the pointers are invalid. 234 * 235 * @param vertexLayout the format of vertices (ignored if vertexCount == 0). 236 * @param vertexCount the number of vertices to reserve space for. Can be 237 * 0. 238 * @param indexCount the number of indices to reserve space for. Can be 0. 239 * @param vertices will point to reserved vertex space if vertexCount is 240 * non-zero. Illegal to pass NULL if vertexCount > 0. 241 * @param indices will point to reserved index space if indexCount is 242 * non-zero. Illegal to pass NULL if indexCount > 0. 243 */ 244 bool reserveVertexAndIndexSpace(GrVertexLayout vertexLayout, 245 int vertexCount, 246 int indexCount, 247 void** vertices, 248 void** indices); 249 250 /** 251 * Provides hints to caller about the number of vertices and indices 252 * that can be allocated cheaply. This can be useful if caller is reserving 253 * space but doesn't know exactly how much geometry is needed. 254 * 255 * Also may hint whether the draw target should be flushed first. This is 256 * useful for deferred targets. 257 * 258 * @param vertexSize size of vertices caller would like to reserve 259 * @param vertexCount in: hint about how many vertices the caller would 260 * like to allocate. 261 * out: a hint about the number of vertices that can be 262 * allocated cheaply. Negative means no hint. 263 * Ignored if NULL. 264 * @param indexCount in: hint about how many indices the caller would 265 * like to allocate. 266 * out: a hint about the number of indices that can be 267 * allocated cheaply. Negative means no hint. 268 * Ignored if NULL. 269 * 270 * @return true if target should be flushed based on the input values. 271 */ 272 virtual bool geometryHints(size_t vertexSize, 273 int* vertexCount, 274 int* indexCount) const; 275 276 /** 277 * Sets source of vertex data for the next draw. Array must contain 278 * the vertex data when this is called. 279 * 280 * @param array cpu array containing vertex data. 281 * @param size size of the vertex data. 282 * @param vertexCount the number of vertices in the array. 283 */ 284 void setVertexSourceToArray(GrVertexLayout vertexLayout, 285 const void* vertexArray, 286 int vertexCount); 287 288 /** 289 * Sets source of index data for the next indexed draw. Array must contain 290 * the indices when this is called. 291 * 292 * @param array cpu array containing index data. 293 * @param indexCount the number of indices in the array. 294 */ 295 void setIndexSourceToArray(const void* indexArray, int indexCount); 296 297 /** 298 * Sets source of vertex data for the next draw. Data does not have to be 299 * in the buffer until drawIndexed, drawNonIndexed, or drawIndexedInstances. 300 * 301 * @param buffer vertex buffer containing vertex data. Must be 302 * unlocked before draw call. 303 * @param vertexLayout layout of the vertex data in the buffer. 304 */ 305 void setVertexSourceToBuffer(GrVertexLayout vertexLayout, 306 const GrVertexBuffer* buffer); 307 308 /** 309 * Sets source of index data for the next indexed draw. Data does not have 310 * to be in the buffer until drawIndexed. 311 * 312 * @param buffer index buffer containing indices. Must be unlocked 313 * before indexed draw call. 314 */ 315 void setIndexSourceToBuffer(const GrIndexBuffer* buffer); 316 317 /** 318 * Resets vertex source. Drawing from reset vertices is illegal. Set vertex 319 * source to reserved, array, or buffer before next draw. May be able to free 320 * up temporary storage allocated by setVertexSourceToArray or 321 * reserveVertexSpace. 322 */ 323 void resetVertexSource(); 324 325 /** 326 * Resets index source. Indexed Drawing from reset indices is illegal. Set 327 * index source to reserved, array, or buffer before next indexed draw. May 328 * be able to free up temporary storage allocated by setIndexSourceToArray 329 * or reserveIndexSpace. 