Add wrappers for glEnableVertexAttrib and glVertexAttrib*Pointer

Needed to work around QTBUG-43199 to be able to specify integer
vertex attributes such as joint indices.

Change-Id: I39ab83e881b6afb75467c76b56125917013b3bca
Reviewed-by: Sean Harmer <sean.harmer@kdab.com>

13 files changed, 216 insertions, 1 deletions

diff --git a/src/render/graphicshelpers/graphicshelperes2.cpp b/src/render/graphicshelpers/graphicshelperes2.cpp
index 200b749ee..0c4239dc9 100644
--- a/src/render/graphicshelpers/graphicshelperes2.cpp
+++ b/src/render/graphicshelpers/graphicshelperes2.cpp
@@ -249,6 +249,27 @@ void GraphicsHelperES2::vertexAttribDivisor(GLuint index, GLuint divisor)
     Q_UNUSED(divisor);
 }
 
+void GraphicsHelperES2::vertexAttributePointer(GLenum shaderDataType,
+                                               GLuint index,
+                                               GLint size,
+                                               GLenum type,
+                                               GLboolean normalized,
+                                               GLsizei stride,
+                                               const GLvoid *pointer)
+{
+    switch (shaderDataType) {
+    case GL_FLOAT:
+    case GL_FLOAT_VEC2:
+    case GL_FLOAT_VEC3:
+    case GL_FLOAT_VEC4:
+        m_funcs->glVertexAttribPointer(index, size, type, normalized, stride, pointer);
+        break;
+
+    default:
+        qCWarning(Render::Rendering) << "vertexAttribPointer: Unhandled type";
+    }
+}
+
 void GraphicsHelperES2::blendEquation(GLenum mode)
 {
     m_funcs->glBlendEquation(mode);
@@ -530,6 +551,11 @@ void GraphicsHelperES2::enablePrimitiveRestart(int)
 {
 }
 
+void GraphicsHelperES2::enableVertexAttributeArray(int location)
+{
+    m_funcs->glEnableVertexAttribArray(location);
+}
+
 void GraphicsHelperES2::disablePrimitiveRestart()
 {
 }
diff --git a/src/render/graphicshelpers/graphicshelperes2_p.h b/src/render/graphicshelpers/graphicshelperes2_p.h
index 28d58b368..d068b5307 100644
--- a/src/render/graphicshelpers/graphicshelperes2_p.h
+++ b/src/render/graphicshelpers/graphicshelperes2_p.h
@@ -106,6 +106,7 @@ public:
     void enableClipPlane(int clipPlane) Q_DECL_OVERRIDE;
     void enablei(GLenum cap, GLuint index) Q_DECL_OVERRIDE;
     void enablePrimitiveRestart(int primitiveRestartIndex) Q_DECL_OVERRIDE;
+    void enableVertexAttributeArray(int location) Q_DECL_OVERRIDE;
     void frontFace(GLenum mode) Q_DECL_OVERRIDE;
     QSize getRenderBufferDimensions(GLuint renderBufferId) Q_DECL_OVERRIDE;
     QSize getTextureDimensions(GLuint textureId, GLenum target, uint level = 0) Q_DECL_OVERRIDE;
@@ -127,6 +128,7 @@ public:
     uint uniformByteSize(const ShaderUniform &description) Q_DECL_OVERRIDE;
     void useProgram(GLuint programId) Q_DECL_OVERRIDE;
     void vertexAttribDivisor(GLuint index, GLuint divisor) Q_DECL_OVERRIDE;
+    void vertexAttributePointer(GLenum shaderDataType, GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid *pointer) Q_DECL_OVERRIDE;
 
     void glUniform1fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
     void glUniform2fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
diff --git a/src/render/graphicshelpers/graphicshelperes3.cpp b/src/render/graphicshelpers/graphicshelperes3.cpp
index 4c5ae4ec6..d970bcd74 100644
--- a/src/render/graphicshelpers/graphicshelperes3.cpp
+++ b/src/render/graphicshelpers/graphicshelperes3.cpp
@@ -184,6 +184,38 @@ void GraphicsHelperES3::vertexAttribDivisor(GLuint index, GLuint divisor)
     m_extraFuncs->glVertexAttribDivisor(index, divisor);
 }
 
