I tried using a core OpenGL context on my old MacBook (2010) and got a crash
from glGetString from the Pascal bindings (a legacy 2.x context doesn’t crash).
I pulled out the related functions from glext.pp where it crashes in
Load_GL_ARB_blend_func_extended from Load_GL_VERSION_3_3. It looks like the
function pointer for glGetString wasn’t loaded but how could that be? I’m using
SDL to load the context and I need to use glGetString in order to even return
what the highest OpenGL version is on the system.
* thread #1: tid = 0x750fc, 0x00007fff9362ffc8 libGL.dylib`glGetString + 15,
queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1,
address=0x0)
frame #0: 0x00007fff9362ffc8 libGL.dylib`glGetString + 15
libGL.dylib`glGetString + 15:
-> 0x7fff9362ffc8: movq (%rcx), %rdi
0x7fff9362ffcb: movq 0x3b0(%rcx), %rcx
0x7fff9362ffd2: movl %eax, %esi
0x7fff9362ffd4: popq %rbp
(lldb) bt
* thread #1: tid = 0x750fc, 0x00007fff9362ffc8 libGL.dylib`glGetString + 15,
queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1,
address=0x0)
* frame #0: 0x00007fff9362ffc8 libGL.dylib`glGetString + 15
frame #1: 0x00000001000a78fc
OpenGL-Tests`GLEXT_$$_LOAD_GL_ARB_BLEND_FUNC_EXTENDED$BOOLEAN$$BOOLEAN + 76
frame #2: 0x000000010004b6b1
OpenGL-Tests`TEST_1_VERTATTRIBS_$$_TESTVERTATTRIBS + 201
frame #3: 0x0000000100000ae5 OpenGL-Tests`PASCALMAIN + 69
frame #4: 0x00000001000205d4 OpenGL-Tests`FPC_SysEntry + 12
frame #5: 0x0000000100000a4e OpenGL-Tests`FPC_SYSTEMMAIN + 54
frame #6: 0x00000001000009f4 OpenGL-Tests`start + 52
(lldb)
procedure Load_GL_VERSION_3_3x(var allOK: boolean; out isVersion: Boolean);
var
dummy: boolean;
begin
isVersion := Load_GL_ARB_blend_func_extended(true);
if not isVersion then allOK := false;
if not Load_GL_ARB_sampler_objects(true) then allOK := false;
if not Load_GL_ARB_timer_query(true) then allOK := false;
if not Load_GL_ARB_vertex_type_2_10_10_10_rev(true) then allOK := false;
Load_GL_VERSION_3_2x(allOK, dummy);
end;
function Load_GL_ARB_blend_func_extended(LoadAsCore: boolean): Boolean;
var
extstring: String;
begin
Result := False;
extstring := String(PChar(glGetString(GL_EXTENSIONS)));
if LoadAsCore or glext_ExtensionSupported('GL_ARB_blend_func_extended',
extstring) then
begin
glBindFragDataLocationIndexed :=
wglGetProcAddress('glBindFragDataLocationIndexed');
if not Assigned(glBindFragDataLocationIndexed) then Exit;
glGetFragDataIndex := wglGetProcAddress('glGetFragDataIndex');
if not Assigned(glGetFragDataIndex) then Exit;
Result := True;
end;
end;
Regards,
Ryan Joseph
_______________________________________________
fpc-pascal maillist - fpc-pascal@lists.freepascal.org
http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
