Global.b glextimp_errors
Global.s glextimp_error_string

CompilerSelect #PB_Compiler_OS

   CompilerCase #PB_OS_Windows ;{ Windows
      Macro glextimp_Prototype : Prototype : EndMacro
      Macro glextimp_GetProcAddress(Prototype, function, function_name)
         Global.Prototype function = wglGetProcAddress_(function_name)
         If Not function
            Define.s glextimp_error = "glextimp_GetProcAddress : error " + function_name + " does not exist" : Debug glextimp_error
            glextimp_error_string + glextimp_error + #CRLF$
            glextimp_errors + 1
         EndIf
      EndMacro

      #WGL_CONTEXT_FORWARD_COMPATIBLE_BIT_ARB = $00000002
      #WGL_CONTEXT_MAJOR_VERSION_ARB          = $2091
      #WGL_CONTEXT_MINOR_VERSION_ARB          = $2092
      #WGL_CONTEXT_FLAGS_ARB                  = $2094

      ; No more needed (seen in PB 5.44)
      ;Import "opengl32.lib"
      ;;from luis reply http://purebasic.fr/english/viewtopic.php?f=13&t=45687&start=15#p446875
      ;CompilerIf (#PB_Compiler_Processor = #PB_Processor_x86)
      ;   wglGetProcAddress_(s.p-ascii) As "_wglGetProcAddress@4"
      ;CompilerElse   
      ;   wglGetProcAddress_(s.p-ascii) As "wglGetProcAddress"
      ;CompilerEndIf
      ;EndImport
      
      Prototype PFNwglCreateContextAttribsPROC (hDC.i, hShareContext.i, *attribList)
      ;Global.PFNwglCreateContextAttribsPROC wglCreateContextAttribsARB = wglGetProcAddress_("wglCreateContextAttribsARB")
      ;}

   CompilerCase #PB_OS_MacOS ;{ MacOS
      Macro glextimp_Prototype : PrototypeC : EndMacro
      Macro glextimp_GetProcAddress(Prototype, function, function_name)
         Global.Prototype function = GetFunction(glextimp_hOpenGLlib, function_name)
         If Not function
            Define.s glextimp_error = "glextimp_GetProcAddress : error " + function_name + " does not exist" : Debug glextimp_error
            glextimp_error_string + glextimp_error + #CRLF$
            glextimp_errors + 1
         EndIf
      EndMacro
      ;ImportC "/System/Library/Frameworks/OpenGL.framework/OpenGL"
      ;Global.i glextimp_hOpenGLlib = OpenLibrary(#PB_Any, "/System/Library/Frameworks/OpenGL.framework/OpenGL")
      ;}
      
   CompilerCase #PB_OS_Linux ;{ Linux
      ;ImportC "/usr/lib/libX11.a"+Chr('"')+" -l"+Chr('"')+"GL"
      ImportC "/usr/lib/x86_64-linux-gnu/libX11.a"+Chr('"')+" -l"+Chr('"')+"GL"
      EndImport
      ImportC "/usr/lib/libGLU.a"
      EndImport
      ;ImportC "/usr/lib/libX11.a"
      ImportC "/usr/lib/x86_64-linux-gnu/libX11.a"
      EndImport
      ;ImportC "/usr/lib/libX11.a"+Chr('"')+" -l"+Chr('"')+"GL"
      ImportC "/usr/lib/x86_64-linux-gnu/libX11.a"+Chr('"')+" -l"+Chr('"')+"GL"
      EndImport
      ImportC "GL"
      ;}
      
CompilerEndSelect

; CompilerIf #PB_Compiler_OS <> #PB_OS_MacOS
; 
; glGenBuffers(n.i, *buffers)
; glBindBuffer(target.i, buffer.i)
; glBufferData(target.i, size.i, *data, usage.i)
; glBufferSubData(target.i, offset.i, size.i, *data)
; glMapBuffer(target.i, access.i)
; glUnmapBuffer(target.i)
; glEnableVertexAttribArray(index.i)
; glVertexAttribPointer(index.i, size.i, type.i, normalized.b, stride.i, *pointer)
; glCreateShader(type.i)
; glShaderSource(shader.i, count.i, *stringBuffer, *length)
; glCompileShader(shader.i)
; glCreateProgram()
; glAttachShader(program.i, shader.i)
; glGetShaderInfoLog(shader.i, maxLength.i, *length.integer, *infoLog.ascii)
; glLinkProgram(program.i)
; glUseProgram(program.i)
; glGetUniformLocation(program.i, name.p-ascii)
; glUniformMatrix4fv(location.i, count.i, transpose.b, *value)
;
; ; OpenGL 3.3 : Not supported on WindowsXP and MacOS Snow Leopard
; glGenVertexArrays(n.i, *ids.integer)
; glBindVertexArray(id.i)
; glDeleteVertexArrays(n.i, *buffers)
; 
; EndImport
; 
; CompilerElse

