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PiouPiou

OpenGL Open a 3.2 OPENGL context or superior

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PiouPiou    105
[b]Hi all,[/b]

just 2 questions
here is my code, I use the correct method to open [b]a context "core profile"?[/b]
I have a yellow texture, please consider I clearly see my yellow triangle when I'm context <3.2 and if I open a context> = 3.2 my texture disappears (the triangle become black)

thank you in advance for your answers

my code :
[CODE]
#define WIDTH 800
#define HEIGHT 600
#define NBP 32
#define MAJOR 3 // for creating context opengl MAJOR VERSION TRY MAJOR = 3
#define MINOR 1 // for creating context opengl MINOR VERSION TRY MINOR >= 2
#define FULLSCREEN false
#define PI 3.14159265
#define TEXTURESIZE 256 * 256 * 3
#include <Windows.h>
#include <math.h>
#include <stdio.h> // fopen, fread, fclose
#include "GL3\gl3.h"

class mat4
{
public:
float m[16];
const float* GetMatriceOpengl() const;
void mat4::Identity();
};
#ifdef __cplusplus
extern "C" {
#endif
GLAPI void APIENTRY glClearColor (GLfloat red, GLfloat green, GLfloat blue, GLfloat alpha);
GLAPI void APIENTRY glClear (GLbitfield mask);
GLAPI const GLubyte * APIENTRY glGetString (GLenum name);
GLAPI void APIENTRY glEnable (GLenum cap);
GLAPI void APIENTRY glDrawArrays (GLenum mode, GLint first, GLsizei count);
GLAPI void APIENTRY glDrawElements (GLenum mode, GLsizei count, GLenum type, const GLvoid *indices);
GLAPI void APIENTRY glDisable (GLenum cap);
GLAPI void APIENTRY glViewport (GLint x, GLint y, GLsizei width, GLsizei height);
GLAPI void APIENTRY glBindTexture (GLenum target, GLuint texture);
GLAPI void APIENTRY glGenTextures (GLsizei n, GLuint *textures);
GLAPI void APIENTRY glTexImage2D (GLenum target, GLint level, GLint internalformat, GLsizei width, GLsizei height, GLint border, GLenum format, GLenum type, const GLvoid *pixels);
GLAPI void APIENTRY glTexParameteri (GLenum target, GLenum pname, GLint param);
GLAPI void APIENTRY glGetIntegerv (GLenum pname, GLint *params);
#ifdef __cplusplus
}
#endif
PFNGLCREATEPROGRAMPROC glCreateProgram = NULL;
PFNGLUNIFORMMATRIX4FVPROC glUniformMatrix4fv = NULL;
PFNGLGENVERTEXARRAYSPROC glGenVertexArrays = NULL;