+void GraphicsHelperES3::vertexAttributePointer(GLenum shaderDataType,
+                                               GLuint index,
+                                               GLint size,
+                                               GLenum type,
+                                               GLboolean normalized,
+                                               GLsizei stride,
+                                               const GLvoid *pointer)
+{
+    switch (shaderDataType) {
+    case GL_FLOAT:
+    case GL_FLOAT_VEC2:
+    case GL_FLOAT_VEC3:
+    case GL_FLOAT_VEC4:
+        m_funcs->glVertexAttribPointer(index, size, type, normalized, stride, pointer);
+        break;
+
+    case GL_INT:
+    case GL_INT_VEC2:
+    case GL_INT_VEC3:
+    case GL_INT_VEC4:
+    case GL_UNSIGNED_INT:
+    case GL_UNSIGNED_INT_VEC2:
+    case GL_UNSIGNED_INT_VEC3:
+    case GL_UNSIGNED_INT_VEC4:
+        m_extraFuncs->glVertexAttribIPointer(index, size, type, stride, pointer);
+        break;
+
+    default:
+        qCWarning(Render::Rendering) << "vertexAttribPointer: Unhandled type";
+    }
+}
+
 void GraphicsHelperES3::bindFrameBufferAttachment(QOpenGLTexture *texture, const Attachment &attachment)
 {
     GLenum attr = GL_COLOR_ATTACHMENT0;
diff --git a/src/render/graphicshelpers/graphicshelperes3_p.h b/src/render/graphicshelpers/graphicshelperes3_p.h
index 0b12a0509..7a460895f 100644
--- a/src/render/graphicshelpers/graphicshelperes3_p.h
+++ b/src/render/graphicshelpers/graphicshelperes3_p.h
@@ -80,6 +80,7 @@ public:
     bool supportsFeature(Feature feature) const Q_DECL_OVERRIDE;
     GLboolean unmapBuffer(GLenum target) Q_DECL_OVERRIDE;
     void vertexAttribDivisor(GLuint index, GLuint divisor) Q_DECL_OVERRIDE;
+    void vertexAttributePointer(GLenum shaderDataType, GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid *pointer) Q_DECL_OVERRIDE;
 
     UniformType uniformTypeFromGLType(GLenum glType) Q_DECL_OVERRIDE;
 
diff --git a/src/render/graphicshelpers/graphicshelpergl2.cpp b/src/render/graphicshelpers/graphicshelpergl2.cpp
index 6893760b1..ff16abc76 100644
--- a/src/render/graphicshelpers/graphicshelpergl2.cpp
+++ b/src/render/graphicshelpers/graphicshelpergl2.cpp
@@ -43,7 +43,7 @@
 #include <private/attachmentpack_p.h>
 #include <QtOpenGLExtensions/QOpenGLExtensions>
 #include <private/qgraphicsutils_p.h>
-#include <QDebug>
+#include <Qt3DRender/private/renderlogging_p.h>
 
 QT_BEGIN_NAMESPACE
 
@@ -227,6 +227,27 @@ void GraphicsHelperGL2::vertexAttribDivisor(GLuint index,
     Q_UNUSED(divisor);
 }
 
+void GraphicsHelperGL2::vertexAttributePointer(GLenum shaderDataType,
+                                               GLuint index,
+                                               GLint size,
+                                               GLenum type,
+                                               GLboolean normalized,
+                                               GLsizei stride,
+                                               const GLvoid *pointer)
+{
+    switch (shaderDataType) {
+    case GL_FLOAT:
+    case GL_FLOAT_VEC2:
+    case GL_FLOAT_VEC3:
+    case GL_FLOAT_VEC4:
+        m_funcs->glVertexAttribPointer(index, size, type, normalized, stride, pointer);
+        break;
+
+    default:
+        qCWarning(Render::Rendering) << "vertexAttribPointer: Unhandled type";
+    }
+}
+
 void GraphicsHelperGL2::blendEquation(GLenum mode)
 {
     m_funcs->glBlendEquation(mode);
@@ -541,6 +562,11 @@ void GraphicsHelperGL2::enablePrimitiveRestart(int)
 {
 }
 