;{ Prototypes
glextimp_Prototype PFNGLGENBUFFERSPROC (n.l, *buffers)
glextimp_Prototype PFNGLBINDBUFFERPROC (target.l, buffer.l)
glextimp_Prototype PFNGLBUFFERDATAPROC (target.l, size.i, *data, usage.l)
glextimp_Prototype PFNGLBUFFERSUBDATAPROC (target.l, offset.i, size.i, *data)
glextimp_Prototype PFNGLMAPBUFFERPROC (target.l, Access.l)
glextimp_Prototype PFNGLUNMAPBUFFERPROC (target.l)
glextimp_Prototype PFNGLDELETEBUFFERSPROC (n.l, *buffers)

glextimp_Prototype PFNGLENABLEVERTEXATTRIBARRAYPROC (index.l)
glextimp_Prototype PFNGLVERTEXATTRIBPOINTERPROC (index.l, size.l, type.l, normalized.b, stride.l, *pointer)
;glextimp_Prototype PFNGLVERTEXATTRIBI1IPROC (index.l, v.l)
;glextimp_Prototype PFNGLVERTEXATTRIB1FPROC (index.l, v0.f)
glextimp_Prototype PFNGLVERTEXATTRIB4FVPROC (index.l, *v.Float)
glextimp_Prototype PFNGLVERTEXATTRIB4FPROC (index.l, v0.f, v1.f, v2.f, v3.f)
glextimp_Prototype PFNGLVERTEXATTRIB3FVPROC (index.l, *v.Float)
glextimp_Prototype PFNGLVERTEXATTRIB3FPROC (index.l, v0.f, v1.f, v2.f)

glextimp_Prototype PFNGLCREATESHADERPROC (type.l)
glextimp_Prototype PFNGLSHADERSOURCEPROC (shader.l, count.l, *string, *length)
glextimp_Prototype PFNGLCOMPILESHADERPROC (shader.l)
glextimp_Prototype PFNGLATTACHSHADERPROC (program.l, shader.l)
glextimp_Prototype PFNGLDETACHSHADERPROC (program.l, shader.l)
glextimp_Prototype PFNGLDELETESHADERPROC (shader.l)
glextimp_Prototype PFNGLGETSHADERIVPROC (shader.l, pname.l, *params)
glextimp_Prototype PFNGLGETSHADERINFOLOGPROC (shader.l, maxLength.l, *length, *infoLog)
glextimp_Prototype PFNGLLINKPROGRAMPROC (program.l)
glextimp_Prototype PFNGLCREATEPROGRAMPROC ()
glextimp_Prototype PFNGLUSEPROGRAMPROC (program.l)
glextimp_Prototype PFNGLGETPROGRAMIVPROC (program.l, pname.l, *params)
glextimp_Prototype PFNGLDELETEPROGRAMPROC (program.l)

glextimp_Prototype PFNGLBINDATTRIBLOCATIONPROC (program.l, index.l, *name) ;.p-ascii) ; Plante en 64 bits !
glextimp_Prototype PFNGLDISABLEVERTEXATTRIBARRAYPROC (index.l)
glextimp_Prototype PFNGLGETUNIFORMLOCATIONPROC (program.l, name.p-ascii)
glextimp_Prototype PFNGLUNIFORM1IPROC (location.l, v0.l)
glextimp_Prototype PFNGLUNIFORM1FPROC (location.l, v0.f)
glextimp_Prototype PFNGLUNIFORM3FPROC (location.l, v0.f, v1.f, v2.f)
glextimp_Prototype PFNGLUNIFORMMATRIX4FVPROC (location.l, count.l, transpose.b, *value)
glextimp_Prototype PFNGLACTIVETEXTUREPROC (Texture.l)

; OpenGL 3.3 : Not supported on WindowsXP and MacOS Snow Leopard
glextimp_Prototype PFNGLGENVERTEXARRAYSPROC (n.l, *arrays)
glextimp_Prototype PFNGLBINDVERTEXARRAYPROC (Array.l)
glextimp_Prototype PFNGLDELETEVERTEXARRAYSPROC (n.l, *arrays)

glextimp_Prototype PFNGLGENRENDERBUFFERSPROC (n.l, *renderbuffers)
glextimp_Prototype PFNGLBINDRENDERBUFFERPROC (target.l, renderbuffer.l)
glextimp_Prototype PFNGLRENDERBUFFERSTORAGEPROC (target.l, internalformat.l, width.l, height.l)
glextimp_Prototype PFNGLDELETERENDERBUFFERSPROC (n.l, *renderbuffers)

