1/*
2 * Copyright 2013 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 GrGLVertexArray_DEFINED
9#define GrGLVertexArray_DEFINED
10
11#include "GrResource.h"
12#include "GrTypesPriv.h"
13#include "gl/GrGLDefines.h"
14#include "gl/GrGLFunctions.h"
15
16#include "SkTArray.h"
17
18class GrGLVertexBuffer;
19class GrGLIndexBuffer;
20class GrGpuGL;
21
22struct GrGLAttribLayout {
23    GrGLint     fCount;
24    GrGLenum    fType;
25    GrGLboolean fNormalized;
26};
27
28static inline const GrGLAttribLayout& GrGLAttribTypeToLayout(GrVertexAttribType type) {
29    SkASSERT(type >= 0 && type < kGrVertexAttribTypeCount);
30    static const GrGLAttribLayout kLayouts[kGrVertexAttribTypeCount] = {
31        {1, GR_GL_FLOAT, false},         // kFloat_GrVertexAttribType
32        {2, GR_GL_FLOAT, false},         // kVec2f_GrVertexAttribType
33        {3, GR_GL_FLOAT, false},         // kVec3f_GrVertexAttribType
34        {4, GR_GL_FLOAT, false},         // kVec4f_GrVertexAttribType
35        {4, GR_GL_UNSIGNED_BYTE, true},  // kVec4ub_GrVertexAttribType
36    };
37    GR_STATIC_ASSERT(0 == kFloat_GrVertexAttribType);
38    GR_STATIC_ASSERT(1 == kVec2f_GrVertexAttribType);
39    GR_STATIC_ASSERT(2 == kVec3f_GrVertexAttribType);
40    GR_STATIC_ASSERT(3 == kVec4f_GrVertexAttribType);
41    GR_STATIC_ASSERT(4 == kVec4ub_GrVertexAttribType);
42    GR_STATIC_ASSERT(SK_ARRAY_COUNT(kLayouts) == kGrVertexAttribTypeCount);
43    return kLayouts[type];
44}
45
46/**
47 * This sets and tracks the vertex attribute array state. It is used internally by GrGLVertexArray
48 * (below) but is separate because it is also used to track the state of vertex array object 0.
49 */
50class GrGLAttribArrayState {
51public:
52    explicit GrGLAttribArrayState(int arrayCount = 0) {
53        this->resize(arrayCount);
54        // glVertexPointer doesn't have a normalization param.
55        fFixedFunctionVertexArray.fNormalized = false;
56        fUnusedFixedFunctionArraysDisabled = false;
57    }
58
59    void resize(int newCount) {
60        fAttribArrayStates.resize_back(newCount);
61        for (int i = 0; i < newCount; ++i) {
62            fAttribArrayStates[i].invalidate();
63        }
64    }
65
66    /**
67     * This function enables and sets vertex attrib state for the specified attrib index. It is
68     * assumed that the GrGLAttribArrayState is tracking the state of the currently bound vertex
69     * array object.
70     */
71    void set(const GrGpuGL*,
72             int index,
73             GrGLVertexBuffer*,
74             GrGLint size,
75             GrGLenum type,
76             GrGLboolean normalized,
77             GrGLsizei stride,
78             GrGLvoid* offset);
79
80    void setFixedFunctionVertexArray(const GrGpuGL*,
81                                     GrGLVertexBuffer*,
82                                     GrGLint size,
83                                     GrGLenum type,
84                                     GrGLsizei stride,
85                                     GrGLvoid* offset);
86
87    /**
88     * This function disables vertex attribs not present in the mask. It is assumed that the
89     * GrGLAttribArrayState is tracking the state of the currently bound vertex array object.
90     */
91    void disableUnusedArrays(const GrGpuGL*, uint64_t usedAttribArrayMask, bool usingFFVertexArray);
92
93    void invalidate() {
94        int count = fAttribArrayStates.count();
95        for (int i = 0; i < count; ++i) {
96            fAttribArrayStates[i].invalidate();
97        }
98        fFixedFunctionVertexArray.invalidate();
99        fUnusedFixedFunctionArraysDisabled = false;
100    }
101
102    void notifyVertexBufferDelete(GrGLuint id) {
103        int count = fAttribArrayStates.count();
104        for (int i = 0; i < count; ++i) {
105            if (fAttribArrayStates[i].fAttribPointerIsValid &&
106                id == fAttribArrayStates[i].fVertexBufferID) {
107                fAttribArrayStates[i].invalidate();
108            }
109        }
110        if (fFixedFunctionVertexArray.fAttribPointerIsValid &&
111            id == fFixedFunctionVertexArray.fVertexBufferID) {
112            fFixedFunctionVertexArray.invalidate();
113        }
114    }
115
116    /**
117     * The number of attrib arrays that this object is configured to track.
118     */
119    int count() const { return fAttribArrayStates.count(); }
120
121private:
122    /**
123     * Tracks the state of glVertexAttribArray for an attribute index.
124     */
125    struct AttribArrayState {
126            void invalidate() {
127                fEnableIsValid = false;
128                fAttribPointerIsValid = false;
129            }
130
131            bool        fEnableIsValid;
132            bool        fAttribPointerIsValid;
133            bool        fEnabled;
134            GrGLuint    fVertexBufferID;
135            GrGLint     fSize;
136            GrGLenum    fType;
137            GrGLboolean fNormalized;
138            GrGLsizei   fStride;
139            GrGLvoid*   fOffset;
140    };
141
142    SkSTArray<16, AttribArrayState, true> fAttribArrayStates;
143
144    // Tracks the array specified by glVertexPointer.
145    AttribArrayState fFixedFunctionVertexArray;
146
147    // Tracks whether we've disabled the other fixed function arrays that we don't
148    // use (e.g. glNormalPointer).
149    bool fUnusedFixedFunctionArraysDisabled;
150};
151
152/**
153 * This class represents an OpenGL vertex array object. It manages the lifetime of the vertex array
154 * and is used to track the state of the vertex array to avoid redundant GL calls.
155 */
156class GrGLVertexArray : public GrResource {
157public:
158    GrGLVertexArray(GrGpuGL* gpu, GrGLint id, int attribCount);
159
160    /**
161     * Binds this vertex array. If the ID has been deleted or abandoned then NULL is returned.
162     * Otherwise, the GrGLAttribArrayState that is tracking this vertex array's attrib bindings is
163     * returned.
164     */
165    GrGLAttribArrayState* bind();
166
167    /**
168     * This is a version of the above function that also binds an index buffer to the vertex
169     * array object.
170     */
171    GrGLAttribArrayState* bindWithIndexBuffer(const GrGLIndexBuffer* indexBuffer);
172
173    void notifyIndexBufferDelete(GrGLuint bufferID);
174
175    void notifyVertexBufferDelete(GrGLuint id) {
176        fAttribArrays.notifyVertexBufferDelete(id);
177    }
178
179    GrGLuint arrayID() const { return fID; }
180
181    void invalidateCachedState();
182
183    virtual size_t sizeInBytes() const SK_OVERRIDE { return 0; }
184
185protected:
186    virtual void onAbandon() SK_OVERRIDE;
187
188    virtual void onRelease() SK_OVERRIDE;
189
190private:
191    GrGLuint                fID;
192    GrGLAttribArrayState    fAttribArrays;
193    GrGLuint                fIndexBufferID;
194    bool                    fIndexBufferIDIsValid;
195
196    typedef GrResource INHERITED;
197};
198
199#endif
200