Make GPU coord transforms automatic

src/gpu/gl/GrGLEffectMatrix.cpp

-/*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "GrGLEffectMatrix.h"
-#include "GrDrawEffect.h"
-#include "GrTexture.h"
-
-GrGLEffect::EffectKey GrGLEffectMatrix::GenKey(const SkMatrix& effectMatrix,
-                                               const GrDrawEffect& drawEffect,
-                                               CoordsType coordsType,
-                                               const GrTexture* texture) {
-    EffectKey key = 0;
-    SkMatrix::TypeMask type0 = effectMatrix.getType();
-    SkMatrix::TypeMask type1;
-    if (GrEffect::kLocal_CoordsType == coordsType) {
-        type1 = drawEffect.getCoordChangeMatrix().getType();
-    } else {
-        if (drawEffect.programHasExplicitLocalCoords()) {
-            // We only make the key indicate that device coords are referenced when the local coords
-            // are not actually determined by positions.
-            key |= kPositionCoords_Flag;
-        }
-        type1 = SkMatrix::kIdentity_Mask;
-    }
-
-    int combinedTypes = type0 | type1;
-
-    bool reverseY = (NULL != texture) && kBottomLeft_GrSurfaceOrigin == texture->origin();
-
-    if (SkMatrix::kPerspective_Mask & combinedTypes) {
-        key |= kGeneral_MatrixType;
-    } else if (((SkMatrix::kAffine_Mask | SkMatrix::kScale_Mask) & combinedTypes) || reverseY) {
-        key |= kNoPersp_MatrixType;
-    } else if (SkMatrix::kTranslate_Mask & combinedTypes) {
-        key |= kTrans_MatrixType;
-    } else {
-        key |= kIdentity_MatrixType;
-    }
-    return key;
-}
-
-GrSLType GrGLEffectMatrix::emitCode(GrGLShaderBuilder* builder,
-                                    EffectKey key,
-                                    SkString* fsCoordName,
-                                    SkString* vsCoordName,
-                                    const char* suffix) {
-    GrGLShaderBuilder::VertexBuilder* vertexBuilder = builder->getVertexBuilder();
-    SkASSERT(NULL != vertexBuilder);
-
-    GrSLType varyingType = kVoid_GrSLType;
-    const char* uniName;
-    key &= kKeyMask;
-    switch (key & kMatrixTypeKeyMask) {
-        case kIdentity_MatrixType:
-            fUniType = kVoid_GrSLType;
-            uniName = NULL;
-            varyingType = kVec2f_GrSLType;
-            break;
-        case kTrans_MatrixType:
-            fUniType = kVec2f_GrSLType;
-            uniName = "StageTranslate";
-            varyingType = kVec2f_GrSLType;
-            break;
-        case kNoPersp_MatrixType:
-            fUniType = kMat33f_GrSLType;
-            uniName = "StageMatrix";
-            varyingType = kVec2f_GrSLType;
-            break;
-        case kGeneral_MatrixType:
-            fUniType = kMat33f_GrSLType;
-            uniName = "StageMatrix";
-            varyingType = kVec3f_GrSLType;
-            break;
-        default:
-            GrCrash("Unexpected key.");
-    }
-    SkString suffixedUniName;
-    if (kVoid_GrSLType != fUniType) {
-        if (NULL != suffix) {
-            suffixedUniName.append(uniName);
-            suffixedUniName.append(suffix);
-            uniName = suffixedUniName.c_str();
-        }
-        fUni = builder->addUniform(GrGLShaderBuilder::kVertex_Visibility,
-                                   fUniType,
-                                   uniName,
-                                   &uniName);
-    }
-
-    const char* varyingName = "MatrixCoord";
-    SkString suffixedVaryingName;
-    if (NULL != suffix) {
-        suffixedVaryingName.append(varyingName);
-        suffixedVaryingName.append(suffix);
-        varyingName = suffixedVaryingName.c_str();
-    }
-    const char* vsVaryingName;
-    const char* fsVaryingName;
-    vertexBuilder->addVarying(varyingType, varyingName, &vsVaryingName, &fsVaryingName);
-
-    const GrGLShaderVar* coords;
-    switch (fCoordsType) {
-        case GrEffect::kLocal_CoordsType:
-            SkASSERT(!(kPositionCoords_Flag & key));
-            coords = &vertexBuilder->localCoordsAttribute();
-            break;
-        case GrEffect::kPosition_CoordsType:
-            SkASSERT((kPositionCoords_Flag & key) || !vertexBuilder->hasExplicitLocalCoords());
-            coords = &vertexBuilder->positionAttribute();
-            break;
-        default:
-            coords = NULL; // prevents warning
-            GrCrash("Unexpected coords type.");
-    }
-    // varying = matrix * coords (logically)
-    switch (fUniType) {
-        case kVoid_GrSLType:
-            SkASSERT(kVec2f_GrSLType == varyingType);
-            vertexBuilder->vsCodeAppendf("\t%s = %s;\n", vsVaryingName, coords->c_str());
-            break;
-        case kVec2f_GrSLType:
-            SkASSERT(kVec2f_GrSLType == varyingType);
-            vertexBuilder->vsCodeAppendf("\t%s = %s + %s;\n",
-                                         vsVaryingName, uniName, coords->c_str());
-            break;
-        case kMat33f_GrSLType: {
-            SkASSERT(kVec2f_GrSLType == varyingType || kVec3f_GrSLType == varyingType);
-            if (kVec2f_GrSLType == varyingType) {
-                vertexBuilder->vsCodeAppendf("\t%s = (%s * vec3(%s, 1)).xy;\n",
-                                             vsVaryingName, uniName, coords->c_str());
-            } else {
-                vertexBuilder->vsCodeAppendf("\t%s = %s * vec3(%s, 1);\n",
-                                             vsVaryingName, uniName, coords->c_str());
-            }
-            break;
-        }
-        default:
-            GrCrash("Unexpected uniform type.");
-    }
-    if (NULL != vsCoordName) {
-        *vsCoordName = vsVaryingName;
-    }
-    if (NULL != fsCoordName) {
-        *fsCoordName = fsVaryingName;
-    }
-    return varyingType;
-}
-
-/**
-    * This is similar to emitCode except that it performs perspective division in the FS if the
-    * texture coordinates have a w coordinate. The fsCoordName always refers to a vec2f.