330 */ 331 void resetIndexSource(); 332 333 /** 334 * Query to find out if the vertex or index source is reserved. 335 */ 336 bool hasReservedVerticesOrIndices() const { 337 return kReserved_GeometrySrcType == this->getGeomSrc().fVertexSrc || 338 kReserved_GeometrySrcType == this->getGeomSrc().fIndexSrc; 339 } 340 341 /** 342 * Pushes and resets the vertex/index sources. Any reserved vertex / index 343 * data is finalized (i.e. cannot be updated after the matching pop but can 344 * be drawn from). Must be balanced by a pop. 345 */ 346 void pushGeometrySource(); 347 348 /** 349 * Pops the vertex / index sources from the matching push. 350 */ 351 void popGeometrySource(); 352 353 /** 354 * Draws indexed geometry using the current state and current vertex / index 355 * sources. 356 * 357 * @param type The type of primitives to draw. 358 * @param startVertex the vertex in the vertex array/buffer corresponding 359 * to index 0 360 * @param startIndex first index to read from index src. 361 * @param vertexCount one greater than the max index. 362 * @param indexCount the number of index elements to read. The index count 363 * is effectively trimmed to the last completely 364 * specified primitive. 365 * @param devBounds optional bounds hint. This is a promise from the caller, 366 * not a request for clipping. 367 */ 368 void drawIndexed(GrPrimitiveType type, 369 int startVertex, 370 int startIndex, 371 int vertexCount, 372 int indexCount, 373 const SkRect* devBounds = NULL); 374 375 /** 376 * Draws non-indexed geometry using the current state and current vertex 377 * sources. 378 * 379 * @param type The type of primitives to draw. 380 * @param startVertex the vertex in the vertex array/buffer corresponding 381 * to index 0 382 * @param vertexCount one greater than the max index. 383 * @param devBounds optional bounds hint. This is a promise from the caller, 384 * not a request for clipping. 385 */ 386 void drawNonIndexed(GrPrimitiveType type, 387 int startVertex, 388 int vertexCount, 389 const SkRect* devBounds = NULL); 390 391 /** 392 * Draws path into the stencil buffer. The fill must be either even/odd or 393 * winding (not inverse or hairline). It will respect the HW antialias flag 394 * on the draw state (if possible in the 3D API). 395 */ 396 void stencilPath(const GrPath*, const SkStrokeRec& stroke, SkPath::FillType fill); 397 398 /** 399 * Helper function for drawing rects. This does not use the current index 400 * and vertex sources. After returning, the vertex and index sources may 401 * have changed. They should be reestablished before the next drawIndexed 402 * or drawNonIndexed. This cannot be called between reserving and releasing 403 * geometry. 404 * 405 * A subclass may override this to perform more optimal rect rendering. Its 406 * draws should be funneled through one of the public GrDrawTarget draw methods 407 * (e.g. drawNonIndexed, drawIndexedInstances, ...). The base class draws a two 408 * triangle fan using drawNonIndexed from reserved vertex space. 409 * 410 * @param rect the rect to draw 411 * @param matrix optional matrix applied to rect (before viewMatrix) 412 * @param srcRects specifies rects for stages enabled by stageEnableMask. 413 * if stageEnableMask bit i is 1, srcRects is not NULL, 414 * and srcRects[i] is not NULL, then srcRects[i] will be 415 * used as coordinates for stage i. Otherwise, if stage i 416 * is enabled then rect is used as the coordinates. 417 * @param srcMatrices optional matrices applied to srcRects. If 418 * srcRect[i] is non-NULL and srcMatrices[i] is 419 * non-NULL then srcRect[i] will be transformed by 420 * srcMatrix[i]. srcMatrices can be NULL when no 421 * srcMatrices are desired. 