//========================================================================
// GLFW - An OpenGL library
// Platform: Any
// API version: 3.0
// WWW: http://www.glfw.org/
//------------------------------------------------------------------------
// Copyright (c) 2002-2006 Marcus Geelnard
// Copyright (c) 2006-2010 Camilla Berglund <elmindreda@elmindreda.org>
//
// This software is provided 'as-is', without any express or implied
// warranty. In no event will the authors be held liable for any damages
// arising from the use of this software.
//
// Permission is granted to anyone to use this software for any purpose,
// including commercial applications, and to alter it and redistribute it
// freely, subject to the following restrictions:
//
// 1. The origin of this software must not be misrepresented; you must not
// claim that you wrote the original software. If you use this software
// in a product, an acknowledgment in the product documentation would
// be appreciated but is not required.
//
// 2. Altered source versions must be plainly marked as such, and must not
// be misrepresented as being the original software.
//
// 3. This notice may not be removed or altered from any source
// distribution.
//
//========================================================================
#include "internal.h"
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <stdio.h>
// Parses the client API version string and extracts the version number
//
static GLboolean parseGLVersion(int* api, int* major, int* minor, int* rev)
{
int i, _api = GLFW_OPENGL_API, _major, _minor = 0, _rev = 0;
const char* version;
const char* prefixes[] =
{
"OpenGL ES-CM ",
"OpenGL ES-CL ",
"OpenGL ES ",
NULL
};
version = (const char*) glGetString(GL_VERSION);
if (!version)
{
_glfwInputError(GLFW_PLATFORM_ERROR,
"Failed to retrieve context version string");
return GL_FALSE;
}
for (i = 0; prefixes[i]; i++)
{
const size_t length = strlen(prefixes[i]);
if (strncmp(version, prefixes[i], length) == 0)
{
version += length;
_api = GLFW_OPENGL_ES_API;
break;
}
}
if (!sscanf(version, "%d.%d.%d", &_major, &_minor, &_rev))
{
_glfwInputError(GLFW_PLATFORM_ERROR,
"No version found in context version string");
return GL_FALSE;
}
*api = _api;
*major = _major;
*minor = _minor;
*rev = _rev;
return GL_TRUE;
}
//////////////////////////////////////////////////////////////////////////
////// GLFW internal API //////
//////////////////////////////////////////////////////////////////////////
GLboolean _glfwIsValidContextConfig(_GLFWwndconfig* wndconfig)
{
if (wndconfig->clientAPI != GLFW_OPENGL_API &&
wndconfig->clientAPI != GLFW_OPENGL_ES_API)
{
_glfwInputError(GLFW_INVALID_ENUM, "Invalid client API requested");
return GL_FALSE;
}
if (wndconfig->clientAPI == GLFW_OPENGL_API)
{
if (wndconfig->glMajor < 1 || wndconfig->glMinor < 0 ||
(wndconfig->glMajor == 1 && wndconfig->glMinor > 5) ||
(wndconfig->glMajor == 2 && wndconfig->glMinor > 1) ||
(wndconfig->glMajor == 3 && wndconfig->glMinor > 3))
{
// OpenGL 1.0 is the smallest valid version
// OpenGL 1.x series ended with version 1.5
// OpenGL 2.x series ended with version 2.1
// OpenGL 3.x series ended with version 3.3
_glfwInputError(GLFW_INVALID_VALUE,
"Invalid OpenGL version %i.%i requested",
wndconfig->glMajor, wndconfig->glMinor);
return GL_FALSE;
}
else
{
// For now, let everything else through
}
if (wndconfig->glProfile)
{
if (wndconfig->glProfile != GLFW_OPENGL_CORE_PROFILE &&
wndconfig->glProfile != GLFW_OPENGL_COMPAT_PROFILE)
{
_glfwInputError(GLFW_INVALID_ENUM,
"Invalid OpenGL profile requested");
return GL_FALSE;
}
if (wndconfig->glMajor < 3 ||
(wndconfig->glMajor == 3 && wndconfig->glMinor < 2))
{
// Desktop OpenGL context profiles are only defined for version 3.2
// and above
_glfwInputError(GLFW_INVALID_VALUE,
"Context profiles only exist for "
"OpenGL version 3.2 and above");
return GL_FALSE;
}
}
if (wndconfig->glForward && wndconfig->glMajor < 3)
{
// Forward-compatible contexts are only defined for OpenGL version 3.0 and above
_glfwInputError(GLFW_INVALID_VALUE,
"Forward compatibility only exist for OpenGL "
"version 3.0 and above");
return GL_FALSE;