glextimp_Prototype PFNGLGENFRAMEBUFFERSPROC (n.l, *ids)
glextimp_Prototype PFNGLBINDFRAMEBUFFERPROC (target.l, framebuffer.l)
glextimp_Prototype PFNGLFRAMEBUFFERTEXTURE2DPROC (target.l, attachment.l, textarget.l, texture.l, level.l)
glextimp_Prototype PFNGLFRAMEBUFFERRENDERBUFFERPROC (target.l, attachment.l, renderbuffertarget.l, renderbuffer.l)
glextimp_Prototype PFNGLCHECKFRAMEBUFFERSTATUSPROC (target.l)
glextimp_Prototype PFNGLDELETEFRAMEBUFFERSPROC (n.l, *framebuffers)

;}

Procedure.b glextimp_Init()
   CompilerSelect #PB_Compiler_OS

      CompilerCase #PB_OS_Windows ;{ Windows
         ;}

      CompilerCase #PB_OS_MacOS ;{ MacOS
         Global.i glextimp_hOpenGLlib = OpenLibrary(#PB_Any, "/System/Library/Frameworks/OpenGL.framework/OpenGL")
         If Not glextimp_hOpenGLlib : ProcedureReturn #False : EndIf
         ;}

      CompilerCase #PB_OS_Linux ;{ Linux
         ;}

   CompilerEndSelect

   glextimp_GetProcAddress(PFNGLGENBUFFERSPROC, glGenBuffers, "glGenBuffers")
   glextimp_GetProcAddress(PFNGLBINDBUFFERPROC, glBindBuffer, "glBindBuffer")
   glextimp_GetProcAddress(PFNGLBUFFERDATAPROC, glBufferData, "glBufferData")
   glextimp_GetProcAddress(PFNGLBUFFERSUBDATAPROC, glBufferSubData, "glBufferSubData")
   glextimp_GetProcAddress(PFNGLMAPBUFFERPROC, glMapBuffer, "glMapBuffer")
   glextimp_GetProcAddress(PFNGLUNMAPBUFFERPROC, glUnmapBuffer, "glUnmapBuffer")
   glextimp_GetProcAddress(PFNGLDELETEBUFFERSPROC, glDeleteBuffers, "glDeleteBuffers")
   
   glextimp_GetProcAddress(PFNGLENABLEVERTEXATTRIBARRAYPROC, glEnableVertexAttribArray, "glEnableVertexAttribArray")
   glextimp_GetProcAddress(PFNGLVERTEXATTRIBPOINTERPROC, glVertexAttribPointer, "glVertexAttribPointer")
;   glextimp_GetProcAddress(PFNGLVERTEXATTRIBI1IPROC, glVertexAttribI1i, "glVertexAttribI1i")
;   glextimp_GetProcAddress(PFNGLVERTEXATTRIB1FPROC, glVertexAttrib1f, "glVertexAttrib1f")
   glextimp_GetProcAddress(PFNGLVERTEXATTRIB4FVPROC, glVertexAttrib4fv, "glVertexAttrib4fv")
   glextimp_GetProcAddress(PFNGLVERTEXATTRIB4FPROC, glVertexAttrib4f, "glVertexAttrib4f")
   glextimp_GetProcAddress(PFNGLVERTEXATTRIB3FVPROC, glVertexAttrib3fv, "glVertexAttrib3fv")
   glextimp_GetProcAddress(PFNGLVERTEXATTRIB3FPROC, glVertexAttrib3f, "glVertexAttrib3f")
   
   glextimp_GetProcAddress(PFNGLCREATESHADERPROC, glCreateShader, "glCreateShader")
   glextimp_GetProcAddress(PFNGLSHADERSOURCEPROC, glShaderSource, "glShaderSource")
   glextimp_GetProcAddress(PFNGLCOMPILESHADERPROC, glCompileShader, "glCompileShader")
   glextimp_GetProcAddress(PFNGLATTACHSHADERPROC, glAttachShader, "glAttachShader")
   glextimp_GetProcAddress(PFNGLDETACHSHADERPROC, glDetachShader, "glDetachShader")
   glextimp_GetProcAddress(PFNGLDELETESHADERPROC, glDeleteShader, "glDeleteShader")
   glextimp_GetProcAddress(PFNGLGETSHADERIVPROC, glGetShaderiv, "glGetShaderiv")
   glextimp_GetProcAddress(PFNGLGETSHADERINFOLOGPROC, glGetShaderInfoLog, "glGetShaderInfoLog")
   glextimp_GetProcAddress(PFNGLLINKPROGRAMPROC, glLinkProgram, "glLinkProgram")
   glextimp_GetProcAddress(PFNGLCREATEPROGRAMPROC, glCreateProgram, "glCreateProgram")
   glextimp_GetProcAddress(PFNGLUSEPROGRAMPROC, glUseProgram, "glUseProgram")
   glextimp_GetProcAddress(PFNGLGETPROGRAMIVPROC, glGetProgramiv, "glGetProgramiv")
   glextimp_GetProcAddress(PFNGLDELETEPROGRAMPROC, glDeleteProgram, "glDeleteProgram")
   
