Drawing A Solid/FIlled Rectangle « cocos2d for iPhone

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Drawing A Solid/FIlled Rectangle

(7 posts) (6 voices)

Started 1 year ago by Petey_Pii
Latest reply from Voles

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Petey_Pii
Member
I'm having trouble finding a way to draw a solid or filled polygon in cocos2d. This is what i have so far:

(init method)
```
vertices[0] = ccp(768, 1);
vertices[1] = ccp(768, 767);
vertices[2] = ccp(1023, 767);
vertices[3] = ccp(1023, 1);
```
(draw method)
```
glColor4ub(255, 255, 255, 255);
ccDrawPoly(vertices, 4, YES);
```
and this draws an outline of a rectangle as expected. so is there an easy way to draw a solid rectangle? my guess would be to use some kind of triangle fan method of drawing polygons but i have no idea where i could find such a method. any help i appreciated
Posted 1 year ago #
mobilebros
Moderator

in ccDrawPoly it calls glDrawArrays, if you want a solid polygon then the first parameter should be GL_TRIANGLE_FAN instead of GL_LINE_(LOOP/STRIP).

Posted 1 year ago #
Petey_Pii
Member

ah, that works great! thank you very much!

Posted 1 year ago #

bradparks
Member

Here's a routine I got from these forums somewhere (I think @Lam did it for the Curves demo he did)

void ccFillPoly( CGPoint *poli, int points, BOOL closePolygon )
  {
    // Default GL states: GL_TEXTURE_2D, GL_VERTEX_ARRAY, GL_COLOR_ARRAY, GL_TEXTURE_COORD_ARRAY
    // Needed states: GL_VERTEX_ARRAY,
    // Unneeded states: GL_TEXTURE_2D, GL_TEXTURE_COORD_ARRAY, GL_COLOR_ARRAY
    glDisable(GL_TEXTURE_2D);
    glDisableClientState(GL_TEXTURE_COORD_ARRAY);
    glDisableClientState(GL_COLOR_ARRAY);

    glVertexPointer(2, GL_FLOAT, 0, poli);
    if( closePolygon )
      glDrawArrays(GL_TRIANGLE_FAN, 0, points);
    else
      glDrawArrays(GL_LINE_STRIP, 0, points);

    // restore default state
    glEnableClientState(GL_COLOR_ARRAY);
    glEnableClientState(GL_TEXTURE_COORD_ARRAY);
    glEnable(GL_TEXTURE_2D);
  }

Posted 1 year ago #

idsky
Member

A solid rectangle function which just takes 2 points (opposite corners) would be nice. I just made this version which seems to work. If anyone knows if there is a more efficient / better way, speak up.

You might like to have 'ccDrawRect' and have a 3rd BOOL parameter for filled or not, but this is all I wanted.

void ccDrawFilledRect( CGPoint v1, CGPoint v2 )
{
	CGPoint poli[]={v1,CGPointMake(v1.x,v2.y),v2,CGPointMake(v2.x,v1.y)};

	// Default GL states: GL_TEXTURE_2D, GL_VERTEX_ARRAY, GL_COLOR_ARRAY, GL_TEXTURE_COORD_ARRAY
	// Needed states: GL_VERTEX_ARRAY,
	// Unneeded states: GL_TEXTURE_2D, GL_TEXTURE_COORD_ARRAY, GL_COLOR_ARRAY
	glDisable(GL_TEXTURE_2D);
	glDisableClientState(GL_TEXTURE_COORD_ARRAY);
	glDisableClientState(GL_COLOR_ARRAY);

	glVertexPointer(2, GL_FLOAT, 0, poli);
	glDrawArrays(GL_TRIANGLE_FAN, 0, 4);

	// restore default state
	glEnableClientState(GL_COLOR_ARRAY);
	glEnableClientState(GL_TEXTURE_COORD_ARRAY);
	glEnable(GL_TEXTURE_2D);
}

Posted 1 year ago #

crmagicxxx
Member

You have convenient cocos2d macros CC_ENABLE_DEFAULT_GL_STATES() and CC_DISABLE_DEFAULT_GL_STATES() just to simplify look of your method...

Posted 1 year ago #
Voles
Member

Sorry for the bump, but just want to say thanks to @bradparks and @Lam for the ccFillPoly-function. Have been searching for this since hours... Thanks a lot!

PS a thanks-button would be a handy feature for this forum, no?

Posted 1 week ago #

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