}
}
else if (wndconfig->clientAPI == GLFW_OPENGL_ES_API)
{
if (wndconfig->glMajor < 1 || wndconfig->glMinor < 0 ||
(wndconfig->glMajor == 1 && wndconfig->glMinor > 1) ||
(wndconfig->glMajor == 2 && wndconfig->glMinor > 0))
{
// OpenGL ES 1.0 is the smallest valid version
// OpenGL ES 1.x series ended with version 1.1
// OpenGL ES 2.x series ended with version 2.0
_glfwInputError(GLFW_INVALID_VALUE,
"Invalid OpenGL ES version %i.%i requested",
wndconfig->glMajor, wndconfig->glMinor);
return GL_FALSE;
}
else
{
// For now, let everything else through
}
if (wndconfig->glProfile)
{
// OpenGL ES does not support profiles
_glfwInputError(GLFW_INVALID_VALUE,
"Context profiles are not supported by OpenGL ES");
return GL_FALSE;
}
if (wndconfig->glForward)
{
// OpenGL ES does not support forward-compatibility
_glfwInputError(GLFW_INVALID_VALUE,
"Forward compatibility is not supported by OpenGL ES");
return GL_FALSE;
}
}
if (wndconfig->glRobustness)
{
if (wndconfig->glRobustness != GLFW_NO_RESET_NOTIFICATION &&
wndconfig->glRobustness != GLFW_LOSE_CONTEXT_ON_RESET)
{
_glfwInputError(GLFW_INVALID_VALUE,
"Invalid context robustness mode requested");
return GL_FALSE;
}
}
return GL_TRUE;
}
const _GLFWfbconfig* _glfwChooseFBConfig(const _GLFWfbconfig* desired,
const _GLFWfbconfig* alternatives,
unsigned int count)
{
unsigned int i;
unsigned int missing, leastMissing = UINT_MAX;
unsigned int colorDiff, leastColorDiff = UINT_MAX;
unsigned int extraDiff, leastExtraDiff = UINT_MAX;
const _GLFWfbconfig* current;
const _GLFWfbconfig* closest = NULL;
for (i = 0; i < count; i++)
{
current = alternatives + i;
if (desired->stereo > 0 && current->stereo == 0)
{
// Stereo is a hard constraint
continue;
}
// Count number of missing buffers
{
missing = 0;
if (desired->alphaBits > 0 && current->alphaBits == 0)
missing++;
if (desired->depthBits > 0 && current->depthBits == 0)
missing++;
if (desired->stencilBits > 0 && current->stencilBits == 0)
missing++;
if (desired->auxBuffers > 0 && current->auxBuffers < desired->auxBuffers)
missing += desired->auxBuffers - current->auxBuffers;
if (desired->samples > 0 && current->samples == 0)
{
// Technically, several multisampling buffers could be
// involved, but that's a lower level implementation detail and
// not important to us here, so we count them as one
missing++;
}
}
// These polynomials make many small channel size differences matter
// less than one large channel size difference
// Calculate color channel size difference value
{
colorDiff = 0;
if (desired->redBits > 0)
{
colorDiff += (desired->redBits - current->redBits) *
(desired->redBits - current->redBits);
}
if (desired->greenBits > 0)
{
colorDiff += (desired->greenBits - current->greenBits) *
(desired->greenBits - current->greenBits);
}
if (desired->blueBits > 0)
{
colorDiff += (desired->blueBits - current->blueBits) *
(desired->blueBits - current->blueBits);
}
}
// Calculate non-color channel size difference value
{
extraDiff = 0;
if (desired->alphaBits > 0)
{
extraDiff += (desired->alphaBits - current->alphaBits) *
(desired->alphaBits - current->alphaBits);
}
if (desired->depthBits > 0)
{
extraDiff += (desired->depthBits - current->depthBits) *
(desired->depthBits - current->depthBits);
}
if (desired->stencilBits > 0)
{
extraDiff += (desired->stencilBits - current->stencilBits) *
(desired->stencilBits - current->stencilBits);
}
if (desired->accumRedBits > 0)
{
extraDiff += (desired->accumRedBits - current->accumRedBits) *
(desired->accumRedBits - current->accumRedBits);
}
if (desired->accumGreenBits > 0)
{
extraDiff += (desired->accumGreenBits - current->accumGreenBits) *
(desired->accumGreenBits - current->accumGreenBits);
}
if (desired->accumBlueBits > 0)
{
extraDiff += (desired->accumBlueBits - current->accumBlueBits) *
(desired->accumBlueBits - current->accumBlueBits);
}
if (desired->accumAlphaBits > 0)
{
extraDiff += (desired->accumAlphaBits - current->accumAlphaBits) *
(desired->accumAlphaBits - current->accumAlphaBits);
}
if (desired->samples > 0)
{
extraDiff += (desired->samples - current->samples) *
(desired->samples - current->samples);
}
if (desired->sRGB)
{