422 */ 423 virtual void drawRect(const GrRect& rect, 424 const SkMatrix* matrix, 425 const GrRect* srcRects[], 426 const SkMatrix* srcMatrices[]); 427 /** 428 * Helper for drawRect when the caller doesn't need separate src rects or 429 * matrices. 430 */ 431 void drawSimpleRect(const GrRect& rect, const SkMatrix* matrix = NULL) { 432 drawRect(rect, matrix, NULL, NULL); 433 } 434 void drawSimpleRect(const GrIRect& irect, const SkMatrix* matrix = NULL) { 435 SkRect rect = SkRect::MakeFromIRect(irect); 436 this->drawRect(rect, matrix, NULL, NULL); 437 } 438 439 /** 440 * This call is used to draw multiple instances of some geometry with a 441 * given number of vertices (V) and indices (I) per-instance. The indices in 442 * the index source must have the form i[k+I] == i[k] + V. Also, all indices 443 * i[kI] ... i[(k+1)I-1] must be elements of the range kV ... (k+1)V-1. As a 444 * concrete example, the following index buffer for drawing a series of 445 * quads each as two triangles each satisfies these conditions with V=4 and 446 * I=6: 447 * (0,1,2,0,2,3, 4,5,6,4,6,7, 8,9,10,8,10,11, ...) 448 * 449 * The call assumes that the pattern of indices fills the entire index 450 * source. The size of the index buffer limits the number of instances that 451 * can be drawn by the GPU in a single draw. However, the caller may specify 452 * any (positive) number for instanceCount and if necessary multiple GPU 453 * draws will be issued. Moreover, when drawIndexedInstances is called 454 * multiple times it may be possible for GrDrawTarget to group them into a 455 * single GPU draw. 456 * 457 * @param type the type of primitives to draw 458 * @param instanceCount the number of instances to draw. Each instance 459 * consists of verticesPerInstance vertices indexed by 460 * indicesPerInstance indices drawn as the primitive 461 * type specified by type. 462 * @param verticesPerInstance The number of vertices in each instance (V 463 * in the above description). 464 * @param indicesPerInstance The number of indices in each instance (I 465 * in the above description). 466 * @param devBounds optional bounds hint. This is a promise from the caller, 467 * not a request for clipping. 468 */ 469 void drawIndexedInstances(GrPrimitiveType type, 470 int instanceCount, 471 int verticesPerInstance, 472 int indicesPerInstance, 473 const SkRect* devBounds = NULL); 474 475 /** 476 * Clear the current render target if one isn't passed in. Ignores the 477 * clip and all other draw state (blend mode, stages, etc). Clears the 478 * whole thing if rect is NULL, otherwise just the rect. 479 */ 480 virtual void clear(const GrIRect* rect, 481 GrColor color, 482 GrRenderTarget* renderTarget = NULL) = 0; 483 484 /** 485 * Release any resources that are cached but not currently in use. This 486 * is intended to give an application some recourse when resources are low. 487 */ 488 virtual void purgeResources() {}; 489 490 /** 491 * For subclass internal use to invoke a call to onDraw(). See DrawInfo below. 492 */ 493 void executeDraw(const DrawInfo& info) { this->onDraw(info); } 494 495 //////////////////////////////////////////////////////////////////////////// 496 497 /** 498 * See AutoStateRestore below. 499 */ 500 enum ASRInit { 501 kPreserve_ASRInit, 502 kReset_ASRInit 503 }; 504 505 /** 506 * Saves off the current state and restores it in the destructor. It will 507 * install a new GrDrawState object on the target (setDrawState) and restore 508 * the previous one in the destructor. The caller should call drawState() to 509 * get the new draw state after the ASR is installed. 510 * 511 * GrDrawState* state = target->drawState(); 512 * AutoStateRestore asr(target, GrDrawTarget::kReset_ASRInit). 