woolfik

09-03-2015, 04:58 AM

Hello there

I have array of points that I draw in OpenGL (code below):

procedure Draw();

begin

glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);

glClearColor(255,255,255,0);

glLoadIdentity; //biezaca macierz = I

gluLookAt(0,0,KameraZ, 0,0,0,0,1,0);

glRotatef(Theta, 1.0, 0.0, 0.0);

glRotatef(Phi, 0.0, 1.0, 0.0);

glTranslated(MoveX,MoveY,0);

glPointSize(2);

glBegin(GL_POINTS);

for I := 0 to High(Stars) - 1 do //stars is my array of array of points

for j := 0 to High(stars[i]) - 1 do

begin

glColor3ub(stars[i,j].R,stars[i,j].g, stars[i,j].b);

glVertex3i(stars[i,j].x,stars[i,j].y, stars[i,j].distance);

end;

glEnd;

SwapBuffers(wglGetCurrentDC);

end;

In my application onMouseMove event set KameraZ (zoom), Theta & Phi (rotate angle) and MoveX, MoveY (move left/right & up/down).

Now ... when user hold shift and click on scene I like to find point under clicked coords (mouse coords converted to opengl coords). After find first one (in this coords can be lot of points but I need only one neares camera look) i like to compare and find this point in my array by X, Y and Distans. I have to do that because point in array (stars) has more informations (OpenGL only show location of this point). I try to do that with such code:

procedure MouseClick(const X, Y: Integer);

type

T3D_Point = array [1..3] of Double;

var

i, j: Integer;

pt: T3D_Point;

function GetOGLPos(X, Y: Integer): T3D_Point;

var

viewport: array [1..4] of Integer;

modelview: array [1..16] of Double;

projection: array [1..16] of Double;

winZ: Single;

begin

glGetDoublev( GL_MODELVIEW_MATRIX, modelview );

glGetDoublev( GL_PROJECTION_MATRIX, projection );

glGetIntegerv( GL_VIEWPORT, viewport );

if( Y = 0 )then Y := 1;

glReadPixels(X, -Y, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, winZ );

gluUnProject(X, viewport[4]-Y, winZ,

modelview, projection, viewport,

Result[1], Result[2], Result[3]);

end;

begin

pt := GetOGLPos(X,Y);

for I := 0 to High(stars) do

for j := 0 to High(stars[i]) do

if (CompareValue(stars[i,j].x, pt[1], 2) = EqualsValue) and

(CompareValue(stars[i,j].y, pt[2], 2) = EqualsValue) then

begin

sbar.Panels[0].Text := 'Line:'+IntToStr(i)+',Point:'+IntToStr(j)+

',R:'+FloatToStr(Round(stars[i,j].R))+

',G:'+FloatToStr(Round(stars[i,j].G))+

',B:'+FloatToStr(Round(stars[i,j].B));

Break;

end;

end;

procedure pPaintMouseDown(Sender: TObject;

Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

begin

if (ssShift in Shift) and (Button = mbLeft) then

MouseClick(x,y);

end;

but even if KameraZ = 100 and Theta, Phi, MoveX and MoveY is set to 0 sbar.Panels[0].Text is empty. Why?

I have array of points that I draw in OpenGL (code below):

procedure Draw();

begin

glClear(GL_COLOR_BUFFER_BIT or GL_DEPTH_BUFFER_BIT);

glClearColor(255,255,255,0);

glLoadIdentity; //biezaca macierz = I

gluLookAt(0,0,KameraZ, 0,0,0,0,1,0);

glRotatef(Theta, 1.0, 0.0, 0.0);

glRotatef(Phi, 0.0, 1.0, 0.0);

glTranslated(MoveX,MoveY,0);

glPointSize(2);

glBegin(GL_POINTS);

for I := 0 to High(Stars) - 1 do //stars is my array of array of points

for j := 0 to High(stars[i]) - 1 do

begin

glColor3ub(stars[i,j].R,stars[i,j].g, stars[i,j].b);

glVertex3i(stars[i,j].x,stars[i,j].y, stars[i,j].distance);

end;

glEnd;

SwapBuffers(wglGetCurrentDC);

end;

In my application onMouseMove event set KameraZ (zoom), Theta & Phi (rotate angle) and MoveX, MoveY (move left/right & up/down).

Now ... when user hold shift and click on scene I like to find point under clicked coords (mouse coords converted to opengl coords). After find first one (in this coords can be lot of points but I need only one neares camera look) i like to compare and find this point in my array by X, Y and Distans. I have to do that because point in array (stars) has more informations (OpenGL only show location of this point). I try to do that with such code:

procedure MouseClick(const X, Y: Integer);

type

T3D_Point = array [1..3] of Double;

var

i, j: Integer;

pt: T3D_Point;

function GetOGLPos(X, Y: Integer): T3D_Point;

var

viewport: array [1..4] of Integer;

modelview: array [1..16] of Double;

projection: array [1..16] of Double;

winZ: Single;

begin

glGetDoublev( GL_MODELVIEW_MATRIX, modelview );

glGetDoublev( GL_PROJECTION_MATRIX, projection );

glGetIntegerv( GL_VIEWPORT, viewport );

if( Y = 0 )then Y := 1;

glReadPixels(X, -Y, 1, 1, GL_DEPTH_COMPONENT, GL_FLOAT, winZ );

gluUnProject(X, viewport[4]-Y, winZ,

modelview, projection, viewport,

Result[1], Result[2], Result[3]);

end;

begin

pt := GetOGLPos(X,Y);

for I := 0 to High(stars) do

for j := 0 to High(stars[i]) do

if (CompareValue(stars[i,j].x, pt[1], 2) = EqualsValue) and

(CompareValue(stars[i,j].y, pt[2], 2) = EqualsValue) then

begin

sbar.Panels[0].Text := 'Line:'+IntToStr(i)+',Point:'+IntToStr(j)+

',R:'+FloatToStr(Round(stars[i,j].R))+

',G:'+FloatToStr(Round(stars[i,j].G))+

',B:'+FloatToStr(Round(stars[i,j].B));

Break;

end;

end;

procedure pPaintMouseDown(Sender: TObject;

Button: TMouseButton; Shift: TShiftState; X, Y: Integer);

begin

if (ssShift in Shift) and (Button = mbLeft) then

MouseClick(x,y);

end;

but even if KameraZ = 100 and Theta, Phi, MoveX and MoveY is set to 0 sbar.Panels[0].Text is empty. Why?