michael@0: /*
michael@0:  * Copyright 2012 Google Inc.
michael@0:  *
michael@0:  * Use of this source code is governed by a BSD-style license that can be
michael@0:  * found in the LICENSE file.
michael@0:  */
michael@0: 
michael@0: 
michael@0: #ifndef GrGLCaps_DEFINED
michael@0: #define GrGLCaps_DEFINED
michael@0: 
michael@0: #include "GrDrawTargetCaps.h"
michael@0: #include "GrGLStencilBuffer.h"
michael@0: #include "SkTArray.h"
michael@0: #include "SkTDArray.h"
michael@0: 
michael@0: class GrGLContextInfo;
michael@0: 
michael@0: /**
michael@0:  * Stores some capabilities of a GL context. Most are determined by the GL
michael@0:  * version and the extensions string. It also tracks formats that have passed
michael@0:  * the FBO completeness test.
michael@0:  */
michael@0: class GrGLCaps : public GrDrawTargetCaps {
michael@0: public:
michael@0:     SK_DECLARE_INST_COUNT(GrGLCaps)
michael@0: 
michael@0:     typedef GrGLStencilBuffer::Format StencilFormat;
michael@0: 
michael@0:     /**
michael@0:      * The type of MSAA for FBOs supported. Different extensions have different
michael@0:      * semantics of how / when a resolve is performed.
michael@0:      */
michael@0:     enum MSFBOType {
michael@0:         /**
michael@0:          * no support for MSAA FBOs
michael@0:          */
michael@0:         kNone_MSFBOType = 0,
michael@0:         /**
michael@0:          * GL3.0-style MSAA FBO (GL_ARB_framebuffer_object).
michael@0:          */
michael@0:         kDesktop_ARB_MSFBOType,
michael@0:         /**
michael@0:          * earlier GL_EXT_framebuffer* extensions
michael@0:          */
michael@0:         kDesktop_EXT_MSFBOType,
michael@0:         /**
michael@0:          * Similar to kDesktop_ARB but with additional restrictions on glBlitFramebuffer.
michael@0:          */
michael@0:         kES_3_0_MSFBOType,
michael@0:         /**
michael@0:          * GL_APPLE_framebuffer_multisample ES extension
michael@0:          */
michael@0:         kES_Apple_MSFBOType,
michael@0:         /**
michael@0:          * GL_IMG_multisampled_render_to_texture. This variation does not have MSAA renderbuffers.
michael@0:          * Instead the texture is multisampled when bound to the FBO and then resolved automatically
michael@0:          * when read. It also defines an alternate value for GL_MAX_SAMPLES (which we call
michael@0:          * GR_GL_MAX_SAMPLES_IMG).
michael@0:          */
michael@0:         kES_IMG_MsToTexture_MSFBOType,
michael@0:         /**
michael@0:          * GL_EXT_multisampled_render_to_texture. Same as the IMG one above but uses the standard
michael@0:          * GL_MAX_SAMPLES value.
michael@0:          */
michael@0:         kES_EXT_MsToTexture_MSFBOType,
michael@0: 
michael@0:         kLast_MSFBOType = kES_EXT_MsToTexture_MSFBOType
michael@0:     };
michael@0: 
michael@0:     enum FBFetchType {
michael@0:         kNone_FBFetchType,
michael@0:         /** GL_EXT_shader_framebuffer_fetch */
michael@0:         kEXT_FBFetchType,
michael@0:         /** GL_NV_shader_framebuffer_fetch */
michael@0:         kNV_FBFetchType,
michael@0: 
michael@0:         kLast_FBFetchType = kNV_FBFetchType,
michael@0:     };
michael@0: 
michael@0:     /**
michael@0:      * Creates a GrGLCaps that advertises no support for any extensions,
michael@0:      * formats, etc. Call init to initialize from a GrGLContextInfo.
michael@0:      */
michael@0:     GrGLCaps();
michael@0: 
michael@0:     GrGLCaps(const GrGLCaps& caps);
michael@0: 
michael@0:     GrGLCaps& operator = (const GrGLCaps& caps);
michael@0: 
michael@0:     /**
michael@0:      * Resets the caps such that nothing is supported.