PFNGLBINDVERTEXARRAYPROC glBindVertexArray = NULL;
PFNGLGENBUFFERSPROC glGenBuffers = NULL;
PFNGLBINDBUFFERPROC glBindBuffer = NULL;
PFNGLBUFFERDATAPROC glBufferData = NULL;
PFNGLVERTEXATTRIBPOINTERPROC glVertexAttribPointer = NULL;
PFNGLENABLEVERTEXATTRIBARRAYPROC glEnableVertexAttribArray = NULL;
PFNGLCREATESHADERPROC glCreateShader = NULL;
PFNGLSHADERSOURCEPROC glShaderSource = NULL;
PFNGLCOMPILESHADERPROC glCompileShader = NULL;
PFNGLBINDATTRIBLOCATIONPROC glBindAttribLocation = NULL;
PFNGLATTACHSHADERPROC glAttachShader = NULL;
PFNGLLINKPROGRAMPROC glLinkProgram = NULL;
PFNGLUSEPROGRAMPROC glUseProgram = NULL;
PFNGLGETUNIFORMLOCATIONPROC glGetUniformLocation = NULL;
PFNGLGETSHADERIVPROC glGetShaderiv = NULL;
PFNGLGETPROGRAMIVPROC glGetProgramiv = NULL;
PFNGLGETSHADERINFOLOGPROC glGetShaderInfoLog = NULL;
PFNGLGETPROGRAMINFOLOGPROC glGetProgramInfoLog = NULL;
PFNGLACTIVETEXTUREPROC glActiveTexture = NULL;
PFNGLUNIFORM1IPROC glUniform1i = NULL;
PFNGLGETSTRINGIPROC glGetStringi = NULL;
unsigned int vao;
unsigned int vbo[2];
float incx, incy, incz;
GLuint vshader;
GLuint fshader;
GLuint program;
char source1[1024*1024*4];
char source2[1024*1024*4];
short taillex, tailley;
unsigned char *data = new unsigned char[TEXTURESIZE];
GLuint texture;
GLuint tex;
mat4 pmatrix;
mat4 mmatrix;
float A, B, C, D, E, F, AD, BD;
LRESULT CALLBACK WndProc( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam );
float triangle[] = { // pos // Map
-1.0f, 1.0f, 1.0f, 0.0f, 0.0f,
-1.0f, -1.0f, 1.0f, 0.0f, 4.0f,
1.0f, -1.0f, 1.0f, 4.0f, 4.0f };
GLuint indicetriangle[] = { 0,1,2 };
#define WGL_CONTEXT_MAJOR_VERSION_ARB 0x2091
#define WGL_CONTEXT_MINOR_VERSION_ARB 0x2092
#define WGL_CONTEXT_PROFILE_MASK_ARB 0x9126
#define WGL_CONTEXT_CORE_PROFILE_BIT_ARB 0x00000001
int attriblist[] = { WGL_CONTEXT_MAJOR_VERSION_ARB, MAJOR, WGL_CONTEXT_MINOR_VERSION_ARB, MINOR, WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB, 0, 0 };
HGLRC wglCreateContextAttribsARB(HDC hDC, HGLRC hShareContext, const int *attribList)
{
typedef HGLRC (APIENTRY * PFNWGLCREATECONTEXTATTRIBSARBPROC)(HDC hDC, HGLRC hShareContext, const int *attribList);
static PFNWGLCREATECONTEXTATTRIBSARBPROC pfnCreateContextAttribsARB = 0;