if (!current->sRGB)
extraDiff++;
}
}
// Figure out if the current one is better than the best one found so far
// Least number of missing buffers is the most important heuristic,
// then color buffer size match and lastly size match for other buffers
if (missing < leastMissing)
closest = current;
else if (missing == leastMissing)
{
if ((colorDiff < leastColorDiff) ||
(colorDiff == leastColorDiff && extraDiff < leastExtraDiff))
{
closest = current;
}
}
if (current == closest)
{
leastMissing = missing;
leastColorDiff = colorDiff;
leastExtraDiff = extraDiff;
}
}
return closest;
}
GLboolean _glfwRefreshContextAttribs(void)
{
_GLFWwindow* window = _glfwPlatformGetCurrentContext();
if (!parseGLVersion(&window->clientAPI,
&window->glMajor,
&window->glMinor,
&window->glRevision))
{
return GL_FALSE;
}
#if defined(_GLFW_USE_OPENGL)
if (window->glMajor > 2)
{
// OpenGL 3.0+ uses a different function for extension string retrieval
// We cache it here instead of in glfwExtensionSupported mostly to alert
// users as early as possible that their build may be broken
window->GetStringi = (PFNGLGETSTRINGIPROC) glfwGetProcAddress("glGetStringi");
if (!window->GetStringi)
{
_glfwInputError(GLFW_PLATFORM_ERROR,
"Entry point retrieval is broken");
return GL_FALSE;
}
}
if (window->clientAPI == GLFW_OPENGL_API)
{
// Read back context flags (OpenGL 3.0 and above)
if (window->glMajor >= 3)
{
GLint flags;
glGetIntegerv(GL_CONTEXT_FLAGS, &flags);
if (flags & GL_CONTEXT_FLAG_FORWARD_COMPATIBLE_BIT)
window->glForward = GL_TRUE;
if (flags & GL_CONTEXT_FLAG_DEBUG_BIT)
window->glDebug = GL_TRUE;
else if (glfwExtensionSupported("GL_ARB_debug_output"))
{
// HACK: This is a workaround for older drivers (pre KHR_debug)
// not setting the debug bit in the context flags for debug
// contexts
window->glDebug = GL_TRUE;
}
}
// Read back OpenGL context profile (OpenGL 3.2 and above)
if (window->glMajor > 3 ||
(window->glMajor == 3 && window->glMinor >= 2))
{
GLint mask;
glGetIntegerv(GL_CONTEXT_PROFILE_MASK, &mask);
if (mask & GL_CONTEXT_COMPATIBILITY_PROFILE_BIT)
window->glProfile = GLFW_OPENGL_COMPAT_PROFILE;
else if (mask & GL_CONTEXT_CORE_PROFILE_BIT)
window->glProfile = GLFW_OPENGL_CORE_PROFILE;
}
// Read back robustness strategy
if (glfwExtensionSupported("GL_ARB_robustness"))
{
// NOTE: We avoid using the context flags for detection, as they are
// only present from 3.0 while the extension applies from 1.1
GLint strategy;
glGetIntegerv(GL_RESET_NOTIFICATION_STRATEGY_ARB, &strategy);
if (strategy == GL_LOSE_CONTEXT_ON_RESET_ARB)
window->glRobustness = GLFW_LOSE_CONTEXT_ON_RESET;
else if (strategy == GL_NO_RESET_NOTIFICATION_ARB)
window->glRobustness = GLFW_NO_RESET_NOTIFICATION;
}
}
else
{
// Read back robustness strategy
if (glfwExtensionSupported("GL_EXT_robustness"))
{
// NOTE: The values of these constants match those of the OpenGL ARB
// one, so we can reuse them here
GLint strategy;
glGetIntegerv(GL_RESET_NOTIFICATION_STRATEGY_ARB, &strategy);
if (strategy == GL_LOSE_CONTEXT_ON_RESET_ARB)
window->glRobustness = GLFW_LOSE_CONTEXT_ON_RESET;
else if (strategy == GL_NO_RESET_NOTIFICATION_ARB)
window->glRobustness = GLFW_NO_RESET_NOTIFICATION;
}
}
#endif // _GLFW_USE_OPENGL
return GL_TRUE;
}
GLboolean _glfwIsValidContext(_GLFWwndconfig* wndconfig)
{
_GLFWwindow* window = _glfwPlatformGetCurrentContext();
if (window->glMajor < wndconfig->glMajor ||
(window->glMajor == wndconfig->glMajor &&
window->glMinor < wndconfig->glMinor))
{
// The desired OpenGL version is greater than the actual version
// This only happens if the machine lacks {GLX|WGL}_ARB_create_context
// /and/ the user has requested an OpenGL version greater than 1.0
// For API consistency, we emulate the behavior of the
// {GLX|WGL}_ARB_create_context extension and fail here
_glfwInputError(GLFW_VERSION_UNAVAILABLE, NULL);
return GL_FALSE;
}
return GL_TRUE;
}
int _glfwStringInExtensionString(const char* string, const GLubyte* extensions)
{
const GLubyte* start;
GLubyte* where;
GLubyte* terminator;
// It takes a bit of care to be fool-proof about parsing the
// OpenGL extensions string. Don't be fooled by sub-strings,
// etc.