michael@0:      */
michael@0:     virtual void reset() SK_OVERRIDE;
michael@0: 
michael@0:     /**
michael@0:      * Initializes the GrGLCaps to the set of features supported in the current
michael@0:      * OpenGL context accessible via ctxInfo.
michael@0:      */
michael@0:     void init(const GrGLContextInfo& ctxInfo, const GrGLInterface* interface);
michael@0: 
michael@0:     /**
michael@0:      * Call to note that a color config has been verified as a valid color
michael@0:      * attachment. This may save future calls to glCheckFramebufferStatus
michael@0:      * using isConfigVerifiedColorAttachment().
michael@0:      */
michael@0:     void markConfigAsValidColorAttachment(GrPixelConfig config) {
michael@0:         fVerifiedColorConfigs.markVerified(config);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Call to check whether a config has been verified as a valid color
michael@0:      * attachment.
michael@0:      */
michael@0:     bool isConfigVerifiedColorAttachment(GrPixelConfig config) const {
michael@0:         return fVerifiedColorConfigs.isVerified(config);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Call to note that a color config / stencil format pair passed
michael@0:      * FBO status check. We may skip calling glCheckFramebufferStatus for
michael@0:      * this combination in the future using
michael@0:      * isColorConfigAndStencilFormatVerified().
michael@0:      */
michael@0:     void markColorConfigAndStencilFormatAsVerified(
michael@0:                     GrPixelConfig config,
michael@0:                     const GrGLStencilBuffer::Format& format);
michael@0: 
michael@0:     /**
michael@0:      * Call to check whether color config / stencil format pair has already
michael@0:      * passed FBO status check.
michael@0:      */
michael@0:     bool isColorConfigAndStencilFormatVerified(
michael@0:                     GrPixelConfig config,
michael@0:                     const GrGLStencilBuffer::Format& format) const;
michael@0: 
michael@0:     /**
michael@0:      * Reports the type of MSAA FBO support.
michael@0:      */
michael@0:     MSFBOType msFBOType() const { return fMSFBOType; }
michael@0: 
michael@0:     /**
michael@0:      * Does the supported MSAA FBO extension have MSAA renderbuffers?
michael@0:      */
michael@0:     bool usesMSAARenderBuffers() const {
michael@0:         return kNone_MSFBOType != fMSFBOType &&
michael@0:                kES_IMG_MsToTexture_MSFBOType != fMSFBOType &&
michael@0:                kES_EXT_MsToTexture_MSFBOType != fMSFBOType;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Is the MSAA FBO extension one where the texture is multisampled when bound to an FBO and
michael@0:      * then implicitly resolved when read.
michael@0:      */
michael@0:     bool usesImplicitMSAAResolve() const {
michael@0:         return kES_IMG_MsToTexture_MSFBOType == fMSFBOType ||
michael@0:                kES_EXT_MsToTexture_MSFBOType == fMSFBOType;
michael@0:     }
michael@0: 
michael@0:     FBFetchType fbFetchType() const { return fFBFetchType; }
michael@0: 
michael@0:     /**
michael@0:      * Returs a string containeng the caps info.
michael@0:      */
michael@0:     virtual SkString dump() const SK_OVERRIDE;
michael@0: 
michael@0:     /**
michael@0:      * Gets an array of legal stencil formats. These formats are not guaranteed
michael@0:      * to be supported by the driver but are legal GLenum names given the GL
michael@0:      * version and extensions supported.
michael@0:      */
michael@0:     const SkTArray<StencilFormat, true>& stencilFormats() const {
michael@0:         return fStencilFormats;
michael@0:     }
michael@0: 
michael@0:     /// The maximum number of fragment uniform vectors (GLES has min. 16).
michael@0:     int maxFragmentUniformVectors() const { return fMaxFragmentUniformVectors; }
michael@0: 
michael@0:     /// maximum number of attribute values per vertex
michael@0:     int maxVertexAttributes() const { return fMaxVertexAttributes; }
michael@0: 
michael@0:     /// maximum number of texture units accessible in the fragment shader.
