include/gpu/gl/GrGLConfig.h - platform/external/skqp - Gitiles


 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */


 #ifndef GrGLConfig_DEFINED
 #define GrGLConfig_DEFINED

 #include "GrTypes.h"

 /**
  * Optional GL config file.
  */
 #ifdef GR_GL_CUSTOM_SETUP_HEADER
     #include GR_GL_CUSTOM_SETUP_HEADER
 #endif

 #if !defined(GR_GL_FUNCTION_TYPE)
     #define GR_GL_FUNCTION_TYPE
 #endif

 /**
  * The following are optional defines that can be enabled at the compiler
  * command line, in a IDE project, in a GrUserConfig.h file, or in a GL custom
  * file (if one is in use). If a GR_GL_CUSTOM_SETUP_HEADER is used they can
  * also be placed there.
  *
  * GR_GL_LOG_CALLS: if 1 Gr can print every GL call using GrPrintf. Defaults to
  * 0. Logging can be enabled and disabled at runtime using a debugger via to
  * global gLogCallsGL. The initial value of gLogCallsGL is controlled by
  * GR_GL_LOG_CALLS_START.
  *
  * GR_GL_LOG_CALLS_START: controls the initial value of gLogCallsGL when
  * GR_GL_LOG_CALLS is 1. Defaults to 0.
  *
  * GR_GL_CHECK_ERROR: if enabled Gr can do a glGetError() after every GL call.
  * Defaults to 1 if GR_DEBUG is set, otherwise 0. When GR_GL_CHECK_ERROR is 1
  * this can be toggled in a debugger using the gCheckErrorGL global. The initial
  * value of gCheckErrorGL is controlled by by GR_GL_CHECK_ERROR_START.
  *
  * GR_GL_CHECK_ERROR_START: controls the initial value of gCheckErrorGL
  * when GR_GL_CHECK_ERROR is 1.  Defaults to 1.
  *
  * GR_GL_NO_CONSTANT_ATTRIBUTES: if this evaluates to true then the GL backend
  * will use uniforms instead of attributes in all cases when there is not
  * per-vertex data. This is important when the underlying GL implementation
  * doesn't actually support immediate style attribute values (e.g. when
  * the GL stream is converted to DX as in ANGLE on Chrome). Defaults to 0.
  *
  * GR_GL_USE_BUFFER_DATA_NULL_HINT: When specifing new data for a vertex/index
  * buffer that replaces old data Ganesh can give a hint to the driver that the
  * previous data will not be used in future draws like this:
  *  glBufferData(GL_..._BUFFER, size, NULL, usage);       //<--hint, NULL means
  *  glBufferSubData(GL_..._BUFFER, 0, lessThanSize, data) //   old data can't be
  *                                                        //   used again.
  * However, this can be an unoptimization on some platforms, esp. Chrome.
  * Chrome's cmd buffer will create a new allocation and memset the whole thing
  * to zero (for security reasons). Defaults to 1 (enabled).
  *
  * GR_GL_PER_GL_FUNC_CALLBACK: When set to 1 the GrGLInterface object provides
  * a function pointer that is called just before every gl function. The ptr must
  * be valid (i.e. there is no NULL check). However, by default the callback will
  * be set to a function that does nothing. The signature of the function is:
  *    void function(const GrGLInterface*)
  * It is not extern "C".
  * The GrGLInterface field fCallback specifies the function ptr and there is an
  * additional field fCallbackData of type intptr_t for client data.
  *
  * GR_GL_RGBA_8888_PIXEL_OPS_SLOW: Set this to 1 if it is known that performing
  * glReadPixels / glTex(Sub)Image with format=GL_RGBA, type=GL_UNISIGNED_BYTE is
  * significantly slower than format=GL_BGRA, type=GL_UNISIGNED_BYTE.
  *
  * GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL: Set this to 1 if calling
  * glReadPixels to read the entire framebuffer is faster than calling it with
  * the same sized rectangle but with a framebuffer bound that is larger than
  * the rectangle read.
  *
  * GR_GL_CHECK_ALLOC_WITH_GET_ERROR: If set to 1 this will then glTexImage,
  * glBufferData, glRenderbufferStorage, etc will be checked for errors. This
  * amounts to ensuring the error is GL_NO_ERROR, calling the allocating
  * function, and then checking that the error is still GL_NO_ERROR. When the
  * value is 0 we will assume no error was generated without checking.
  *
  * GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT: We will normally check the FBO status
  * every time we bind a texture or renderbuffer to an FBO. However, in some
  * environments CheckFrameBufferStatus is very expensive. If this is set we will
  * check the first time we use a color format or a combination of color /
  * stencil formats as attachments. If the FBO is complete we will assume
  * subsequent attachments with the same formats are complete as well.
  *
  * GR_GL_USE_NV_PATH_RENDERING: Enable experimental support for
  * GL_NV_path_rendering. There are known issues with clipping, non-AA paths, and
  * perspective.
  */

