QGLFunctions Class

The QGLFunctions class provides cross-platform access to the OpenGL ES 2.0 API. More...

Header: #include <QGLFunctions>
qmake: QT += opengl
Since: Qt 4.8

This class is obsolete. It is provided to keep old source code working. We strongly advise against using it in new code.

Public Types

enum OpenGLFeature { Multitexture, Shaders, Buffers, Framebuffers, ..., NPOTTextures }
flags OpenGLFeatures

Public Functions

QGLFunctions()
QGLFunctions(const QGLContext *context)
~QGLFunctions()
void glActiveTexture(GLenum texture)
void glAttachShader(GLuint program, GLuint shader)
void glBindAttribLocation(GLuint program, GLuint index, const char *name)
void glBindBuffer(GLenum target, GLuint buffer)
void glBindFramebuffer(GLenum target, GLuint framebuffer)
void glBindRenderbuffer(GLenum target, GLuint renderbuffer)
void glBlendColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha)
void glBlendEquation(GLenum mode)
void glBlendEquationSeparate(GLenum modeRGB, GLenum modeAlpha)
void glBlendFuncSeparate(GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha)
void glBufferData(GLenum target, qopengl_GLsizeiptr size, const void *data, GLenum usage)
void glBufferSubData(GLenum target, qopengl_GLintptr offset, qopengl_GLsizeiptr size, const void *data)
GLenum glCheckFramebufferStatus(GLenum target)
void glClearDepthf(GLclampf depth)
void glCompileShader(GLuint shader)
void glCompressedTexImage2D(GLenum target, GLint level, GLenum internalformat, GLsizei width, GLsizei height, GLint border, GLsizei imageSize, const void *data)
void glCompressedTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLsizei imageSize, const void *data)
GLuint glCreateProgram()
GLuint glCreateShader(GLenum type)
void glDeleteBuffers(GLsizei n, const GLuint *buffers)
void glDeleteFramebuffers(GLsizei n, const GLuint *framebuffers)
void glDeleteProgram(GLuint program)
void glDeleteRenderbuffers(GLsizei n, const GLuint *renderbuffers)
void glDeleteShader(GLuint shader)
void glDepthRangef(GLclampf zNear, GLclampf zFar)
void glDetachShader(GLuint program, GLuint shader)
void glDisableVertexAttribArray(GLuint index)
void glEnableVertexAttribArray(GLuint index)
void glFramebufferRenderbuffer(GLenum target, GLenum attachment, GLenum renderbuffertarget, GLuint renderbuffer)
void glFramebufferTexture2D(GLenum target, GLenum attachment, GLenum textarget, GLuint texture, GLint level)
void glGenBuffers(GLsizei n, GLuint *buffers)
void glGenFramebuffers(GLsizei n, GLuint *framebuffers)
void glGenRenderbuffers(GLsizei n, GLuint *renderbuffers)
void glGenerateMipmap(GLenum target)
void glGetActiveAttrib(GLuint program, GLuint index, GLsizei bufsize, GLsizei *length, GLint *size, GLenum *type, char *name)
void glGetActiveUniform(GLuint program, GLuint index, GLsizei bufsize, GLsizei *length, GLint *size, GLenum *type, char *name)
void glGetAttachedShaders(GLuint program, GLsizei maxcount, GLsizei *count, GLuint *shaders)
int glGetAttribLocation(GLuint program, const char *name)
void glGetBufferParameteriv(GLenum target, GLenum pname, GLint *params)
void glGetFramebufferAttachmentParameteriv(GLenum target, GLenum attachment, GLenum pname, GLint *params)
void glGetProgramInfoLog(GLuint program, GLsizei bufsize, GLsizei *length, char *infolog)
void glGetProgramiv(GLuint program, GLenum pname, GLint *params)
void glGetRenderbufferParameteriv(GLenum target, GLenum pname, GLint *params)
void glGetShaderInfoLog(GLuint shader, GLsizei bufsize, GLsizei *length, char *infolog)
void glGetShaderPrecisionFormat(GLenum shadertype, GLenum precisiontype, GLint *range, GLint *precision)
void glGetShaderSource(GLuint shader, GLsizei bufsize, GLsizei *length, char *source)
void glGetShaderiv(GLuint shader, GLenum pname, GLint *params)
int glGetUniformLocation(GLuint program, const char *name)
void glGetUniformfv(GLuint program, GLint location, GLfloat *params)
void glGetUniformiv(GLuint program, GLint location, GLint *params)
void glGetVertexAttribPointerv(GLuint index, GLenum pname, void **pointer)
void glGetVertexAttribfv(GLuint index, GLenum pname, GLfloat *params)
void glGetVertexAttribiv(GLuint index, GLenum pname, GLint *params)
GLboolean glIsBuffer(GLuint buffer)
GLboolean glIsFramebuffer(GLuint framebuffer)
GLboolean glIsProgram(GLuint program)
GLboolean glIsRenderbuffer(GLuint renderbuffer)
GLboolean glIsShader(GLuint shader)
void glLinkProgram(GLuint program)
void glReleaseShaderCompiler()
void glRenderbufferStorage(GLenum target, GLenum internalformat, GLsizei width, GLsizei height)
void glSampleCoverage(GLclampf value, GLboolean invert)
void glShaderBinary(GLint n, const GLuint *shaders, GLenum binaryformat, const void *binary, GLint length)
void glShaderSource(GLuint shader, GLsizei count, const char **string, const GLint *length)
void glStencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask)
void glStencilMaskSeparate(GLenum face, GLuint mask)
void glStencilOpSeparate(GLenum face, GLenum fail, GLenum zfail, GLenum zpass)
void glUniform1f(GLint location, GLfloat x)
void glUniform1fv(GLint location, GLsizei count, const GLfloat *v)
void glUniform1i(GLint location, GLint x)
void glUniform1iv(GLint location, GLsizei count, const GLint *v)
void glUniform2f(GLint location, GLfloat x, GLfloat y)
void glUniform2fv(GLint location, GLsizei count, const GLfloat *v)
void glUniform2i(GLint location, GLint x, GLint y)
void glUniform2iv(GLint location, GLsizei count, const GLint *v)
void glUniform3f(GLint location, GLfloat x, GLfloat y, GLfloat z)
void glUniform3fv(GLint location, GLsizei count, const GLfloat *v)
void glUniform3i(GLint location, GLint x, GLint y, GLint z)
void glUniform3iv(GLint location, GLsizei count, const GLint *v)
void glUniform4f(GLint location, GLfloat x, GLfloat y, GLfloat z, GLfloat w)
void glUniform4fv(GLint location, GLsizei count, const GLfloat *v)
void glUniform4i(GLint location, GLint x, GLint y, GLint z, GLint w)
void glUniform4iv(GLint location, GLsizei count, const GLint *v)
void glUniformMatrix2fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
void glUniformMatrix3fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
void glUniformMatrix4fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)
void glUseProgram(GLuint program)
void glValidateProgram(GLuint program)
void glVertexAttrib1f(GLuint indx, GLfloat x)
void glVertexAttrib1fv(GLuint indx, const GLfloat *values)
void glVertexAttrib2f(GLuint indx, GLfloat x, GLfloat y)
void glVertexAttrib2fv(GLuint indx, const GLfloat *values)
void glVertexAttrib3f(GLuint indx, GLfloat x, GLfloat y, GLfloat z)
void glVertexAttrib3fv(GLuint indx, const GLfloat *values)
void glVertexAttrib4f(GLuint indx, GLfloat x, GLfloat y, GLfloat z, GLfloat w)
void glVertexAttrib4fv(GLuint indx, const GLfloat *values)
void glVertexAttribPointer(GLuint indx, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *ptr)
bool hasOpenGLFeature(QGLFunctions::OpenGLFeature feature) const
void initializeGLFunctions(const QGLContext *context = nullptr)
QGLFunctions::OpenGLFeatures openGLFeatures() const