michael@0:     int maxFragmentTextureUnits() const { return fMaxFragmentTextureUnits; }
michael@0: 
michael@0:     /// maximum number of fixed-function texture coords, or zero if no fixed-function.
michael@0:     int maxFixedFunctionTextureCoords() const { return fMaxFixedFunctionTextureCoords; }
michael@0: 
michael@0:     /// ES requires an extension to support RGBA8 in RenderBufferStorage
michael@0:     bool rgba8RenderbufferSupport() const { return fRGBA8RenderbufferSupport; }
michael@0: 
michael@0:     /// Is GL_BGRA supported
michael@0:     bool bgraFormatSupport() const { return fBGRAFormatSupport; }
michael@0: 
michael@0:     /**
michael@0:      * Depending on the ES extensions present the BGRA external format may
michael@0:      * correspond either a BGRA or RGBA internalFormat. On desktop GL it is
michael@0:      * RGBA.
michael@0:      */
michael@0:     bool bgraIsInternalFormat() const { return fBGRAIsInternalFormat; }
michael@0: 
michael@0:     /// GL_ARB_texture_swizzle support
michael@0:     bool textureSwizzleSupport() const { return fTextureSwizzleSupport; }
michael@0: 
michael@0:     /// Is there support for GL_UNPACK_ROW_LENGTH
michael@0:     bool unpackRowLengthSupport() const { return fUnpackRowLengthSupport; }
michael@0: 
michael@0:     /// Is there support for GL_UNPACK_FLIP_Y
michael@0:     bool unpackFlipYSupport() const { return fUnpackFlipYSupport; }
michael@0: 
michael@0:     /// Is there support for GL_PACK_ROW_LENGTH
michael@0:     bool packRowLengthSupport() const { return fPackRowLengthSupport; }
michael@0: 
michael@0:     /// Is there support for GL_PACK_REVERSE_ROW_ORDER
michael@0:     bool packFlipYSupport() const { return fPackFlipYSupport; }
michael@0: 
michael@0:     /// Is there support for texture parameter GL_TEXTURE_USAGE
michael@0:     bool textureUsageSupport() const { return fTextureUsageSupport; }
michael@0: 
michael@0:     /// Is there support for glTexStorage
michael@0:     bool texStorageSupport() const { return fTexStorageSupport; }
michael@0: 
michael@0:     /// Is there support for GL_RED and GL_R8
michael@0:     bool textureRedSupport() const { return fTextureRedSupport; }
michael@0: 
michael@0:     /// Is GL_ARB_IMAGING supported
michael@0:     bool imagingSupport() const { return fImagingSupport; }
michael@0: 
michael@0:     /// Is GL_ARB_fragment_coord_conventions supported?
michael@0:     bool fragCoordConventionsSupport() const { return fFragCoordsConventionSupport; }
michael@0: 
michael@0:     /// Is there support for Vertex Array Objects?
michael@0:     bool vertexArrayObjectSupport() const { return fVertexArrayObjectSupport; }
michael@0: 
michael@0:     /// Use indices or vertices in CPU arrays rather than VBOs for dynamic content.
michael@0:     bool useNonVBOVertexAndIndexDynamicData() const {
michael@0:         return fUseNonVBOVertexAndIndexDynamicData;
michael@0:     }
michael@0: 
michael@0:     /// Does ReadPixels support the provided format/type combo?
michael@0:     bool readPixelsSupported(const GrGLInterface* intf,
michael@0:                              GrGLenum format,
michael@0:                              GrGLenum type) const;
michael@0: 
michael@0:     bool isCoreProfile() const { return fIsCoreProfile; }
michael@0: 
michael@0:     bool fixedFunctionSupport() const { return fFixedFunctionSupport; }
michael@0: 
michael@0:     /// Is there support for discarding the frame buffer
michael@0:     bool discardFBSupport() const { return fDiscardFBSupport; }
michael@0: 
michael@0:     bool fullClearIsFree() const { return fFullClearIsFree; }
michael@0: 
michael@0: private:
michael@0:     /**
michael@0:      * Maintains a bit per GrPixelConfig. It is used to avoid redundantly
michael@0:      * performing glCheckFrameBufferStatus for the same config.