start = extensions;
for (;;)
{
where = (GLubyte*) strstr((const char*) start, string);
if (!where)
return GL_FALSE;
terminator = where + strlen(string);
if (where == start || *(where - 1) == ' ')
{
if (*terminator == ' ' || *terminator == '\0')
break;
}
start = terminator;
}
return GL_TRUE;
}
//////////////////////////////////////////////////////////////////////////
////// GLFW public API //////
//////////////////////////////////////////////////////////////////////////
GLFWAPI void glfwMakeContextCurrent(GLFWwindow* handle)
{
_GLFWwindow* window = (_GLFWwindow*) handle;
_GLFW_REQUIRE_INIT();
if (_glfwPlatformGetCurrentContext() == window)
return;
_glfwPlatformMakeContextCurrent(window);
}
GLFWAPI GLFWwindow* glfwGetCurrentContext(void)
{
_GLFW_REQUIRE_INIT_OR_RETURN(NULL);
return (GLFWwindow*) _glfwPlatformGetCurrentContext();
}
GLFWAPI void glfwSwapBuffers(GLFWwindow* handle)
{
_GLFWwindow* window = (_GLFWwindow*) handle;
_GLFW_REQUIRE_INIT();
_glfwPlatformSwapBuffers(window);
}
GLFWAPI void glfwSwapInterval(int interval)
{
_GLFW_REQUIRE_INIT();
if (!_glfwPlatformGetCurrentContext())
{
_glfwInputError(GLFW_NO_CURRENT_CONTEXT, NULL);
return;
}
_glfwPlatformSwapInterval(interval);
}
GLFWAPI int glfwExtensionSupported(const char* extension)
{
const GLubyte* extensions;
_GLFWwindow* window;
_GLFW_REQUIRE_INIT_OR_RETURN(GL_FALSE);
window = _glfwPlatformGetCurrentContext();
if (!window)
{
_glfwInputError(GLFW_NO_CURRENT_CONTEXT, NULL);
return GL_FALSE;
}
if (extension == NULL || *extension == '\0')
{
_glfwInputError(GLFW_INVALID_VALUE, NULL);
return GL_FALSE;
}
if (window->glMajor < 3)
{
// Check if extension is in the old style OpenGL extensions string
extensions = glGetString(GL_EXTENSIONS);
if (extensions != NULL)
{
if (_glfwStringInExtensionString(extension, extensions))
return GL_TRUE;
}
}
#if defined(_GLFW_USE_OPENGL)
else
{
int i;
GLint count;
// Check if extension is in the modern OpenGL extensions string list
glGetIntegerv(GL_NUM_EXTENSIONS, &count);
for (i = 0; i < count; i++)
{
if (strcmp((const char*) window->GetStringi(GL_EXTENSIONS, i),
extension) == 0)
{
return GL_TRUE;
}
}
}
#endif // _GLFW_USE_OPENGL
// Check if extension is in the platform-specific string
return _glfwPlatformExtensionSupported(extension);
}
GLFWAPI GLFWglproc glfwGetProcAddress(const char* procname)
{
_GLFW_REQUIRE_INIT_OR_RETURN(NULL);
if (!_glfwPlatformGetCurrentContext())
{
_glfwInputError(GLFW_NO_CURRENT_CONTEXT, NULL);
return NULL;
}
return _glfwPlatformGetProcAddress(procname);
}