CODEWITHSUNDEEP
objective-ccocos2d-iphonefill
Andy M
Andy M

Reputation: 6065

Drawing a filled square with Objective-C / Cocos2D

I'm desperatly trying to draw a filled square with Cocos2D and I can't manage to find an example on how to do it :

Here is my draw method. I succeeded in drawing a square but I can't manage to fill it !

I've read that I need to use a OpenGL method called glDrawArrays with a parameter GL_TRIANGLE_FAN in order to draw a filled square and that's what I tried.

-(void) draw
{
    // Disable textures - we want to draw with plaine colors
    ccGLEnableVertexAttribs( kCCVertexAttribFlag_Position | kCCVertexAttribFlag_Color );

    float l_fRedComponent = 0;
    float l_fGreenComponent = 0;
    float l_fBlueComponent = 0;
    float l_fAlphaComponent = 0;
    [mpColor getRed:&l_fRedComponent green:&l_fGreenComponent blue:&l_fBlueComponent alpha:&l_fAlphaComponent];

    ccDrawColor4F(l_fRedComponent, l_fGreenComponent, l_fBlueComponent, l_fAlphaComponent);
    glLineWidth(10);

    CGPoint l_bottomLeft, l_bottomRight, l_topLeft, l_topRight;
    l_bottomLeft.x = miPosX - miWidth / 2.0f;
    l_bottomLeft.y = miPosY - miHeight /  2.0f;
    l_bottomRight.x = miPosX + miWidth /  2.0f;
    l_bottomRight.y = miPosY - miHeight /  2.0f;
    l_topRight.x = miPosX + miWidth /  2.0f;
    l_topRight.y = miPosY + miHeight /  2.0f;
    l_topLeft.x = miPosX - miWidth /  2.0f;
    l_topLeft.y = miPosY + miHeight /  2.0f;

    CGPoint vertices[] = { l_bottomLeft, l_bottomRight, l_topRight, l_topLeft, l_bottomLeft };
    int l_arraySize = sizeof(vertices) / sizeof(CGPoint) ;

    // My old way of doing this, it draws a square, but not filled.
    //ccDrawPoly( vertices, l_arraySize, NO);

    // Deprecated method :(
    //glVertexPointer(2, GL_FLOAT, 0, vertices);

    // I've found something related to this method to replace the deprecated one, but can't understand this method !
    glVertexAttribPointer(kCCVertexAttrib_Position, 3, GL_FLOAT, GL_FALSE, 0, vertices);
    glDrawArrays(GL_TRIANGLE_FAN, 0, l_arraySize);  
}

I've found some examples with the old version of Cocos2D (1.0) but since it's been upgraded to version 2.0 "lately" all the examples I find give me compilation errors !

Could anyone enlight my path here please ?

Upvotes: 1

Views: 3396

Answers (2)

CodeSmile
CodeSmile

Reputation: 64477

I didn't know today is "Reinvent the Wheel" day. :)

ccDrawSolidRect(CGPoint origin, CGPoint destination, ccColor4F color);

If you were to go all crazy and wanted to draw filled polygons, there's also:

ccDrawSolidPoly(const CGPoint *poli, NSUInteger numberOfPoints, ccColor4F color);

The "solid" methods are new in Cocos2D 2.x.

Upvotes: 7

Morion
Morion

Reputation: 10860

You can simply create CCLayerColor instance with needed content size and use it as filled square. In other case you have to triangulate your polygon (it will have two triangles in case of square) and draw it using OpenGL.

---EDIT Didn't test this code, find it with google, but it seems to work fine.

http://www.deluge.co/?q=cocos-2d-custom-filled-polygon

Upvotes: 0

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