michael@0:      */
michael@0:     struct VerifiedColorConfigs {
michael@0:         VerifiedColorConfigs() {
michael@0:             this->reset();
michael@0:         }
michael@0: 
michael@0:         void reset() {
michael@0:             for (int i = 0; i < kNumUints; ++i) {
michael@0:                 fVerifiedColorConfigs[i] = 0;
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         static const int kNumUints = (kGrPixelConfigCnt  + 31) / 32;
michael@0:         uint32_t fVerifiedColorConfigs[kNumUints];
michael@0: 
michael@0:         void markVerified(GrPixelConfig config) {
michael@0: #if !GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT
michael@0:                 return;
michael@0: #endif
michael@0:             int u32Idx = config / 32;
michael@0:             int bitIdx = config % 32;
michael@0:             fVerifiedColorConfigs[u32Idx] |= 1 << bitIdx;
michael@0:         }
michael@0: 
michael@0:         bool isVerified(GrPixelConfig config) const {
michael@0: #if !GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT
michael@0:             return false;
michael@0: #endif
michael@0:             int u32Idx = config / 32;
michael@0:             int bitIdx = config % 32;
michael@0:             return SkToBool(fVerifiedColorConfigs[u32Idx] & (1 << bitIdx));
michael@0:         }
michael@0:     };
michael@0: 
michael@0:     void initFSAASupport(const GrGLContextInfo&, const GrGLInterface*);
michael@0:     void initStencilFormats(const GrGLContextInfo&);
michael@0:     // This must be called after initFSAASupport().
michael@0:     void initConfigRenderableTable(const GrGLContextInfo&);
michael@0: 
michael@0:     // tracks configs that have been verified to pass the FBO completeness when
michael@0:     // used as a color attachment
michael@0:     VerifiedColorConfigs fVerifiedColorConfigs;
michael@0: 
michael@0:     SkTArray<StencilFormat, true> fStencilFormats;
michael@0:     // tracks configs that have been verified to pass the FBO completeness when
michael@0:     // used as a color attachment when a particular stencil format is used
michael@0:     // as a stencil attachment.
michael@0:     SkTArray<VerifiedColorConfigs, true> fStencilVerifiedColorConfigs;
michael@0: 
michael@0:     int fMaxFragmentUniformVectors;
michael@0:     int fMaxVertexAttributes;
michael@0:     int fMaxFragmentTextureUnits;
michael@0:     int fMaxFixedFunctionTextureCoords;
michael@0: 
michael@0:     MSFBOType fMSFBOType;
michael@0: 
michael@0:     FBFetchType fFBFetchType;
michael@0: 
michael@0:     bool fRGBA8RenderbufferSupport : 1;
michael@0:     bool fBGRAFormatSupport : 1;
michael@0:     bool fBGRAIsInternalFormat : 1;
michael@0:     bool fTextureSwizzleSupport : 1;
michael@0:     bool fUnpackRowLengthSupport : 1;
michael@0:     bool fUnpackFlipYSupport : 1;
michael@0:     bool fPackRowLengthSupport : 1;
michael@0:     bool fPackFlipYSupport : 1;
michael@0:     bool fTextureUsageSupport : 1;
michael@0:     bool fTexStorageSupport : 1;
michael@0:     bool fTextureRedSupport : 1;
michael@0:     bool fImagingSupport  : 1;
michael@0:     bool fTwoFormatLimit : 1;
michael@0:     bool fFragCoordsConventionSupport : 1;
michael@0:     bool fVertexArrayObjectSupport : 1;
michael@0:     bool fUseNonVBOVertexAndIndexDynamicData : 1;
michael@0:     bool fIsCoreProfile : 1;
michael@0:     bool fFixedFunctionSupport : 1;
michael@0:     bool fDiscardFBSupport : 1;
michael@0:     bool fFullClearIsFree : 1;
michael@0: 
michael@0:     typedef GrDrawTargetCaps INHERITED;
michael@0: };
michael@0: 
michael@0: #endif