 #if !defined(GR_GL_LOG_CALLS)
     #define GR_GL_LOG_CALLS                             GR_DEBUG
 #endif

 #if !defined(GR_GL_LOG_CALLS_START)
     #define GR_GL_LOG_CALLS_START                       0
 #endif

 #if !defined(GR_GL_CHECK_ERROR)
     #define GR_GL_CHECK_ERROR                           GR_DEBUG
 #endif

 #if !defined(GR_GL_CHECK_ERROR_START)
     #define GR_GL_CHECK_ERROR_START                     1
 #endif

 #if !defined(GR_GL_NO_CONSTANT_ATTRIBUTES)
     #define GR_GL_NO_CONSTANT_ATTRIBUTES                0
 #endif

 #if !defined(GR_GL_USE_BUFFER_DATA_NULL_HINT)
     #define GR_GL_USE_BUFFER_DATA_NULL_HINT             1
 #endif

 #if !defined(GR_GL_PER_GL_FUNC_CALLBACK)
     #define GR_GL_PER_GL_FUNC_CALLBACK                  0
 #endif

 #if !defined(GR_GL_RGBA_8888_PIXEL_OPS_SLOW)
     #define GR_GL_RGBA_8888_PIXEL_OPS_SLOW              0
 #endif

 #if !defined(GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL)
     #define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL   0
 #endif

 #if !defined(GR_GL_CHECK_ALLOC_WITH_GET_ERROR)
     #define GR_GL_CHECK_ALLOC_WITH_GET_ERROR            1
 #endif

 #if !defined(GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT)
     #define GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT      0
 #endif

 #if !defined(GR_GL_USE_NV_PATH_RENDERING)
     #define GR_GL_USE_NV_PATH_RENDERING                 0
 #endif

 /**
  * There is a strange bug that occurs on Macs with NVIDIA GPUs. We don't
  * fully understand it. When (element) array buffers are continually
  * respecified using glBufferData performance can fall off of a cliff. The
  * driver winds up performing many DMA mapping / unmappings and chews up ~50% of
  * the core. However, it has been observed that occaisonally respecifiying the
  * buffer using glBufferData and then writing data using glBufferSubData
  * prevents the bad behavior.
  *
  * There is a lot of uncertainty around this issue. In Chrome backgrounding
  * the tab somehow initiates this behavior and we don't know what the connection
  * is. Another observation is that Chrome's cmd buffer server will actually
  * create a buffer full of zeros when it sees a NULL data param (for security
  * reasons). If this is disabled and NULL is actually passed all the way to the
  * driver then the workaround doesn't help.
  *
  * The issue is tracked at:
  * http://code.google.com/p/chromium/issues/detail?id=114865
  *
  * When the workaround is enabled we will use the glBufferData / glBufferSubData
  * trick every 128 array buffer uploads.
  *
  * Hopefully we will understand this better and have a cleaner fix or get a
  * OS/driver level fix.
  */
 #define GR_GL_MAC_BUFFER_OBJECT_PERFOMANCE_WORKAROUND   \
     (GR_MAC_BUILD &&                                    \
      !GR_GL_USE_BUFFER_DATA_NULL_HINT)