513 * state->setRenderTarget(rt); // state refers to the GrDrawState set on 514 * // target before asr was initialized. 515 * // Therefore, rt is set on the GrDrawState 516 * // that will be restored after asr's 517 * // destructor rather than target's current 518 * // GrDrawState. 519 */ 520 class AutoStateRestore : ::GrNoncopyable { 521 public: 522 /** 523 * Default ASR will have no effect unless set() is subsequently called. 524 */ 525 AutoStateRestore(); 526 527 /** 528 * Saves the state on target. The state will be restored when the ASR 529 * is destroyed. If this constructor is used do not call set(). 530 * 531 * @param init Should the newly installed GrDrawState be a copy of the 532 * previous state or a default-initialized GrDrawState. 533 */ 534 AutoStateRestore(GrDrawTarget* target, ASRInit init); 535 536 ~AutoStateRestore(); 537 538 /** 539 * Saves the state on target. The state will be restored when the ASR 540 * is destroyed. This should only be called once per ASR object and only 541 * when the default constructor was used. For nested saves use multiple 542 * ASR objects. 543 * 544 * @param init Should the newly installed GrDrawState be a copy of the 545 * previous state or a default-initialized GrDrawState. 546 */ 547 void set(GrDrawTarget* target, ASRInit init); 548 549 private: 550 GrDrawTarget* fDrawTarget; 551 SkTLazy<GrDrawState> fTempState; 552 GrDrawState* fSavedState; 553 }; 554 555 //////////////////////////////////////////////////////////////////////////// 556 557 class AutoReleaseGeometry : ::GrNoncopyable { 558 public: 559 AutoReleaseGeometry(GrDrawTarget* target, 560 GrVertexLayout vertexLayout, 561 int vertexCount, 562 int indexCount); 563 AutoReleaseGeometry(); 564 ~AutoReleaseGeometry(); 565 bool set(GrDrawTarget* target, 566 GrVertexLayout vertexLayout, 567 int vertexCount, 568 int indexCount); 569 bool succeeded() const { return NULL != fTarget; } 570 void* vertices() const { GrAssert(this->succeeded()); return fVertices; } 571 void* indices() const { GrAssert(this->succeeded()); return fIndices; } 572 GrPoint* positions() const { 573 return static_cast<GrPoint*>(this->vertices()); 574 } 575 576 private: 577 void reset(); 578 579 GrDrawTarget* fTarget; 580 void* fVertices; 581 void* fIndices; 582 }; 583 584 //////////////////////////////////////////////////////////////////////////// 585 586 class AutoClipRestore : ::GrNoncopyable { 587 public: 588 AutoClipRestore(GrDrawTarget* target) { 589 fTarget = target; 590 fClip = fTarget->getClip(); 591 } 592 593 AutoClipRestore(GrDrawTarget* target, const SkIRect& newClip); 594 595 ~AutoClipRestore() { 596 fTarget->setClip(fClip); 597 } 598 private: 599 GrDrawTarget* fTarget; 600 const GrClipData* fClip; 601 SkTLazy<SkClipStack> fStack; 602 GrClipData fReplacementClip; 603 }; 604 605 //////////////////////////////////////////////////////////////////////////// 606 607 class AutoGeometryPush : ::GrNoncopyable { 608 public: 609 AutoGeometryPush(GrDrawTarget* target) { 610 GrAssert(NULL != target); 611 fTarget = target; 612 target->pushGeometrySource(); 613 } 614 ~AutoGeometryPush() { 615 fTarget->popGeometrySource(); 616 } 617 private: 618 GrDrawTarget* fTarget; 619 }; 620 621 protected: 622 623 /** 624 * Optimizations for blending / coverage to be applied based on the current 625 * state. 626 * Subclasses that actually draw (as opposed to those that just buffer for 627 * playback) must implement the flags that replace the output color. 628 */ 629 enum BlendOptFlags { 630 /** 631 * No optimization 632 */ 633 kNone_BlendOpt = 0, 634 /** 635 * Don't draw at all 636 */ 637 kSkipDraw_BlendOptFlag = 0x2, 638 /** 639 * Emit the src color, disable HW blending (replace dst with src) 640 */ 641 kDisableBlend_BlendOptFlag = 0x4, 642 /** 643 * The coverage value does not have to be computed separately from 644 * alpha, the the output color can be the modulation of the two. 645 */ 646 kCoverageAsAlpha_BlendOptFlag = 0x1, 647 /** 648 * Instead of emitting a src color, emit coverage in the alpha channel 649 * and r,g,b are "don't cares". 