michael@0: 
michael@0: /*
michael@0:  * Copyright 2011 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: 
michael@0: #ifndef GrGLConfig_DEFINED
michael@0: #define GrGLConfig_DEFINED
michael@0: 
michael@0: #include "GrTypes.h"
michael@0: 
michael@0: /**
michael@0:  * Optional GL config file.
michael@0:  */
michael@0: #ifdef GR_GL_CUSTOM_SETUP_HEADER
michael@0:     #include GR_GL_CUSTOM_SETUP_HEADER
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_FUNCTION_TYPE)
michael@0:     #define GR_GL_FUNCTION_TYPE
michael@0: #endif
michael@0: 
michael@0: /**
michael@0:  * The following are optional defines that can be enabled at the compiler
michael@0:  * command line, in a IDE project, in a GrUserConfig.h file, or in a GL custom
michael@0:  * file (if one is in use). If a GR_GL_CUSTOM_SETUP_HEADER is used they can
michael@0:  * also be placed there.
michael@0:  *
michael@0:  * GR_GL_LOG_CALLS: if 1 Gr can print every GL call using GrPrintf. Defaults to
michael@0:  * 0. Logging can be enabled and disabled at runtime using a debugger via to
michael@0:  * global gLogCallsGL. The initial value of gLogCallsGL is controlled by
michael@0:  * GR_GL_LOG_CALLS_START.
michael@0:  *
michael@0:  * GR_GL_LOG_CALLS_START: controls the initial value of gLogCallsGL when
michael@0:  * GR_GL_LOG_CALLS is 1. Defaults to 0.
michael@0:  *
michael@0:  * GR_GL_CHECK_ERROR: if enabled Gr can do a glGetError() after every GL call.
michael@0:  * Defaults to 1 if SK_DEBUG is set, otherwise 0. When GR_GL_CHECK_ERROR is 1
michael@0:  * this can be toggled in a debugger using the gCheckErrorGL global. The initial
michael@0:  * value of gCheckErrorGL is controlled by by GR_GL_CHECK_ERROR_START.
michael@0:  *
michael@0:  * GR_GL_CHECK_ERROR_START: controls the initial value of gCheckErrorGL
michael@0:  * when GR_GL_CHECK_ERROR is 1.  Defaults to 1.
michael@0:  *
michael@0:  * GR_GL_NO_CONSTANT_ATTRIBUTES: if this evaluates to true then the GL backend
michael@0:  * will use uniforms instead of attributes in all cases when there is not
michael@0:  * per-vertex data. This is important when the underlying GL implementation
michael@0:  * doesn't actually support immediate style attribute values (e.g. when
michael@0:  * the GL stream is converted to DX as in ANGLE on Chrome). Defaults to 0.
michael@0:  *
michael@0:  * GR_GL_USE_BUFFER_DATA_NULL_HINT: When specifing new data for a vertex/index
michael@0:  * buffer that replaces old data Ganesh can give a hint to the driver that the
michael@0:  * previous data will not be used in future draws like this:
michael@0:  *  glBufferData(GL_..._BUFFER, size, NULL, usage);       //<--hint, NULL means
michael@0:  *  glBufferSubData(GL_..._BUFFER, 0, lessThanSize, data) //   old data can't be
michael@0:  *                                                        //   used again.
michael@0:  * However, this can be an unoptimization on some platforms, esp. Chrome.
michael@0:  * Chrome's cmd buffer will create a new allocation and memset the whole thing
michael@0:  * to zero (for security reasons). Defaults to 1 (enabled).
michael@0:  *
michael@0:  * GR_GL_PER_GL_FUNC_CALLBACK: When set to 1 the GrGLInterface object provides
michael@0:  * a function pointer that is called just before every gl function. The ptr must
michael@0:  * be valid (i.e. there is no NULL check). However, by default the callback will
michael@0:  * be set to a function that does nothing. The signature of the function is:
michael@0:  *    void function(const GrGLInterface*)
michael@0:  * It is not extern "C".
michael@0:  * The GrGLInterface field fCallback specifies the function ptr and there is an
michael@0:  * additional field fCallbackData of type intptr_t for client data.
michael@0:  *
michael@0:  * GR_GL_RGBA_8888_PIXEL_OPS_SLOW: Set this to 1 if it is known that performing
michael@0:  * glReadPixels / glTex(Sub)Image with format=GL_RGBA, type=GL_UNISIGNED_BYTE is
michael@0:  * significantly slower than format=GL_BGRA, type=GL_UNISIGNED_BYTE.
michael@0:  *
michael@0:  * GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL: Set this to 1 if calling
michael@0:  * glReadPixels to read the entire framebuffer is faster than calling it with
michael@0:  * the same sized rectangle but with a framebuffer bound that is larger than
michael@0:  * the rectangle read.
michael@0:  *
michael@0:  * GR_GL_CHECK_ALLOC_WITH_GET_ERROR: If set to 1 this will then glTexImage,
michael@0:  * glBufferData, glRenderbufferStorage, etc will be checked for errors. This
michael@0:  * amounts to ensuring the error is GL_NO_ERROR, calling the allocating
michael@0:  * function, and then checking that the error is still GL_NO_ERROR. When the
michael@0:  * value is 0 we will assume no error was generated without checking.
