Why this simple program don't show white square?

import std.stdio;

import derelict.opengl3.gl;
import derelict.glfw3.glfw3;

const uint width = 200;
const uint height = 200;

void init()
{
	glViewport(0,0,width,height);
	glMatrixMode(GL_PROJECTION);
	glLoadIdentity();
	glOrtho(-width,width,-height,height,-1,1);
	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
}

void display()
{
	glClear(GL_COLOR_BUFFER_BIT);
	glBegin(GL_POLYGON);
		glVertex2d(0,0);
		glVertex2d(0,height);
		glVertex2d(width,height);
		glVertex2d(height,0);
	glEnd();
}

void main()
{
	DerelictGL.load();
	DerelictGLFW3.load();
	glfwInit();
	GLFWwindow window;
	window = glfwCreateWindow(width,height,GLFW_WINDOWED,"Hello DerelictGLFW3",null);
	init();
	bool opened = true;
	while(opened)
	{
		opened = !glfwGetWindowParam(window,GLFW_CLOSE_REQUESTED) && !glfwGetKey(window,GLFW_KEY_ESC);
		display();
		glfwSwapBuffers(window);
		glfwWaitEvents();
	}
	glfwTerminate();
}

On Monday, 3 September 2012 at 15:21:59 UTC, Zhenya wrote:
> Why this simple program don't show white square?
> void display()
> {
> 	glClear(GL_COLOR_BUFFER_BIT);
> 	glBegin(GL_POLYGON);
> 		glVertex2d(0,0);
> 		glVertex2d(0,height);
> 		glVertex2d(width,height);
> 		glVertex2d(height,0);        <<<<<<<< glVertex2d(width, 0)
> 	glEnd();
> }

If that doesn't work, maybe you need to wind the vertices the other way to avoid backface culling, ie:

glVertex2d(0, 0)
glVertex2d(width, 0)
glVertex2d(width, height)
glVertex2d(0, height)

On Monday, 3 September 2012 at 16:57:08 UTC, cal wrote:
> On Monday, 3 September 2012 at 15:21:59 UTC, Zhenya wrote:
>> Why this simple program don't show white square?
>> void display()
>> {
>> 	glClear(GL_COLOR_BUFFER_BIT);
>> 	glBegin(GL_POLYGON);
>> 		glVertex2d(0,0);
>> 		glVertex2d(0,height);
>> 		glVertex2d(width,height);
>> 		glVertex2d(height,0);        <<<<<<<< glVertex2d(width, 0)
>> 	glEnd();
>> }
>
> If that doesn't work, maybe you need to wind the vertices the other way to avoid backface culling, ie:
>
> glVertex2d(0, 0)
> glVertex2d(width, 0)
> glVertex2d(width, height)
> glVertex2d(0, height)

that dosn't work

On Monday, 3 September 2012 at 17:02:46 UTC, Zhenya wrote:
> that dosn't work

How large is your window?

glViewport(0,0,width,height);

should really be setting to the window size - so if you make your window 800,800, this should be

glViewport(0,0,800,800);

On Monday, 3 September 2012 at 17:08:55 UTC, cal wrote:
> On Monday, 3 September 2012 at 17:02:46 UTC, Zhenya wrote:
>> that dosn't work
>
> How large is your window?
>
> glViewport(0,0,width,height);
>
> should really be setting to the window size - so if you make your window 800,800, this should be
>
> glViewport(0,0,800,800);

Just saw it, never mind. Also, I think before you draw, you need to set the matrix mode to modelview, and load identity...

glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
display();

On Monday, 3 September 2012 at 17:12:04 UTC, cal wrote:
> On Monday, 3 September 2012 at 17:08:55 UTC, cal wrote:
>> On Monday, 3 September 2012 at 17:02:46 UTC, Zhenya wrote:
>>> that dosn't work
>>
>> How large is your window?
>>
>> glViewport(0,0,width,height);
>>
>> should really be setting to the window size - so if you make your window 800,800, this should be
>>
>> glViewport(0,0,800,800);
>
> Just saw it, never mind. Also, I think before you draw, you need to set the matrix mode to modelview, and load identity...
>
> glMatrixMode(GL_MODELVIEW);
> glLoadIdentity();
> display();

const uint width = 200;
const uint height = 200;

> glMatrixMode(GL_MODELVIEW);
> glLoadIdentity();
> display();

I added it to this code,but nothing changed(

On Monday, 3 September 2012 at 17:16:54 UTC, Zhenya wrote:
> I added it to this code,but nothing changed(

Its a puzzler then, FWIW the following code works for me (I don't use GLFW, I have my own window routines, but the opengl-specific calls are the same).