+void GraphicsHelperGL2::enableVertexAttributeArray(int location)
+{
+    m_funcs->glEnableVertexAttribArray(location);
+}
+
 void GraphicsHelperGL2::disablePrimitiveRestart()
 {
 }
diff --git a/src/render/graphicshelpers/graphicshelpergl2_p.h b/src/render/graphicshelpers/graphicshelpergl2_p.h
index a7450430e..7d617937d 100644
--- a/src/render/graphicshelpers/graphicshelpergl2_p.h
+++ b/src/render/graphicshelpers/graphicshelpergl2_p.h
@@ -106,6 +106,7 @@ public:
     void enableClipPlane(int clipPlane) Q_DECL_OVERRIDE;
     void enablei(GLenum cap, GLuint index) Q_DECL_OVERRIDE;
     void enablePrimitiveRestart(int primitiveRestartIndex) Q_DECL_OVERRIDE;
+    void enableVertexAttributeArray(int location) Q_DECL_OVERRIDE;
     void frontFace(GLenum mode) Q_DECL_OVERRIDE;
     QSize getRenderBufferDimensions(GLuint renderBufferId) Q_DECL_OVERRIDE;
     QSize getTextureDimensions(GLuint textureId, GLenum target, uint level = 0) Q_DECL_OVERRIDE;
@@ -127,6 +128,7 @@ public:
     uint uniformByteSize(const ShaderUniform &description) Q_DECL_OVERRIDE;
     void useProgram(GLuint programId) Q_DECL_OVERRIDE;
     void vertexAttribDivisor(GLuint index, GLuint divisor) Q_DECL_OVERRIDE;
+    void vertexAttributePointer(GLenum shaderDataType, GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid *pointer) Q_DECL_OVERRIDE;
 
     void glUniform1fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
     void glUniform2fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
diff --git a/src/render/graphicshelpers/graphicshelpergl3_2.cpp b/src/render/graphicshelpers/graphicshelpergl3_2.cpp
index bb3547dd7..e879e1ce6 100644
--- a/src/render/graphicshelpers/graphicshelpergl3_2.cpp
+++ b/src/render/graphicshelpers/graphicshelpergl3_2.cpp
@@ -279,6 +279,38 @@ void GraphicsHelperGL3_2::vertexAttribDivisor(GLuint index, GLuint divisor)
     qCWarning(Render::Rendering) << "Vertex attribute divisor not available with OpenGL 3.2 core";
 }
 
+void GraphicsHelperGL3_2::vertexAttributePointer(GLenum shaderDataType,
+                                                 GLuint index,
+                                                 GLint size,
+                                                 GLenum type,
+                                                 GLboolean normalized,
+                                                 GLsizei stride,
+                                                 const GLvoid *pointer)
+{
+    switch (shaderDataType) {
+    case GL_FLOAT:
+    case GL_FLOAT_VEC2:
+    case GL_FLOAT_VEC3:
+    case GL_FLOAT_VEC4:
+        m_funcs->glVertexAttribPointer(index, size, type, normalized, stride, pointer);
+        break;
+
+    case GL_INT:
+    case GL_INT_VEC2:
+    case GL_INT_VEC3:
+    case GL_INT_VEC4:
+    case GL_UNSIGNED_INT:
+    case GL_UNSIGNED_INT_VEC2:
+    case GL_UNSIGNED_INT_VEC3:
+    case GL_UNSIGNED_INT_VEC4:
+        m_funcs->glVertexAttribIPointer(index, size, type, stride, pointer);
+        break;
+
+    default:
+        qCWarning(Render::Rendering) << "vertexAttribPointer: Unhandled type";
+    }
+}
+
 void GraphicsHelperGL3_2::blendEquation(GLenum mode)
 {
     m_funcs->glBlendEquation(mode);
@@ -822,6 +854,11 @@ void GraphicsHelperGL3_2::enablePrimitiveRestart(int primitiveRestartIndex)
     m_funcs->glEnable(GL_PRIMITIVE_RESTART);
 }
 