HGLRC hContext = 0;
HGLRC hCurrentContext = wglGetCurrentContext();

if (!hCurrentContext)
{
if (!(hCurrentContext = wglCreateContext(hDC)))
return 0;
if (!wglMakeCurrent(hDC, hCurrentContext))
{
wglDeleteContext(hCurrentContext);
return 0;
}
pfnCreateContextAttribsARB = reinterpret_cast<PFNWGLCREATECONTEXTATTRIBSARBPROC>(wglGetProcAddress("wglCreateContextAttribsARB"));

if (pfnCreateContextAttribsARB)
hContext = pfnCreateContextAttribsARB(hDC, hShareContext, attribList);
wglMakeCurrent(hDC, 0);
wglDeleteContext(hCurrentContext);
}
else
{
if (!wglMakeCurrent(hDC, hCurrentContext))
return 0;
pfnCreateContextAttribsARB = reinterpret_cast<PFNWGLCREATECONTEXTATTRIBSARBPROC>(wglGetProcAddress("wglCreateContextAttribsARB"));
if (pfnCreateContextAttribsARB)
hContext = pfnCreateContextAttribsARB(hDC, hShareContext, attribList);
}
return hContext;
}
const float* mat4::GetMatriceOpengl() const
{
return &m[0];
}
void mat4::Identity()
{
memset(m, 0, sizeof(float)*16);
m[0] = m[5] = m[10] = m[15] = 1.0f;
}
mat4 MultMatrice(mat4* m, mat4 *n)
{
static mat4 mat;
mat.m[0] = m->m[0]*n->m[0] + m->m[4]*n->m[1] + m->m[8]*n->m[2] + m->m[12]*n->m[3];
mat.m[1] = m->m[1]*n->m[0] + m->m[5]*n->m[1] + m->m[9]*n->m[2] + m->m[13]*n->m[3];
mat.m[2] = m->m[2]*n->m[0] + m->m[6]*n->m[1] + m->m[10]*n->m[2] + m->m[14]*n->m[3];
mat.m[3] = m->m[3]*n->m[0] + m->m[7]*n->m[1] + m->m[11]*n->m[2] + m->m[15]*n->m[3];
mat.m[4] = m->m[0]*n->m[4] + m->m[4]*n->m[5] + m->m[8]*n->m[6] + m->m[12]*n->m[7];
mat.m[5] = m->m[1]*n->m[4] + m->m[5]*n->m[5] + m->m[9]*n->m[6] + m->m[13]*n->m[7];
mat.m[6] = m->m[2]*n->m[4] + m->m[6]*n->m[5] + m->m[10]*n->m[6] + m->m[14]*n->m[7];
mat.m[7] = m->m[3]*n->m[4] + m->m[7]*n->m[5] + m->m[11]*n->m[6] + m->m[15]*n->m[7];
mat.m[8] = m->m[0]*n->m[8] + m->m[4]*n->m[9] + m->m[8]*n->m[10] + m->m[12]*n->m[11];
mat.m[9] = m->m[1]*n->m[8] + m->m[5]*n->m[9] + m->m[9]*n->m[10] + m->m[13]*n->m[11];
mat.m[10] = m->m[2]*n->m[8] + m->m[6]*n->m[9] + m->m[10]*n->m[10] + m->m[14]*n->m[11];
mat.m[11] = m->m[3]*n->m[8] + m->m[7]*n->m[9] + m->m[11]*n->m[10] + m->m[15]*n->m[11];
mat.m[12] = m->m[0]*n->m[12] + m->m[4]*n->m[13] + m->m[8]*n->m[14] + m->m[12]*n->m[15];
mat.m[13] = m->m[1]*n->m[12] + m->m[5]*n->m[13] + m->m[9]*n->m[14] + m->m[13]*n->m[15];
mat.m[14] = m->m[2]*n->m[12] + m->m[6]*n->m[13] + m->m[10]*n->m[14] + m->m[14]*n->m[15];
mat.m[15] = m->m[3]*n->m[12] + m->m[7]*n->m[13] + m->m[11]*n->m[14] + m->m[15]*n->m[15];