Detailed Description

The QGLFunctions class provides cross-platform access to the OpenGL ES 2.0 API.

OpenGL ES 2.0 defines a subset of the OpenGL specification that is common across many desktop and embedded OpenGL implementations. However, it can be difficult to use the functions from that subset because they need to be resolved manually on desktop systems.

QGLFunctions provides a guaranteed API that is available on all OpenGL systems and takes care of function resolution on systems that need it. The recommended way to use QGLFunctions is by direct inheritance:


  class MyGLWidget : public QGLWidget, protected QGLFunctions
  {
      Q_OBJECT
  public:
      MyGLWidget(QWidget *parent = 0) : QGLWidget(parent) {}

  protected:
      void initializeGL();
      void paintGL();
  };

  void MyGLWidget::initializeGL()
  {
      initializeGLFunctions();
  }

The paintGL() function can then use any of the OpenGL ES 2.0 functions without explicit resolution, such as glActiveTexture() in the following example:


  void MyGLWidget::paintGL()
  {
      glActiveTexture(GL_TEXTURE1);
      glBindTexture(GL_TEXTURE_2D, textureId);
      ...
  }

QGLFunctions can also be used directly for ad-hoc invocation of OpenGL ES 2.0 functions on all platforms:


  QGLFunctions glFuncs(QGLContext::currentContext());
  glFuncs.glActiveTexture(GL_TEXTURE1);

QGLFunctions provides wrappers for all OpenGL ES 2.0 functions, except those like glDrawArrays(), glViewport(), and glBindTexture() that don't have portability issues.