   glextimp_GetProcAddress(PFNGLBINDATTRIBLOCATIONPROC, glBindAttribLocation, "glBindAttribLocation")
   glextimp_GetProcAddress(PFNGLDISABLEVERTEXATTRIBARRAYPROC, glDisableVertexAttribArray, "glDisableVertexAttribArray")
   glextimp_GetProcAddress(PFNGLGETUNIFORMLOCATIONPROC, glGetUniformLocation, "glGetUniformLocation")
   glextimp_GetProcAddress(PFNGLUNIFORM1IPROC, glUniform1i, "glUniform1i")
   glextimp_GetProcAddress(PFNGLUNIFORM1FPROC, glUniform1f, "glUniform1f")
   glextimp_GetProcAddress(PFNGLUNIFORM3FPROC, glUniform3f, "glUniform3f")
   glextimp_GetProcAddress(PFNGLUNIFORMMATRIX4FVPROC, glUniformMatrix4fv, "glUniformMatrix4fv")
   glextimp_GetProcAddress(PFNGLACTIVETEXTUREPROC, glActiveTexture, "glActiveTexture")

   ; OpenGL 3.3 : Not supported in WindowsXP and MacOS Snow Leopard
   glextimp_GetProcAddress(PFNGLGENVERTEXARRAYSPROC, glGenVertexArrays, "glGenVertexArrays")
   glextimp_GetProcAddress(PFNGLBINDVERTEXARRAYPROC, glBindVertexArray, "glBindVertexArray")
   glextimp_GetProcAddress(PFNGLDELETEVERTEXARRAYSPROC, glDeleteVertexArrays, "glDeleteVertexArrays")
   
   glextimp_GetProcAddress(PFNGLGENRENDERBUFFERSPROC, glGenRenderbuffers, "glGenRenderbuffers")
   glextimp_GetProcAddress(PFNGLBINDRENDERBUFFERPROC, glBindRenderbuffer, "glBindRenderbuffer")
   glextimp_GetProcAddress(PFNGLRENDERBUFFERSTORAGEPROC, glRenderbufferStorage, "glRenderbufferStorage")
   glextimp_GetProcAddress(PFNGLDELETERENDERBUFFERSPROC, glDeleteRenderbuffers, "glDeleteRenderbuffers")
   
   glextimp_GetProcAddress(PFNGLGENFRAMEBUFFERSPROC, glGenFramebuffers, "glGenFramebuffers")
   glextimp_GetProcAddress(PFNGLBINDFRAMEBUFFERPROC, glBindFramebuffer, "glBindFramebuffer")
   glextimp_GetProcAddress(PFNGLFRAMEBUFFERTEXTURE2DPROC, glFramebufferTexture2D, "glFramebufferTexture2D")
   glextimp_GetProcAddress(PFNGLFRAMEBUFFERRENDERBUFFERPROC, glFramebufferRenderbuffer, "glFramebufferRenderbuffer")
   glextimp_GetProcAddress(PFNGLCHECKFRAMEBUFFERSTATUSPROC, glCheckFramebufferStatus, "glCheckFramebufferStatus")
   glextimp_GetProcAddress(PFNGLDELETEFRAMEBUFFERSPROC, glDeleteFramebuffers, "glDeleteFramebuffers")

   If Not glextimp_errors : ProcedureReturn #True : EndIf
EndProcedure

Procedure.b glextimp_Close()
   CompilerSelect #PB_Compiler_OS

      CompilerCase #PB_OS_Windows ;{ Windows
         ;}

      CompilerCase #PB_OS_MacOS ;{ MacOS
         If glextimp_hOpenGLlib
            CloseLibrary(glextimp_hOpenGLlib)
            glextimp_hOpenGLlib = 0
         EndIf
         ;}

      CompilerCase #PB_OS_Linux ;{ Linux
         ;}

   CompilerEndSelect
EndProcedure

; Init OpenGL context to allow wglGetProcAddress_() function to work and to return a not null address
CompilerIf #PB_Compiler_IsMainFile ;{
   OpenWindow(0, 0, 0, 0, 0, "")
   OpenGLGadget(0, 0, 0, 0, 0)
   glextimp_init()
   glextimp_close()
CompilerEndIf ;}

; IDE Options = PureBasic 5.62 (Windows - x86)
; Folding = SAg