650 */ 651 kEmitCoverage_BlendOptFlag = 0x10, 652 /** 653 * Emit transparent black instead of the src color, no need to compute 654 * coverage. 655 */ 656 kEmitTransBlack_BlendOptFlag = 0x8, 657 }; 658 GR_DECL_BITFIELD_OPS_FRIENDS(BlendOptFlags); 659 660 /** 661 * Determines what optimizations can be applied based on the blend. The coefficients may have 662 * to be tweaked in order for the optimization to work. srcCoeff and dstCoeff are optional 663 * params that receive the tweaked coefficients. Normally the function looks at the current 664 * state to see if coverage is enabled. By setting forceCoverage the caller can speculatively 665 * determine the blend optimizations that would be used if there was partial pixel coverage. 666 */ 667 BlendOptFlags getBlendOpts(bool forceCoverage = false, 668 GrBlendCoeff* srcCoeff = NULL, 669 GrBlendCoeff* dstCoeff = NULL) const; 670 671 enum GeometrySrcType { 672 kNone_GeometrySrcType, //<! src has not been specified 673 kReserved_GeometrySrcType, //<! src was set using reserve*Space 674 kArray_GeometrySrcType, //<! src was set using set*SourceToArray 675 kBuffer_GeometrySrcType //<! src was set using set*SourceToBuffer 676 }; 677 678 struct GeometrySrcState { 679 GeometrySrcType fVertexSrc; 680 union { 681 // valid if src type is buffer 682 const GrVertexBuffer* fVertexBuffer; 683 // valid if src type is reserved or array 684 int fVertexCount; 685 }; 686 687 GeometrySrcType fIndexSrc; 688 union { 689 // valid if src type is buffer 690 const GrIndexBuffer* fIndexBuffer; 691 // valid if src type is reserved or array 692 int fIndexCount; 693 }; 694 695 GrVertexLayout fVertexLayout; 696 }; 697 698 int indexCountInCurrentSource() const { 699 const GeometrySrcState& src = this->getGeomSrc(); 700 switch (src.fIndexSrc) { 701 case kNone_GeometrySrcType: 702 return 0; 703 case kReserved_GeometrySrcType: 704 case kArray_GeometrySrcType: 705 return src.fIndexCount; 706 case kBuffer_GeometrySrcType: 707 return src.fIndexBuffer->sizeInBytes() / sizeof(uint16_t); 708 default: 709 GrCrash("Unexpected Index Source."); 710 return 0; 711 } 712 } 713 714 // allows derived class to set the caps 715 CapsInternals* capsInternals() { return &fCaps.fInternals; } 716 717 // A subclass may override this function if it wishes to be notified when the clip is changed. 718 // The override should call INHERITED::clipWillBeSet(). 719 virtual void clipWillBeSet(const GrClipData* clipData); 720 721 // subclasses must call this in their destructors to ensure all vertex 722 // and index sources have been released (including those held by 723 // pushGeometrySource()) 724 void releaseGeometry(); 725 726 // accessors for derived classes 727 const GeometrySrcState& getGeomSrc() const { return fGeoSrcStateStack.back(); } 728 // it is preferable to call this rather than getGeomSrc()->fVertexLayout because of the assert. 729 GrVertexLayout getVertexLayout() const { 730 // the vertex layout is only valid if a vertex source has been specified. 731 GrAssert(this->getGeomSrc().fVertexSrc != kNone_GeometrySrcType); 732 return this->getGeomSrc().fVertexLayout; 733 } 734 735 Caps fCaps; 736 737 /** 738 * Used to communicate draws to subclass's onDraw function. 