Including the header for QGLFunctions will also define all of the OpenGL ES 2.0 macro constants that are not already defined by the system's OpenGL headers, such as GL_TEXTURE1 above.

The hasOpenGLFeature() and openGLFeatures() functions can be used to determine if the OpenGL implementation has a major OpenGL ES 2.0 feature. For example, the following checks if non power of two textures are available:


  QGLFunctions funcs(QGLContext::currentContext());
  bool npot = funcs.hasOpenGLFeature(QGLFunctions::NPOTTextures);

Note: This class has been deprecated in favor of QOpenGLFunctions.

Member Type Documentation

enum QGLFunctions::OpenGLFeature
flags QGLFunctions::OpenGLFeatures

This enum defines OpenGL ES 2.0 features that may be optional on other platforms.

ConstantValueDescription
QGLFunctions::Multitexture0x0001glActiveTexture() function is available.
QGLFunctions::Shaders0x0002Shader functions are available.
QGLFunctions::Buffers0x0004Vertex and index buffer functions are available.
QGLFunctions::Framebuffers0x0008Framebuffer object functions are available.
QGLFunctions::BlendColor0x0010glBlendColor() is available.
QGLFunctions::BlendEquation0x0020glBlendEquation() is available.
QGLFunctions::BlendEquationSeparate0x0040glBlendEquationSeparate() is available.
QGLFunctions::BlendFuncSeparate0x0080glBlendFuncSeparate() is available.
QGLFunctions::BlendSubtract0x0100Blend subtract mode is available.
QGLFunctions::CompressedTextures0x0200Compressed texture functions are available.
QGLFunctions::Multisample0x0400glSampleCoverage() function is available.
QGLFunctions::StencilSeparate0x0800Separate stencil functions are available.
QGLFunctions::NPOTTextures0x1000Non power of two textures are available.

The OpenGLFeatures type is a typedef for QFlags<OpenGLFeature>. It stores an OR combination of OpenGLFeature values.

Member Function Documentation

QGLFunctions::QGLFunctions()

Constructs a default function resolver. The resolver cannot be used until initializeGLFunctions() is called to specify the context.

See also initializeGLFunctions().

QGLFunctions::QGLFunctions(const QGLContext *context)

Constructs a function resolver for context. If context is null, then the resolver will be created for the current QGLContext.

An object constructed in this way can only be used with context and other contexts that share with it. Use initializeGLFunctions() to change the object's context association.

See also initializeGLFunctions().

QGLFunctions::~QGLFunctions()

Destroys the instance of QGLFunctions.

void QGLFunctions::glActiveTexture(GLenum texture)

void QGLFunctions::glAttachShader(GLuint program, GLuint shader)

void QGLFunctions::glBindAttribLocation(GLuint program, GLuint index, const char *name)

void QGLFunctions::glBindBuffer(GLenum target, GLuint buffer)

void QGLFunctions::glBindFramebuffer(GLenum target, GLuint framebuffer)

void QGLFunctions::glBindRenderbuffer(GLenum target, GLuint renderbuffer)

void QGLFunctions::glBlendColor(GLclampf red, GLclampf green, GLclampf blue, GLclampf alpha)

void QGLFunctions::glBlendEquation(GLenum mode)

void QGLFunctions::glBlendEquationSeparate(GLenum modeRGB, GLenum modeAlpha)

void QGLFunctions::glBlendFuncSeparate(GLenum srcRGB, GLenum dstRGB, GLenum srcAlpha, GLenum dstAlpha)

void QGLFunctions::glBufferData(GLenum target, qopengl_GLsizeiptr size, const void *data, GLenum usage)

void QGLFunctions::glBufferSubData(GLenum target, qopengl_GLintptr offset, qopengl_GLsizeiptr size, const void *data)