michael@0:  *
michael@0:  * GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT: We will normally check the FBO status
michael@0:  * every time we bind a texture or renderbuffer to an FBO. However, in some
michael@0:  * environments CheckFrameBufferStatus is very expensive. If this is set we will
michael@0:  * check the first time we use a color format or a combination of color /
michael@0:  * stencil formats as attachments. If the FBO is complete we will assume
michael@0:  * subsequent attachments with the same formats are complete as well.
michael@0:  *
michael@0:  * GR_GL_MUST_USE_VBO: Indicates that all vertices and indices must be rendered
michael@0:  * from VBOs. Chromium's command buffer doesn't allow glVertexAttribArray with
michael@0:  * ARARY_BUFFER 0 bound or glDrawElements with ELEMENT_ARRAY_BUFFER 0 bound.
michael@0:  *
michael@0:  * GR_GL_USE_NEW_SHADER_SOURCE_SIGNATURE is for compatibility with the new version
michael@0:  * of the OpenGLES2.0 headers from Khronos.  glShaderSource now takes a const char * const *,
michael@0:  * instead of a const char
michael@0:  */
michael@0: 
michael@0: #if !defined(GR_GL_LOG_CALLS)
michael@0:     #ifdef SK_DEBUG
michael@0:         #define GR_GL_LOG_CALLS 1
michael@0:     #else
michael@0:         #define GR_GL_LOG_CALLS 0
michael@0:     #endif
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_LOG_CALLS_START)
michael@0:     #define GR_GL_LOG_CALLS_START                       0
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_CHECK_ERROR)
michael@0:     #ifdef SK_DEBUG
michael@0:         #define GR_GL_CHECK_ERROR 1
michael@0:     #else
michael@0:         #define GR_GL_CHECK_ERROR 0
michael@0:     #endif
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_CHECK_ERROR_START)
michael@0:     #define GR_GL_CHECK_ERROR_START                     1
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_NO_CONSTANT_ATTRIBUTES)
michael@0:     #define GR_GL_NO_CONSTANT_ATTRIBUTES                0
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_USE_BUFFER_DATA_NULL_HINT)
michael@0:     #define GR_GL_USE_BUFFER_DATA_NULL_HINT             1
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_PER_GL_FUNC_CALLBACK)
michael@0:     #define GR_GL_PER_GL_FUNC_CALLBACK                  0
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_RGBA_8888_PIXEL_OPS_SLOW)
michael@0:     #define GR_GL_RGBA_8888_PIXEL_OPS_SLOW              0
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL)
michael@0:     #define GR_GL_FULL_READPIXELS_FASTER_THAN_PARTIAL   0
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_CHECK_ALLOC_WITH_GET_ERROR)
michael@0:     #define GR_GL_CHECK_ALLOC_WITH_GET_ERROR            1
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT)
michael@0:     #define GR_GL_CHECK_FBO_STATUS_ONCE_PER_FORMAT      0
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_MUST_USE_VBO)
michael@0:     #define GR_GL_MUST_USE_VBO                          0
michael@0: #endif
michael@0: 
michael@0: #if !defined(GR_GL_USE_NEW_SHADER_SOURCE_SIGNATURE)
michael@0:     #define GR_GL_USE_NEW_SHADER_SOURCE_SIGNATURE       0
michael@0: #endif
michael@0: 
michael@0: /**
michael@0:  * There is a strange bug that occurs on Macs with NVIDIA GPUs. We don't
michael@0:  * fully understand it. When (element) array buffers are continually
michael@0:  * respecified using glBufferData performance can fall off of a cliff. The
michael@0:  * driver winds up performing many DMA mapping / unmappings and chews up ~50% of
michael@0:  * the core. However, it has been observed that occaisonally respecifiying the
michael@0:  * buffer using glBufferData and then writing data using glBufferSubData
michael@0:  * prevents the bad behavior.
michael@0:  *
michael@0:  * There is a lot of uncertainty around this issue. In Chrome backgrounding
michael@0:  * the tab somehow initiates this behavior and we don't know what the connection
michael@0:  * is. Another observation is that Chrome's cmd buffer server will actually
michael@0:  * create a buffer full of zeros when it sees a NULL data param (for security
michael@0:  * reasons). If this is disabled and NULL is actually passed all the way to the
michael@0:  * driver then the workaround doesn't help.
michael@0:  *
michael@0:  * The issue is tracked at:
michael@0:  * http://code.google.com/p/chromium/issues/detail?id=114865
michael@0:  *
michael@0:  * When the workaround is enabled we will use the glBufferData / glBufferSubData
michael@0:  * trick every 128 array buffer uploads.
michael@0:  *
michael@0:  * Hopefully we will understand this better and have a cleaner fix or get a
michael@0:  * OS/driver level fix.
michael@0:  */
michael@0: #define GR_GL_MAC_BUFFER_OBJECT_PERFOMANCE_WORKAROUND   \
michael@0:     (defined(SK_BUILD_FOR_MAC) &&                       \
michael@0:      !GR_GL_USE_BUFFER_DATA_NULL_HINT)
michael@0: 
michael@0: #endif