return mat;
}
void glTranslate(mat4 *mat, float x, float y, float z)
{
static mat4 m;
m.m[0] = m.m[5] = m.m[10] = m.m[15] = 1.0f;
m.m[1] = m.m[2] = m.m[3] = m.m[4] = m.m[6] = m.m[7] = m.m[8] = m.m[9] = m.m[11] = 0.0f;
m.m[12] = x;
m.m[13] = y;
m.m[14] = z;
*mat = MultMatrice(mat,&m);
}
void glPerspective( mat4 &mat, float fovy, float ratio, float znear, float zfar )
{
static float ymax, xmax;
static float temp, temp4;
ymax = float(znear * tanf(float(fovy * PI / 360.0f)));
xmax = ymax * ratio;
temp = znear + znear;
temp4 = zfar - znear;
mat.m[0] = znear / xmax;
mat.m[1] =mat.m[2] =mat.m[3] =mat.m[4] =mat.m[6] =mat.m[7] =mat.m[8] =mat.m[9] =mat.m[12] =mat.m[13] =mat.m[15] = 0.0;
mat.m[5] = znear / ymax;
mat.m[10] = (-zfar - znear) / temp4;
mat.m[11] = -1.0;
mat.m[14] = (-temp * zfar) / temp4;
}
void LoadFile(char *name, char *buffer)
{
FILE *hfile = fopen(name, "rb");
if (hfile)
{
fread(buffer, 1, 10000, hfile);
fclose(hfile);
}
}
void Init()
{
glCreateProgram = (PFNGLCREATEPROGRAMPROC)wglGetProcAddress("glCreateProgram");
glUniformMatrix4fv = (PFNGLUNIFORMMATRIX4FVPROC)wglGetProcAddress("glUniformMatrix4fv");
glGenVertexArrays = (PFNGLGENVERTEXARRAYSPROC)wglGetProcAddress("glGenVertexArrays");
glBindVertexArray = (PFNGLBINDVERTEXARRAYPROC)wglGetProcAddress("glBindVertexArray");
glGenBuffers = (PFNGLGENBUFFERSPROC)wglGetProcAddress("glGenBuffers");
glBindBuffer = (PFNGLBINDBUFFERPROC)wglGetProcAddress("glBindBuffer");
glBufferData = (PFNGLBUFFERDATAPROC)wglGetProcAddress("glBufferData");
glVertexAttribPointer = (PFNGLVERTEXATTRIBPOINTERPROC)wglGetProcAddress("glVertexAttribPointer");
glEnableVertexAttribArray = (PFNGLENABLEVERTEXATTRIBARRAYPROC)wglGetProcAddress("glEnableVertexAttribArray");
glCreateShader = (PFNGLCREATESHADERPROC)wglGetProcAddress("glCreateShader");
glShaderSource = (PFNGLSHADERSOURCEPROC)wglGetProcAddress("glShaderSource");
glCompileShader = (PFNGLCOMPILESHADERPROC)wglGetProcAddress("glCompileShader");
glBindAttribLocation = (PFNGLBINDATTRIBLOCATIONPROC)wglGetProcAddress("glBindAttribLocation");
glAttachShader = (PFNGLATTACHSHADERPROC)wglGetProcAddress("glAttachShader");
glLinkProgram = (PFNGLLINKPROGRAMPROC)wglGetProcAddress("glLinkProgram");
glUseProgram = (PFNGLUSEPROGRAMPROC)wglGetProcAddress("glUseProgram");
glGetUniformLocation = (PFNGLGETUNIFORMLOCATIONPROC)wglGetProcAddress("glGetUniformLocation");
glGetShaderiv = (PFNGLGETSHADERIVPROC)wglGetProcAddress("glGetShaderiv");
glGetProgramiv = (PFNGLGETPROGRAMIVPROC)wglGetProcAddress("glGetProgramiv");
glGetShaderInfoLog = (PFNGLGETSHADERINFOLOGPROC)wglGetProcAddress("glGetShaderInfoLog");
glGetProgramInfoLog = (PFNGLGETPROGRAMINFOLOGPROC)wglGetProcAddress("glGetProgramInfoLog");
glActiveTexture = (PFNGLACTIVETEXTUREPROC)wglGetProcAddress("glActiveTexture");
glUniform1i = (PFNGLUNIFORM1IPROC)wglGetProcAddress("glUniform1i");
glGetStringi = (PFNGLGETSTRINGIPROC)wglGetProcAddress("glGetStringi");
glGenVertexArrays(1, &vao);
glBindVertexArray(vao);
glGenBuffers(2, &vbo[0]);
glBindBuffer(GL_ARRAY_BUFFER, vbo[0]);
glBufferData(GL_ARRAY_BUFFER, sizeof(triangle), triangle, GL_STATIC_DRAW);
glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, vbo[1]);
glBufferData(GL_ELEMENT_ARRAY_BUFFER, sizeof(indicetriangle), indicetriangle, GL_STATIC_DRAW);
glVertexAttribPointer((GLuint)0, 3, GL_FLOAT, GL_FALSE, 20, 0);
glVertexAttribPointer((GLuint)1, 2, GL_FLOAT, GL_FALSE, 20, (void*)12);
glEnableVertexAttribArray(0);
glEnableVertexAttribArray(1);
glBindVertexArray(0);
const char *src = source1;
vshader = glCreateShader(GL_VERTEX_SHADER);
fshader = glCreateShader(GL_FRAGMENT_SHADER);
LoadFile("vert.txt", source1);
glShaderSource(vshader, 1, &src, NULL);
glCompileShader(vshader);
LoadFile("frag.txt", source2);
src = source2;
glShaderSource(fshader, 1, &src, NULL);
glCompileShader(fshader);
program = glCreateProgram();
glAttachShader(program, vshader);
glAttachShader(program, fshader);
// glBindAttribLocation(program,0, "vert");
// glBindAttribLocation(program,1, "texture");
glLinkProgram(program);
tex = glGetUniformLocation(program, "gsample");