GLenum QGLFunctions::glCheckFramebufferStatus(GLenum target)

void QGLFunctions::glClearDepthf(GLclampf depth)

void QGLFunctions::glCompileShader(GLuint shader)

void QGLFunctions::glCompressedTexImage2D(GLenum target, GLint level, GLenum internalformat, GLsizei width, GLsizei height, GLint border, GLsizei imageSize, const void *data)

void QGLFunctions::glCompressedTexSubImage2D(GLenum target, GLint level, GLint xoffset, GLint yoffset, GLsizei width, GLsizei height, GLenum format, GLsizei imageSize, const void *data)

GLuint QGLFunctions::glCreateProgram()

GLuint QGLFunctions::glCreateShader(GLenum type)

void QGLFunctions::glDeleteBuffers(GLsizei n, const GLuint *buffers)

void QGLFunctions::glDeleteFramebuffers(GLsizei n, const GLuint *framebuffers)

void QGLFunctions::glDeleteProgram(GLuint program)

void QGLFunctions::glDeleteRenderbuffers(GLsizei n, const GLuint *renderbuffers)

void QGLFunctions::glDeleteShader(GLuint shader)

void QGLFunctions::glDepthRangef(GLclampf zNear, GLclampf zFar)

void QGLFunctions::glDetachShader(GLuint program, GLuint shader)

void QGLFunctions::glDisableVertexAttribArray(GLuint index)

void QGLFunctions::glEnableVertexAttribArray(GLuint index)

void QGLFunctions::glFramebufferRenderbuffer(GLenum target, GLenum attachment, GLenum renderbuffertarget, GLuint renderbuffer)

void QGLFunctions::glFramebufferTexture2D(GLenum target, GLenum attachment, GLenum textarget, GLuint texture, GLint level)

void QGLFunctions::glGenBuffers(GLsizei n, GLuint *buffers)

void QGLFunctions::glGenFramebuffers(GLsizei n, GLuint *framebuffers)

void QGLFunctions::glGenRenderbuffers(GLsizei n, GLuint *renderbuffers)

void QGLFunctions::glGenerateMipmap(GLenum target)

void QGLFunctions::glGetActiveAttrib(GLuint program, GLuint index, GLsizei bufsize, GLsizei *length, GLint *size, GLenum *type, char *name)

void QGLFunctions::glGetActiveUniform(GLuint program, GLuint index, GLsizei bufsize, GLsizei *length, GLint *size, GLenum *type, char *name)

void QGLFunctions::glGetAttachedShaders(GLuint program, GLsizei maxcount, GLsizei *count, GLuint *shaders)

int QGLFunctions::glGetAttribLocation(GLuint program, const char *name)

void QGLFunctions::glGetBufferParameteriv(GLenum target, GLenum pname, GLint *params)

void QGLFunctions::glGetFramebufferAttachmentParameteriv(GLenum target, GLenum attachment, GLenum pname, GLint *params)

void QGLFunctions::glGetProgramInfoLog(GLuint program, GLsizei bufsize, GLsizei *length, char *infolog)

void QGLFunctions::glGetProgramiv(GLuint program, GLenum pname, GLint *params)

void QGLFunctions::glGetRenderbufferParameteriv(GLenum target, GLenum pname, GLint *params)

void QGLFunctions::glGetShaderInfoLog(GLuint shader, GLsizei bufsize, GLsizei *length, char *infolog)

void QGLFunctions::glGetShaderPrecisionFormat(GLenum shadertype, GLenum precisiontype, GLint *range, GLint *precision)

void QGLFunctions::glGetShaderSource(GLuint shader, GLsizei bufsize, GLsizei *length, char *source)

void QGLFunctions::glGetShaderiv(GLuint shader, GLenum pname, GLint *params)

int QGLFunctions::glGetUniformLocation(GLuint program, const char *name)

void QGLFunctions::glGetUniformfv(GLuint program, GLint location, GLfloat *params)

void QGLFunctions::glGetUniformiv(GLuint program, GLint location, GLint *params)

void QGLFunctions::glGetVertexAttribPointerv(GLuint index, GLenum pname, void **pointer)

void QGLFunctions::glGetVertexAttribfv(GLuint index, GLenum pname, GLfloat *params)

void QGLFunctions::glGetVertexAttribiv(GLuint index, GLenum pname, GLint *params)

GLboolean QGLFunctions::glIsBuffer(GLuint buffer)

GLboolean QGLFunctions::glIsFramebuffer(GLuint framebuffer)

GLboolean QGLFunctions::glIsProgram(GLuint program)

GLboolean QGLFunctions::glIsRenderbuffer(GLuint renderbuffer)