Window("window1", WindowState(0,0,200,200), Flag!"Create".yes, Flag!"Show".yes);
Window.makeCurrent("window1");

glViewport(0,0,200,200);
glClearColor(0,0,0,1);

bool finish = false;
while (!finish)
{
        glMatrixMode(GL_PROJECTION);
        glLoadIdentity();
        glOrtho(-200, 200, -200, 200, -1, 1);
        glClear( GL_COLOR_BUFFER_BIT );
        glBegin(GL_POLYGON);
            glVertex2d(0, 0);
            glVertex2d(0, 200);
            glVertex2d(200, 200);
            glVertex2d(200, 0);
        glEnd();
        Window().swapBuffers();

        if (Window().keyState().keys[KEY.KC_ESCAPE])
            finish = true;
}

Perhaps something in the GLFW init is modyfying some OpenGL defaults or something, you might like to ask on their forum.

On Monday, 3 September 2012 at 15:21:59 UTC, Zhenya wrote:
> Why this simple program don't show white square?
>
> import std.stdio;
>
> import derelict.opengl3.gl;
> import derelict.glfw3.glfw3;
>
> const uint width = 200;
> const uint height = 200;
>
> void init()
> {
> 	glViewport(0,0,width,height);
> 	glMatrixMode(GL_PROJECTION);
> 	glLoadIdentity();
> 	glOrtho(-width,width,-height,height,-1,1);
> 	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
> }
>
> void display()
> {
> 	glClear(GL_COLOR_BUFFER_BIT);
> 	glBegin(GL_POLYGON);
> 		glVertex2d(0,0);
> 		glVertex2d(0,height);
> 		glVertex2d(width,height);
> 		glVertex2d(height,0);
> 	glEnd();
> }
>
> void main()
> {
> 	DerelictGL.load();
> 	DerelictGLFW3.load();
> 	glfwInit();
> 	GLFWwindow window;
> 	window = glfwCreateWindow(width,height,GLFW_WINDOWED,"Hello DerelictGLFW3",null);
> 	init();
> 	bool opened = true;
> 	while(opened)
> 	{
> 		opened = !glfwGetWindowParam(window,GLFW_CLOSE_REQUESTED) && !glfwGetKey(window,GLFW_KEY_ESC);
> 		display();
> 		glfwSwapBuffers(window);
> 		glfwWaitEvents();
> 	}
> 	glfwTerminate();
> }

width and height must be int, not uint.
After window = glfwCreateWindow();
put glfwMakeContextCurrent(window);
And it will work!

On Monday, 3 September 2012 at 18:47:25 UTC, Ivan Agafonov wrote:
> On Monday, 3 September 2012 at 15:21:59 UTC, Zhenya wrote:
>> Why this simple program don't show white square?
>>
>> import std.stdio;
>>
>> import derelict.opengl3.gl;
>> import derelict.glfw3.glfw3;
>>
>> const uint width = 200;
>> const uint height = 200;
>>
>> void init()
>> {
>> 	glViewport(0,0,width,height);
>> 	glMatrixMode(GL_PROJECTION);
>> 	glLoadIdentity();
>> 	glOrtho(-width,width,-height,height,-1,1);
>> 	glClearColor(0.0f, 0.0f, 0.0f, 0.0f);
>> }
>>
>> void display()
>> {
>> 	glClear(GL_COLOR_BUFFER_BIT);
>> 	glBegin(GL_POLYGON);
>> 		glVertex2d(0,0);
>> 		glVertex2d(0,height);
>> 		glVertex2d(width,height);
>> 		glVertex2d(height,0);
>> 	glEnd();
>> }
>>
>> void main()
>> {
>> 	DerelictGL.load();
>> 	DerelictGLFW3.load();
>> 	glfwInit();
>> 	GLFWwindow window;
>> 	window = glfwCreateWindow(width,height,GLFW_WINDOWED,"Hello DerelictGLFW3",null);
>> 	init();
>> 	bool opened = true;
>> 	while(opened)
>> 	{
>> 		opened = !glfwGetWindowParam(window,GLFW_CLOSE_REQUESTED) && !glfwGetKey(window,GLFW_KEY_ESC);
>> 		display();
>> 		glfwSwapBuffers(window);
>> 		glfwWaitEvents();
>> 	}
>> 	glfwTerminate();
>> }
>
> width and height must be int, not uint.
> After window = glfwCreateWindow();
> put glfwMakeContextCurrent(window);
> And it will work!
Thank you very much)

But why it doesn't convert uint to int correctly?