+void GraphicsHelperGL3_2::enableVertexAttributeArray(int location)
+{
+    m_funcs->glEnableVertexAttribArray(location);
+}
+
 void GraphicsHelperGL3_2::disablePrimitiveRestart()
 {
     m_funcs->glDisable(GL_PRIMITIVE_RESTART);
diff --git a/src/render/graphicshelpers/graphicshelpergl3_2_p.h b/src/render/graphicshelpers/graphicshelpergl3_2_p.h
index 5595d1bc3..94ff4b4eb 100644
--- a/src/render/graphicshelpers/graphicshelpergl3_2_p.h
+++ b/src/render/graphicshelpers/graphicshelpergl3_2_p.h
@@ -108,6 +108,7 @@ public:
     void enableClipPlane(int clipPlane) Q_DECL_OVERRIDE;
     void enablei(GLenum cap, GLuint index) Q_DECL_OVERRIDE;
     void enablePrimitiveRestart(int primitiveRestartIndex) Q_DECL_OVERRIDE;
+    void enableVertexAttributeArray(int location) Q_DECL_OVERRIDE;
     void frontFace(GLenum mode) Q_DECL_OVERRIDE;
     QSize getRenderBufferDimensions(GLuint renderBufferId) Q_DECL_OVERRIDE;
     QSize getTextureDimensions(GLuint textureId, GLenum target, uint level = 0) Q_DECL_OVERRIDE;
@@ -129,6 +130,7 @@ public:
     uint uniformByteSize(const ShaderUniform &description) Q_DECL_OVERRIDE;
     void useProgram(GLuint programId) Q_DECL_OVERRIDE;
     void vertexAttribDivisor(GLuint index, GLuint divisor) Q_DECL_OVERRIDE;
+    void vertexAttributePointer(GLenum shaderDataType, GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid *pointer) Q_DECL_OVERRIDE;
 
     void glUniform1fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
     void glUniform2fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
diff --git a/src/render/graphicshelpers/graphicshelpergl3_3.cpp b/src/render/graphicshelpers/graphicshelpergl3_3.cpp
index abde62355..fbb1455c6 100644
--- a/src/render/graphicshelpers/graphicshelpergl3_3.cpp
+++ b/src/render/graphicshelpers/graphicshelpergl3_3.cpp
@@ -276,6 +276,38 @@ void GraphicsHelperGL3_3::vertexAttribDivisor(GLuint index, GLuint divisor)
     m_funcs->glVertexAttribDivisor(index, divisor);
 }
 
+void GraphicsHelperGL3_3::vertexAttributePointer(GLenum shaderDataType,
+                                                 GLuint index,
+                                                 GLint size,
+                                                 GLenum type,
+                                                 GLboolean normalized,
+                                                 GLsizei stride,
+                                                 const GLvoid *pointer)
+{
+    switch (shaderDataType) {
+    case GL_FLOAT:
+    case GL_FLOAT_VEC2:
+    case GL_FLOAT_VEC3:
+    case GL_FLOAT_VEC4:
+        m_funcs->glVertexAttribPointer(index, size, type, normalized, stride, pointer);
+        break;
+
+    case GL_INT:
+    case GL_INT_VEC2:
+    case GL_INT_VEC3:
+    case GL_INT_VEC4:
+    case GL_UNSIGNED_INT:
+    case GL_UNSIGNED_INT_VEC2:
+    case GL_UNSIGNED_INT_VEC3:
+    case GL_UNSIGNED_INT_VEC4:
+        m_funcs->glVertexAttribIPointer(index, size, type, stride, pointer);
+        break;
+
+    default:
+        qCWarning(Render::Rendering) << "vertexAttribPointer: Unhandled type";
+    }
+}
+
 void GraphicsHelperGL3_3::blendEquation(GLenum mode)
 {
     m_funcs->glBlendEquation(mode);
@@ -819,6 +851,11 @@ void GraphicsHelperGL3_3::enablePrimitiveRestart(int primitiveRestartIndex)
     m_funcs->glEnable(GL_PRIMITIVE_RESTART);
 }
 