GLboolean QGLFunctions::glIsShader(GLuint shader)

void QGLFunctions::glLinkProgram(GLuint program)

void QGLFunctions::glReleaseShaderCompiler()

void QGLFunctions::glRenderbufferStorage(GLenum target, GLenum internalformat, GLsizei width, GLsizei height)

void QGLFunctions::glSampleCoverage(GLclampf value, GLboolean invert)

void QGLFunctions::glShaderBinary(GLint n, const GLuint *shaders, GLenum binaryformat, const void *binary, GLint length)

void QGLFunctions::glShaderSource(GLuint shader, GLsizei count, const char **string, const GLint *length)

void QGLFunctions::glStencilFuncSeparate(GLenum face, GLenum func, GLint ref, GLuint mask)

void QGLFunctions::glStencilMaskSeparate(GLenum face, GLuint mask)

void QGLFunctions::glStencilOpSeparate(GLenum face, GLenum fail, GLenum zfail, GLenum zpass)

void QGLFunctions::glUniform1f(GLint location, GLfloat x)

void QGLFunctions::glUniform1fv(GLint location, GLsizei count, const GLfloat *v)

void QGLFunctions::glUniform1i(GLint location, GLint x)

void QGLFunctions::glUniform1iv(GLint location, GLsizei count, const GLint *v)

void QGLFunctions::glUniform2f(GLint location, GLfloat x, GLfloat y)

void QGLFunctions::glUniform2fv(GLint location, GLsizei count, const GLfloat *v)

void QGLFunctions::glUniform2i(GLint location, GLint x, GLint y)

void QGLFunctions::glUniform2iv(GLint location, GLsizei count, const GLint *v)

void QGLFunctions::glUniform3f(GLint location, GLfloat x, GLfloat y, GLfloat z)

void QGLFunctions::glUniform3fv(GLint location, GLsizei count, const GLfloat *v)

void QGLFunctions::glUniform3i(GLint location, GLint x, GLint y, GLint z)

void QGLFunctions::glUniform3iv(GLint location, GLsizei count, const GLint *v)

void QGLFunctions::glUniform4f(GLint location, GLfloat x, GLfloat y, GLfloat z, GLfloat w)

void QGLFunctions::glUniform4fv(GLint location, GLsizei count, const GLfloat *v)

void QGLFunctions::glUniform4i(GLint location, GLint x, GLint y, GLint z, GLint w)

void QGLFunctions::glUniform4iv(GLint location, GLsizei count, const GLint *v)

void QGLFunctions::glUniformMatrix2fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)

void QGLFunctions::glUniformMatrix3fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)

void QGLFunctions::glUniformMatrix4fv(GLint location, GLsizei count, GLboolean transpose, const GLfloat *value)

void QGLFunctions::glUseProgram(GLuint program)

void QGLFunctions::glValidateProgram(GLuint program)

void QGLFunctions::glVertexAttrib1f(GLuint indx, GLfloat x)

void QGLFunctions::glVertexAttrib1fv(GLuint indx, const GLfloat *values)

void QGLFunctions::glVertexAttrib2f(GLuint indx, GLfloat x, GLfloat y)

void QGLFunctions::glVertexAttrib2fv(GLuint indx, const GLfloat *values)

void QGLFunctions::glVertexAttrib3f(GLuint indx, GLfloat x, GLfloat y, GLfloat z)

void QGLFunctions::glVertexAttrib3fv(GLuint indx, const GLfloat *values)

void QGLFunctions::glVertexAttrib4f(GLuint indx, GLfloat x, GLfloat y, GLfloat z, GLfloat w)

void QGLFunctions::glVertexAttrib4fv(GLuint indx, const GLfloat *values)

void QGLFunctions::glVertexAttribPointer(GLuint indx, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const void *ptr)

bool QGLFunctions::hasOpenGLFeature(QGLFunctions::OpenGLFeature feature) const

Returns true if feature is present on this system's OpenGL implementation; false otherwise.

It is assumed that the QGLContext associated with this function resolver is current.

See also openGLFeatures().

void QGLFunctions::initializeGLFunctions(const QGLContext *context = nullptr)

Initializes GL function resolution for context. If context is null, then the current QGLContext will be used.

After calling this function, the QGLFunctions object can only be used with context and other contexts that share with it. Call initializeGLFunctions() again to change the object's context association.

QGLFunctions::OpenGLFeatures QGLFunctions::openGLFeatures() const

Returns the set of features that are present on this system's OpenGL implementation.

It is assumed that the QGLContext associated with this function resolver is current.

See also hasOpenGLFeature().