taillex = 256;
tailley = 256;

unsigned char *p = data;
for (int t = 0 ; t < taillex*tailley ; t++) // i create a yellow texture just for testing
*p++ = 255, *p++ = 255, *p++ = 0;
glGenTextures(1, &texture);
glBindTexture(GL_TEXTURE_2D, texture);
glTexImage2D(GL_TEXTURE_2D , 0 , 3 , taillex , tailley , 0 , GL_RGB , GL_UNSIGNED_BYTE , data);
glTexParameteri(GL_TEXTURE_2D , GL_TEXTURE_MIN_FILTER , GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D , GL_TEXTURE_MAG_FILTER , GL_LINEAR);
glTexParameteri(GL_TEXTURE_2D , GL_TEXTURE_WRAP_S , GL_REPEAT);
glTexParameteri(GL_TEXTURE_2D , GL_TEXTURE_WRAP_T , GL_REPEAT);
glBindTexture(GL_TEXTURE_2D, 0);
};
int MainSub()
{
glUseProgram(program);
glEnable(GL_CULL_FACE);
glEnable(GL_DEPTH_TEST);
glClearColor(0.0f,0.2f,0.4f,1.0f);
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
mmatrix.Identity();
incz = -3.5f;
glTranslate(&mmatrix, incx, incy, incz);
glUniformMatrix4fv(glGetUniformLocation(program, "projectionmatrix"), 1, GL_FALSE, pmatrix.GetMatriceOpengl());
glUniformMatrix4fv(glGetUniformLocation(program, "modelmatrix"), 1, GL_FALSE, mmatrix.GetMatriceOpengl());
glBindVertexArray(vao);
glUniform1i(tex, 0);
glActiveTexture(GL_TEXTURE0);
glBindTexture(GL_TEXTURE_2D,texture);
//glDrawArrays(GL_TRIANGLES, 0, 3); // draw first object
glDrawElements(GL_TRIANGLES, 3, GL_UNSIGNED_INT,0);
glBindVertexArray(0);
glUseProgram(0);
return true;
}
int WINAPI WinMain(HINSTANCE hinst,HINSTANCE hprev, LPSTR cmdline, int cmdshow)
{
static MSG msg;
HWND hwnd;
HDC hdc;
HGLRC hrc;
WNDCLASSEX wnd;
DWORD style;
DWORD exstyle;

wnd.cbSize = sizeof( WNDCLASSEX ) ;
wnd.style = CS_HREDRAW | CS_VREDRAW | CS_OWNDC;
wnd.lpfnWndProc = WndProc;
wnd.hInstance = hinst;
wnd.hCursor = LoadCursor( NULL, IDC_HAND );
wnd.hIcon = LoadIcon(NULL, IDI_ASTERISK);
wnd.hIconSm = LoadIcon(NULL, IDI_WINLOGO);
wnd.hbrBackground = 0;
wnd.lpszMenuName = 0;
wnd.cbClsExtra = 0;
wnd.cbWndExtra = 0;
wnd.lpszClassName = "wc";
RegisterClassEx(&wnd);

if (FULLSCREEN)
{
DEVMODE dm;
memset(&dm, 0, sizeof(dm));
dm.dmSize = sizeof(dm);
dm.dmPelsWidth = WIDTH;
dm.dmPelsHeight = HEIGHT;
dm.dmBitsPerPel = NBP;
dm.dmFields = DM_BITSPERPEL | DM_PELSWIDTH | DM_PELSHEIGHT;
ChangeDisplaySettings(&dm, CDS_FULLSCREEN);
style = WS_POPUP;
exstyle = WS_EX_APPWINDOW;
ShowCursor(FALSE);
}
else
{
style = WS_OVERLAPPEDWINDOW;
exstyle = WS_EX_APPWINDOW | WS_EX_WINDOWEDGE;
}
RECT rc = { 0, 0, WIDTH, HEIGHT };
AdjustWindowRectEx( &rc, style, false, exstyle );
hwnd = CreateWindowEx( exstyle, "wc", "MyWindows", style, 0, 0, rc.right - rc.left, rc.bottom - rc.top, NULL, NULL, hinst, NULL );
static PIXELFORMATDESCRIPTOR pfd =
{
sizeof(PIXELFORMATDESCRIPTOR),
1,
PFD_DRAW_TO_WINDOW | PFD_SUPPORT_OPENGL | PFD_DOUBLEBUFFER,
PFD_TYPE_RGBA,
NBP,
0, 0, 0, 0, 0, 0,
0,
0,
0,
0, 0, 0, 0,
16, // 16Bit Z-Buffer (Depth Buffer)
0,
0,
PFD_MAIN_PLANE,
0,
0, 0, 0
};
hdc = GetDC(hwnd);
unsigned int pixelformat = ChoosePixelFormat(hdc, &pfd);
SetPixelFormat(hdc, pixelformat, &pfd);
if (MAJOR < 3) // open Standard Context
hrc = wglCreateContext(hdc);
else
hrc = wglCreateContextAttribsARB(hdc, 0, attriblist); // open à New Core Context
wglMakeCurrent(hdc, hrc);
ShowWindow( hwnd, cmdshow );