 #endif

	/*
	* Copyright 2011 Google Inc.
	*
	* Use of this source code is governed by a BSD-style license that can be
	* found in the LICENSE file.
	*/



	#ifndef GrGLConfig_DEFINED
	#define GrGLConfig_DEFINED

	#include "GrTypes.h"

	/**
	* Optional GL config file.
	*/
	#ifdef GR_GL_CUSTOM_SETUP_HEADER
	#include GR_GL_CUSTOM_SETUP_HEADER
	#endif

	#if !defined(GR_GL_FUNCTION_TYPE)
	#define GR_GL_FUNCTION_TYPE
	#endif

	/**
	* The following are optional defines that can be enabled at the compiler
	* command line, in a IDE project, in a GrUserConfig.h file, or in a GL custom
	* file (if one is in use). If a GR_GL_CUSTOM_SETUP_HEADER is used they can
	* also be placed there.
	*
	* GR_GL_LOG_CALLS: if 1 Gr can print every GL call using GrPrintf. Defaults to
	* 0. Logging can be enabled and disabled at runtime using a debugger via to
	* global gLogCallsGL. The initial value of gLogCallsGL is controlled by
	* GR_GL_LOG_CALLS_START.
	*
	* GR_GL_LOG_CALLS_START: controls the initial value of gLogCallsGL when
	* GR_GL_LOG_CALLS is 1. Defaults to 0.
	*
	* GR_GL_CHECK_ERROR: if enabled Gr can do a glGetError() after every GL call.
	* Defaults to 1 if GR_DEBUG is set, otherwise 0. When GR_GL_CHECK_ERROR is 1
	* this can be toggled in a debugger using the gCheckErrorGL global. The initial
	* value of gCheckErrorGL is controlled by by GR_GL_CHECK_ERROR_START.
	*
	* GR_GL_CHECK_ERROR_START: controls the initial value of gCheckErrorGL
	* when GR_GL_CHECK_ERROR is 1. Defaults to 1.
	*
	* GR_GL_NO_CONSTANT_ATTRIBUTES: if this evaluates to true then the GL backend
	* will use uniforms instead of attributes in all cases when there is not
	* per-vertex data. This is important when the underlying GL implementation
	* doesn't actually support immediate style attribute values (e.g. when
	* the GL stream is converted to DX as in ANGLE on Chrome). Defaults to 0.
	*
	* GR_GL_USE_BUFFER_DATA_NULL_HINT: When specifing new data for a vertex/index
	* buffer that replaces old data Ganesh can give a hint to the driver that the
	* previous data will not be used in future draws like this:
	* glBufferData(GL_..._BUFFER, size, NULL, usage); //<--hint, NULL means
	* glBufferSubData(GL_..._BUFFER, 0, lessThanSize, data) // old data can't be
	* // used again.
	* However, this can be an unoptimization on some platforms, esp. Chrome.
	* Chrome's cmd buffer will create a new allocation and memset the whole thing
	* to zero (for security reasons). Defaults to 1 (enabled).
	*
	* GR_GL_PER_GL_FUNC_CALLBACK: When set to 1 the GrGLInterface object provides
	* a function pointer that is called just before every gl function. The ptr must
	* be valid (i.e. there is no NULL check). However, by default the callback will
	* be set to a function that does nothing. The signature of the function is:
	* void function(const GrGLInterface*)
	* It is not extern "C".
	* The GrGLInterface field fCallback specifies the function ptr and there is an
	* additional field fCallbackData of type intptr_t for client data.
	*
	* GR_GL_RGBA_8888_PIXEL_OPS_SLOW: Set this to 1 if it is known that performing
	* glReadPixels / glTex(Sub)Image with format=GL_RGBA, type=GL_UNISIGNED_BYTE is
	* significantly slower than format=GL_BGRA, type=GL_UNISIGNED_BYTE.
	*
	* GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL: Set this to 1 if calling
	* glReadPixels to read the entire framebuffer is faster than calling it with
	* the same sized rectangle but with a framebuffer bound that is larger than
	* the rectangle read.
	*
	* GR_GL_CHECK_ALLOC_WITH_GET_ERROR: If set to 1 this will then glTexImage,
	* glBufferData, glRenderbufferStorage, etc will be checked for errors. This
	* amounts to ensuring the error is GL_NO_ERROR, calling the allocating
	* function, and then checking that the error is still GL_NO_ERROR. When the
	* value is 0 we will assume no error was generated without checking.
	*
	* GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT: We will normally check the FBO status
	* every time we bind a texture or renderbuffer to an FBO. However, in some
	* environments CheckFrameBufferStatus is very expensive. If this is set we will
	* check the first time we use a color format or a combination of color /
	* stencil formats as attachments. If the FBO is complete we will assume
	* subsequent attachments with the same formats are complete as well.
	*
	* GR_GL_USE_NV_PATH_RENDERING: Enable experimental support for
	* GL_NV_path_rendering. There are known issues with clipping, non-AA paths, and
	* perspective.
	*/