+void GraphicsHelperGL3_3::enableVertexAttributeArray(int location)
+{
+    m_funcs->glEnableVertexAttribArray(location);
+}
+
 void GraphicsHelperGL3_3::disablePrimitiveRestart()
 {
     m_funcs->glDisable(GL_PRIMITIVE_RESTART);
diff --git a/src/render/graphicshelpers/graphicshelpergl3_3_p.h b/src/render/graphicshelpers/graphicshelpergl3_3_p.h
index 12ef374d3..3b03cf851 100644
--- a/src/render/graphicshelpers/graphicshelpergl3_3_p.h
+++ b/src/render/graphicshelpers/graphicshelpergl3_3_p.h
@@ -108,6 +108,7 @@ public:
     void enableClipPlane(int clipPlane) Q_DECL_OVERRIDE;
     void enablei(GLenum cap, GLuint index) Q_DECL_OVERRIDE;
     void enablePrimitiveRestart(int primitiveRestartIndex) Q_DECL_OVERRIDE;
+    void enableVertexAttributeArray(int location) Q_DECL_OVERRIDE;
     void frontFace(GLenum mode) Q_DECL_OVERRIDE;
     QSize getRenderBufferDimensions(GLuint renderBufferId) Q_DECL_OVERRIDE;
     QSize getTextureDimensions(GLuint textureId, GLenum target, uint level = 0) Q_DECL_OVERRIDE;
@@ -129,6 +130,7 @@ public:
     uint uniformByteSize(const ShaderUniform &description) Q_DECL_OVERRIDE;
     void useProgram(GLuint programId) Q_DECL_OVERRIDE;
     void vertexAttribDivisor(GLuint index, GLuint divisor) Q_DECL_OVERRIDE;
+    void vertexAttributePointer(GLenum shaderDataType, GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid *pointer) Q_DECL_OVERRIDE;
 
     void glUniform1fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
     void glUniform2fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
diff --git a/src/render/graphicshelpers/graphicshelpergl4.cpp b/src/render/graphicshelpers/graphicshelpergl4.cpp
index f428b667c..434ffd783 100644
--- a/src/render/graphicshelpers/graphicshelpergl4.cpp
+++ b/src/render/graphicshelpers/graphicshelpergl4.cpp
@@ -338,6 +338,45 @@ void GraphicsHelperGL4::vertexAttribDivisor(GLuint index, GLuint divisor)
     m_funcs->glVertexAttribDivisor(index, divisor);
 }
 
+void GraphicsHelperGL4::vertexAttributePointer(GLenum shaderDataType,
+                                               GLuint index,
+                                               GLint size,
+                                               GLenum type,
+                                               GLboolean normalized,
+                                               GLsizei stride,
+                                               const GLvoid *pointer)
+{
+    switch (shaderDataType) {
+    case GL_FLOAT:
+    case GL_FLOAT_VEC2:
+    case GL_FLOAT_VEC3:
+    case GL_FLOAT_VEC4:
+        m_funcs->glVertexAttribPointer(index, size, type, normalized, stride, pointer);
+        break;
+
+    case GL_INT:
+    case GL_INT_VEC2:
+    case GL_INT_VEC3:
+    case GL_INT_VEC4:
+    case GL_UNSIGNED_INT:
+    case GL_UNSIGNED_INT_VEC2:
+    case GL_UNSIGNED_INT_VEC3:
+    case GL_UNSIGNED_INT_VEC4:
+        m_funcs->glVertexAttribIPointer(index, size, type, stride, pointer);
+        break;
+
+    case GL_DOUBLE:
+    case GL_DOUBLE_VEC2:
+    case GL_DOUBLE_VEC3:
+    case GL_DOUBLE_VEC4:
+        m_funcs->glVertexAttribLPointer(index, size, type, stride, pointer);
+        break;
+
+    default:
+        qCWarning(Render::Rendering) << "vertexAttribPointer: Unhandled type";
+    }
+}
+
 void GraphicsHelperGL4::glUniform1fv(GLint location, GLsizei count, const GLfloat *values)
 {
     m_funcs->glUniform1fv(location, count, values);
@@ -1071,6 +1110,11 @@ void GraphicsHelperGL4::enablePrimitiveRestart(int primitiveRestartIndex)
     m_funcs->glEnable(GL_PRIMITIVE_RESTART);
 }
 