Init();
const GLubyte *version = glGetString(GL_VERSION);
MessageBox(NULL,(char *)version ,"Opengl Version",MB_OK|MB_ICONEXCLAMATION);
while( msg.message != WM_QUIT )
{
if( PeekMessage( &msg, 0, 0, 0, PM_REMOVE ) )
{
TranslateMessage( &msg );
DispatchMessage( &msg );
}
MainSub();
SwapBuffers(hdc); // Double Buffer
}

if (FULLSCREEN)
{
ChangeDisplaySettings(NULL,0);
ShowCursor(TRUE);
}
wglMakeCurrent(NULL,NULL);
wglDeleteContext(hrc);
hrc = 0;
ReleaseDC(hwnd,hdc);
hdc = 0;
DestroyWindow(hwnd);
hwnd = 0;
UnregisterClass("wclasse",hinst);
delete [] data;
return static_cast<int>( msg.wParam );
}
LRESULT CALLBACK WndProc( HWND hwnd, UINT message, WPARAM wparam, LPARAM lparam )
{
static short width;
static short height;
switch( message )
{

case WM_DESTROY:
PostQuitMessage( 0 );
break;
case WM_SIZE:
width= LOWORD(lparam);
height = HIWORD(lparam);
if ( height == 0 )
height = 1;
glViewport(0, 0, width, height);
glPerspective( pmatrix, 45.0f, (GLfloat)width/(GLfloat)height, 0.1f, 100.0f );
break;
default:
return DefWindowProc( hwnd, message, wparam, lparam );
}
return 0;
}
[/CODE]

Vertex shader :
[CODE]
#version 330
layout(location = 0)in vec3 vertex;
layout(location = 1)in vec2 texture;
out vec2 _texture;
uniform mat4 projectionmatrix;
uniform mat4 modelmatrix;
void main(void)
{
mat4 mvpMatrix = projectionmatrix * modelmatrix;
_texture = texture;
gl_Position = mvpMatrix * vec4(vertex, 1.0);
}
[/CODE]

Fragment Shader :
[CODE]
#version 330
in vec2 _texture;
out vec4 fragcolor;
uniform sampler2D gsample;
void main(void)
{
fragcolor = texture2D(gsample, _texture);
}
[/CODE]

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clb    2147
#1 guideline: In debug mode, after each call to a glXXX function, call http://www.opengl.org/sdk/docs/man/xhtml/glGetError.xml . With OpenGL, you can never be sure, and you must at least detect the few problems OpenGL is capable of reporting. I call the following function after each glXXX call:
[code]

int Graphics::CheckErrors(const char *hintOperation)
{
#ifndef OPTIMIZED_RELEASE
GLenum returnError = 0;
GLenum error = GL_NO_ERROR+1;
int maxIters = 100; // Arbitrarily cap the number of iterations to avoid infinite loop on buggy drivers.
while(error != GL_NO_ERROR && maxIters-- > 0)
{
error = glGetError();
if (error != GL_NO_ERROR)
{
LOGW("glGetError: \"%s\" failed: Error %s (0x%X) received!\n", hintOperation, GetGLErrorString(error), (int)error);
returnError = error;
}
}
return returnError;
#else
return 0;
#endif
}
[/code]
Then I do something along the lines of
[code]
#define GL_CALL(x) { x; Graphics::CheckErrors(#x); }

GL_CALL(glBindVertexArray(vb->vertexArrayObject));
[/code]

#2: Use [url="http://www.gremedy.com/"]gDEBugger[/url] to peek inside your application execution. This allows you to verify GL server side state and confirm that everything is as you expected.

I find that the combination of #1 and #2 has allowed me to get past all the problems I've encountered, without having to spend days scratching my head.

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PiouPiou    105
thanks Clb,

I delete all the verification that the source is as short as possible.

but it's true that I should use glGetError but even with use are
this does not solve my problem :-(

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clb    2147
With all the glGetError checks in place, does any of them report any errors? What did gDEBugger say?