739 */ 740 class DrawInfo { 741 public: 742 DrawInfo(const DrawInfo& di) { (*this) = di; } 743 DrawInfo& operator =(const DrawInfo& di); 744 745 GrPrimitiveType primitiveType() const { return fPrimitiveType; } 746 int startVertex() const { return fStartVertex; } 747 int startIndex() const { return fStartIndex; } 748 int vertexCount() const { return fVertexCount; } 749 int indexCount() const { return fIndexCount; } 750 int verticesPerInstance() const { return fVerticesPerInstance; } 751 int indicesPerInstance() const { return fIndicesPerInstance; } 752 int instanceCount() const { return fInstanceCount; } 753 754 bool isIndexed() const { return fIndexCount > 0; } 755 #if GR_DEBUG 756 bool isInstanced() const; // this version is longer because of asserts 757 #else 758 bool isInstanced() const { return fInstanceCount > 0; } 759 #endif 760 761 // adds or remove instances 762 void adjustInstanceCount(int instanceOffset); 763 // shifts the start vertex 764 void adjustStartVertex(int vertexOffset); 765 // shifts the start index 766 void adjustStartIndex(int indexOffset); 767 768 void setDevBounds(const SkRect& bounds) { 769 fDevBoundsStorage = bounds; 770 fDevBounds = &fDevBoundsStorage; 771 } 772 const SkRect* getDevBounds() const { return fDevBounds; } 773 774 private: 775 DrawInfo() { fDevBounds = NULL; } 776 777 friend class GrDrawTarget; 778 779 GrPrimitiveType fPrimitiveType; 780 781 int fStartVertex; 782 int fStartIndex; 783 int fVertexCount; 784 int fIndexCount; 785 786 int fInstanceCount; 787 int fVerticesPerInstance; 788 int fIndicesPerInstance; 789 790 SkRect fDevBoundsStorage; 791 SkRect* fDevBounds; 792 }; 793 794 private: 795 // A subclass can optionally overload this function to be notified before 796 // vertex and index space is reserved. 797 virtual void willReserveVertexAndIndexSpace(size_t vertexSize, int vertexCount, int indexCount) {} 798 799 // implemented by subclass to allocate space for reserved geom 800 virtual bool onReserveVertexSpace(size_t vertexSize, int vertexCount, void** vertices) = 0; 801 virtual bool onReserveIndexSpace(int indexCount, void** indices) = 0; 802 // implemented by subclass to handle release of reserved geom space 803 virtual void releaseReservedVertexSpace() = 0; 804 virtual void releaseReservedIndexSpace() = 0; 805 // subclass must consume array contents when set 806 virtual void onSetVertexSourceToArray(const void* vertexArray, int vertexCount) = 0; 807 virtual void onSetIndexSourceToArray(const void* indexArray, int indexCount) = 0; 808 // subclass is notified that geom source will be set away from an array 809 virtual void releaseVertexArray() = 0; 810 virtual void releaseIndexArray() = 0; 811 // subclass overrides to be notified just before geo src state is pushed/popped. 812 virtual void geometrySourceWillPush() = 0; 813 virtual void geometrySourceWillPop(const GeometrySrcState& restoredState) = 0; 814 // subclass called to perform drawing 815 virtual void onDraw(const DrawInfo&) = 0; 816 virtual void onStencilPath(const GrPath*, const SkStrokeRec& stroke, SkPath::FillType fill) = 0; 817 818 // helpers for reserving vertex and index space. 819 bool reserveVertexSpace(GrVertexLayout vertexLayout, 820 int vertexCount, 821 void** vertices); 822 bool reserveIndexSpace(int indexCount, void** indices); 823 824 // called by drawIndexed and drawNonIndexed. Use a negative indexCount to 825 // indicate non-indexed drawing. 826 bool checkDraw(GrPrimitiveType type, int startVertex, 827 int startIndex, int vertexCount, 828 int indexCount) const; 829 // called when setting a new vert/idx source to unref prev vb/ib 830 void releasePreviousVertexSource(); 831 void releasePreviousIndexSource(); 832 833 enum { 834 kPreallocGeoSrcStateStackCnt = 4, 835 }; 836 SkSTArray<kPreallocGeoSrcStateStackCnt, GeometrySrcState, true> fGeoSrcStateStack; 837 const GrClipData* fClip; 838 GrDrawState* fDrawState; 839 GrDrawState fDefaultDrawState; 840 841 typedef GrRefCnt INHERITED; 842 }; 843 844 GR_MAKE_BITFIELD_OPS(GrDrawTarget::BlendOptFlags); 845 846 #endif 847