	#if !defined(GR_GL_LOG_CALLS)
	#define GR_GL_LOG_CALLS GR_DEBUG
	#endif

	#if !defined(GR_GL_LOG_CALLS_START)
	#define GR_GL_LOG_CALLS_START 0
	#endif

	#if !defined(GR_GL_CHECK_ERROR)
	#define GR_GL_CHECK_ERROR GR_DEBUG
	#endif

	#if !defined(GR_GL_CHECK_ERROR_START)
	#define GR_GL_CHECK_ERROR_START 1
	#endif

	#if !defined(GR_GL_NO_CONSTANT_ATTRIBUTES)
	#define GR_GL_NO_CONSTANT_ATTRIBUTES 0
	#endif

	#if !defined(GR_GL_USE_BUFFER_DATA_NULL_HINT)
	#define GR_GL_USE_BUFFER_DATA_NULL_HINT 1
	#endif

	#if !defined(GR_GL_PER_GL_FUNC_CALLBACK)
	#define GR_GL_PER_GL_FUNC_CALLBACK 0
	#endif

	#if !defined(GR_GL_RGBA_8888_PIXEL_OPS_SLOW)
	#define GR_GL_RGBA_8888_PIXEL_OPS_SLOW 0
	#endif

	#if !defined(GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL)
	#define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL 0
	#endif

	#if !defined(GR_GL_CHECK_ALLOC_WITH_GET_ERROR)
	#define GR_GL_CHECK_ALLOC_WITH_GET_ERROR 1
	#endif

	#if !defined(GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT)
	#define GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT 0
	#endif

	#if !defined(GR_GL_USE_NV_PATH_RENDERING)
	#define GR_GL_USE_NV_PATH_RENDERING 0
	#endif

	/**
	* There is a strange bug that occurs on Macs with NVIDIA GPUs. We don't
	* fully understand it. When (element) array buffers are continually
	* respecified using glBufferData performance can fall off of a cliff. The
	* driver winds up performing many DMA mapping / unmappings and chews up ~50% of
	* the core. However, it has been observed that occaisonally respecifiying the
	* buffer using glBufferData and then writing data using glBufferSubData
	* prevents the bad behavior.
	*
	* There is a lot of uncertainty around this issue. In Chrome backgrounding
	* the tab somehow initiates this behavior and we don't know what the connection
	* is. Another observation is that Chrome's cmd buffer server will actually
	* create a buffer full of zeros when it sees a NULL data param (for security
	* reasons). If this is disabled and NULL is actually passed all the way to the
	* driver then the workaround doesn't help.
	*
	* The issue is tracked at:
	* http://code.google.com/p/chromium/issues/detail?id=114865
	*
	* When the workaround is enabled we will use the glBufferData / glBufferSubData
	* trick every 128 array buffer uploads.
	*
	* Hopefully we will understand this better and have a cleaner fix or get a
	* OS/driver level fix.
	*/
	#define GR_GL_MAC_BUFFER_OBJECT_PERFOMANCE_WORKAROUND \
	(GR_MAC_BUILD && \
	!GR_GL_USE_BUFFER_DATA_NULL_HINT)

	#endif