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PiouPiou    105
I'm an idiot

in fact I did not put [b]glGetError everywhere[/b], I thought one was enough to know if opengl met an error.
[b]I was in my wrong :-([/b]
my problem of texture came from :

glTexImage2D (GL_TEXTURE_2D, 0, [b]3[/b], taillex, tailley, 0, GL_RGB, GL_UNSIGNED_BYTE, data);

glGetError tells me an "GL_INVALID_ENUM"

must be replaced by:

glTexImage2D (GL_TEXTURE_2D, 0, [b]GL_RGB[/b], taillex, tailley, 0, GL_RGB, GL_UNSIGNED_BYTE, data);


I have not had time yet to test gldebugger (but I'll do it soon)

thank you very much Clb for helping me find this bug.

another question:

attriblist int [] = {WGL_CONTEXT_MAJOR_VERSION_ARB, MAJOR, WGL_CONTEXT_MINOR_VERSION_ARB, MINOR, [b]WGL_CONTEXT_PROFILE_MASK_ARB, WGL_CONTEXT_CORE_PROFILE_BIT_ARB, 0, 0[/b]};

and

attriblist int [] = {WGL_CONTEXT_MAJOR_VERSION_ARB, MAJOR, WGL_CONTEXT_MINOR_VERSION_ARB, MINOR, [b]0[/b]};

appears to be identical?

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      There are studios selling applications which is just copying any 3Dgraphic content and regenerating into another new window. especially for CAVE Virtual reality experience. so that the user opens REvite or CAD or any other 3D applications and opens a model. then when the user selects the rendered window the VR application copies the 3D model information from the OpenGL window. 
      I got the clue that the VR application replaces the windows opengl32.dll file. how this is possible ... how can we copy the 3d content from the current OpenGL window.
      anyone, please help me .. how to go further... to create an application like VR CAVE. 
       
      Thanks
    • By cebugdev
      hi all,

      i am trying to build an OpenGL 2D GUI system, (yeah yeah, i know i should not be re inventing the wheel, but this is for educational and some other purpose only),
      i have built GUI system before using 2D systems such as that of HTML/JS canvas, but in 2D system, i can directly match a mouse coordinates to the actual graphic coordinates with additional computation for screen size/ratio/scale ofcourse.
      now i want to port it to OpenGL, i know that to render a 2D object in OpenGL we specify coordiantes in Clip space or use the orthographic projection, now heres what i need help about.
      1. what is the right way of rendering the GUI? is it thru drawing in clip space or switching to ortho projection?
      2. from screen coordinates (top left is 0,0 nd bottom right is width height), how can i map the mouse coordinates to OpenGL 2D so that mouse events such as button click works? In consideration ofcourse to the current screen/size dimension.
      3. when let say if the screen size/dimension is different, how to handle this? in my previous javascript 2D engine using canvas, i just have my working coordinates and then just perform the bitblk or copying my working canvas to screen canvas and scale the mouse coordinates from there, in OpenGL how to work on a multiple screen sizes (more like an OpenGL ES question).
      lastly, if you guys know any books, resources, links or tutorials that handle or discuss this, i found one with marekknows opengl game engine website but its not free,
      Just let me know. Did not have any luck finding resource in google for writing our own OpenGL GUI framework.
      IF there are no any available online, just let me know, what things do i need to look into for OpenGL and i will study them one by one to make it work.
      thank you, and looking forward to positive replies.
    • By fllwr0491
      I have a few beginner questions about tesselation that I really have no clue.
      The opengl wiki doesn't seem to talk anything about the details.
       
      What is the relationship between TCS layout out and TES layout in?
      How does the tesselator know how control points are organized?
          e.g. If TES input requests triangles, but TCS can output N vertices.
             What happens in this case?
      In this article,
      http://www.informit.com/articles/article.aspx?p=2120983
      the isoline example TCS out=4, but TES in=isoline.
      And gl_TessCoord is only a single one.
      So which ones are the control points?
      How are tesselator building primitives?
    • By Orella
      I've been developing a 2D Engine using SFML + ImGui.
      Here you can see an image
      The editor is rendered using ImGui and the scene window is a sf::RenderTexture where I draw the GameObjects and then is converted to ImGui::Image to render it in the editor.
      Now I need to create a 3D Engine during this year in my Bachelor Degree but using SDL2 + ImGui and I want to recreate what I did with the 2D Engine. 
      I've managed to render the editor like I did in the 2D Engine using this example that comes with ImGui. 
      3D Editor preview
      But I don't know how to create an equivalent of sf::RenderTexture in SDL2, so I can draw the 3D scene there and convert it to ImGui::Image to show it in the editor.
      If you can provide code will be better. And if you want me to provide any specific code tell me.
      Thanks!
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