+void GraphicsHelperGL4::enableVertexAttributeArray(int location)
+{
+    m_funcs->glEnableVertexAttribArray(location);
+}
+
 void GraphicsHelperGL4::disablePrimitiveRestart()
 {
     m_funcs->glDisable(GL_PRIMITIVE_RESTART);
diff --git a/src/render/graphicshelpers/graphicshelpergl4_p.h b/src/render/graphicshelpers/graphicshelpergl4_p.h
index 8bb759b3b..e636832b3 100644
--- a/src/render/graphicshelpers/graphicshelpergl4_p.h
+++ b/src/render/graphicshelpers/graphicshelpergl4_p.h
@@ -106,6 +106,7 @@ public:
     void enableClipPlane(int clipPlane) Q_DECL_OVERRIDE;
     void enablei(GLenum cap, GLuint index) Q_DECL_OVERRIDE;
     void enablePrimitiveRestart(int primitiveRestartIndex) Q_DECL_OVERRIDE;
+    void enableVertexAttributeArray(int location) Q_DECL_OVERRIDE;
     void frontFace(GLenum mode) Q_DECL_OVERRIDE;
     QSize getRenderBufferDimensions(GLuint renderBufferId) Q_DECL_OVERRIDE;
     QSize getTextureDimensions(GLuint textureId, GLenum target, uint level = 0) Q_DECL_OVERRIDE;
@@ -127,6 +128,7 @@ public:
     uint uniformByteSize(const ShaderUniform &description) Q_DECL_OVERRIDE;
     void useProgram(GLuint programId) Q_DECL_OVERRIDE;
     void vertexAttribDivisor(GLuint index, GLuint divisor) Q_DECL_OVERRIDE;
+    void vertexAttributePointer(GLenum shaderDataType, GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid *pointer) Q_DECL_OVERRIDE;
 
     void glUniform1fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
     void glUniform2fv(GLint location, GLsizei count, const GLfloat *value) Q_DECL_OVERRIDE;
diff --git a/src/render/graphicshelpers/graphicshelperinterface_p.h b/src/render/graphicshelpers/graphicshelperinterface_p.h
index 49bec44f1..45326eb91 100644
--- a/src/render/graphicshelpers/graphicshelperinterface_p.h
+++ b/src/render/graphicshelpers/graphicshelperinterface_p.h
@@ -123,6 +123,7 @@ public:
     virtual void    enableClipPlane(int clipPlane) = 0;
     virtual void    enablei(GLenum cap, GLuint index) = 0;
     virtual void    enablePrimitiveRestart(int primitiveRestartIndex) = 0;
+    virtual void    enableVertexAttributeArray(int location) = 0;
     virtual void    frontFace(GLenum mode) = 0;
     virtual QSize   getRenderBufferDimensions(GLuint renderBufferId) = 0;
     virtual QSize   getTextureDimensions(GLuint textureId, GLenum target, uint level = 0) = 0;
@@ -144,6 +145,7 @@ public:
     virtual uint    uniformByteSize(const ShaderUniform &description) = 0;
     virtual void    useProgram(GLuint programId) = 0;
     virtual void    vertexAttribDivisor(GLuint index, GLuint divisor) = 0;
+    virtual void    vertexAttributePointer(GLenum shaderDataType, GLuint index, GLint size, GLenum type, GLboolean normalized, GLsizei stride, const GLvoid *pointer) = 0;
 
     virtual void glUniform1fv(GLint location, GLsizei count, const GLfloat *value) = 0;
     virtual void glUniform2fv(GLint location, GLsizei count, const GLfloat *value) = 0;