-    */
-void GrGLEffectMatrix::emitCodeMakeFSCoords2D(GrGLShaderBuilder* builder,
-                                              EffectKey key,
-                                              SkString* fsCoordName,
-                                              SkString* vsVaryingName,
-                                              GrSLType* vsVaryingType,
-                                              const char* suffix) {
-    SkString fsVaryingName;
-
-    GrSLType varyingType = this->emitCode(builder,
-                                          key,
-                                          &fsVaryingName,
-                                          vsVaryingName,
-                                          suffix);
-    if (kVec3f_GrSLType == varyingType) {
-
-        const char* coordName = "coords2D";
-        SkString suffixedCoordName;
-        if (NULL != suffix) {
-            suffixedCoordName.append(coordName);
-            suffixedCoordName.append(suffix);
-            coordName = suffixedCoordName.c_str();
-        }
-        builder->fsCodeAppendf("\tvec2 %s = %s.xy / %s.z;",
-                               coordName, fsVaryingName.c_str(), fsVaryingName.c_str());
-        if (NULL != fsCoordName) {
-            *fsCoordName = coordName;
-        }
-    } else if(NULL != fsCoordName) {
-        *fsCoordName = fsVaryingName;
-    }
-    if (NULL != vsVaryingType) {
-        *vsVaryingType = varyingType;
-    }
-}
-
-void GrGLEffectMatrix::setData(const GrGLUniformManager& uniformManager,
-                               const SkMatrix& matrix,
-                               const GrDrawEffect& drawEffect,
-                               const GrTexture* texture) {
-    SkASSERT(fUni.isValid() != (kVoid_GrSLType == fUniType));
-    const SkMatrix& coordChangeMatrix = GrEffect::kLocal_CoordsType == fCoordsType ?
-                                            drawEffect.getCoordChangeMatrix() :
-                                            SkMatrix::I();
-    switch (fUniType) {
-        case kVoid_GrSLType:
-            SkASSERT(matrix.isIdentity());
-            SkASSERT(coordChangeMatrix.isIdentity());
-            SkASSERT(NULL == texture || kTopLeft_GrSurfaceOrigin == texture->origin());
-            return;
-        case kVec2f_GrSLType: {
-            SkASSERT(SkMatrix::kTranslate_Mask == (matrix.getType() | coordChangeMatrix.getType()));
-            SkASSERT(NULL == texture || kTopLeft_GrSurfaceOrigin == texture->origin());
-            SkScalar tx = matrix[SkMatrix::kMTransX] + (coordChangeMatrix)[SkMatrix::kMTransX];
-            SkScalar ty = matrix[SkMatrix::kMTransY] + (coordChangeMatrix)[SkMatrix::kMTransY];
-            if (fPrevMatrix.get(SkMatrix::kMTransX) != tx ||
-                fPrevMatrix.get(SkMatrix::kMTransY) != ty) {
-                uniformManager.set2f(fUni, tx, ty);
-                fPrevMatrix.set(SkMatrix::kMTransX, tx);
-                fPrevMatrix.set(SkMatrix::kMTransY, ty);
-            }
-            break;
-        }
-        case kMat33f_GrSLType: {
-            SkMatrix combined;
-            combined.setConcat(matrix, coordChangeMatrix);
-            if (NULL != texture && kBottomLeft_GrSurfaceOrigin == texture->origin()) {
-                // combined.postScale(1,-1);
-                // combined.postTranslate(0,1);
-                combined.set(SkMatrix::kMSkewY,
-                    combined[SkMatrix::kMPersp0] - combined[SkMatrix::kMSkewY]);
-                combined.set(SkMatrix::kMScaleY,
-                    combined[SkMatrix::kMPersp1] - combined[SkMatrix::kMScaleY]);
-                combined.set(SkMatrix::kMTransY,
-                    combined[SkMatrix::kMPersp2] - combined[SkMatrix::kMTransY]);
-            }
-            if (!fPrevMatrix.cheapEqualTo(combined)) {
-                uniformManager.setSkMatrix(fUni, combined);
-                fPrevMatrix = combined;
-            }
-            break;
-        }
-        default:
-            GrCrash("Unexpected uniform type.");
-    }
-}