MOAITextLabel:getTextBounds it was the execution result, the return value is incorrect.

[makotok]

MOAITextLabel:getTextBounds it was the execution result, the return value is incorrect.

• Test Code

    font = MOAIFont.new()
    font:load( 'arial-rounded.TTF')

    textbox = MOAITextBox.new()
    textbox:setString("Test Text String")
    textbox:setFont(font)
    textbox:setTextSize(7.5, 163)
    textbox:setRect(0, 0, 100, 200)
    textbox:setAlignment(MOAITextBox.LEFT_JUSTIFY)
    textbox:setYFlip(true)

    layer = MOAILayer.new()
    layer:insertProp(textbox)

    xMin, yMin, xMax, yMax = textbox:getStringBounds(1, #textbox:getString())
    print("TestMOAITextBox:test_getStringBounds", xMin, yMin, xMax, yMax)

• V1.5 Console

TestMOAITextBox:test_getStringBounds    0   17  77  57

• develop Console

TestMOAITextBox:test_getStringBounds    -50 -95 27  -52

[Vavius]

Looks like the new implementation returns bounds relative to center of the rect - a bug.

Another issue that I was facing is how the height is calculated. For many use cases (like crossing text) height should be taken as line height instead of each glyph's bounding box.

[patrickmeehan]

Will look into this, guys. Thanks!

[Vavius]

Here is what I use locally (to get constant line height irrespective to the actual rendered glyphs):

for ( u32 i = spanIdx; i < end; ++i ) {
    MOAITextSprite& sprite = this->mSprites [ i ];
    MOAIGlyph& glyph = *sprite.mGlyph;

    if ( glyph.mWidth > 0.0f ) {

        ZLRect glyphRect = glyph.GetRect ( sprite.mPen.mX, sprite.mPen.mY, sprite.mScale.mX, sprite.mScale.mY );

        // Update the glyphRect with glyphset's metrics,
        // Taking into the account line ascent and lineHeight to properly
        // handle descenders and ascenders: p j q g l i
        float fontSize = sprite.mStyle->GetSize ();
        MOAIGlyphSet* glyphSet = sprite.mStyle->GetFont ()->GetGlyphSet ( fontSize );
        float deckHeight = glyphSet->GetHeight () * sprite.mScale.mY;
        float deckAscent = glyphSet->GetAscent () * sprite.mScale.mY;
        glyphRect.mYMax = sprite.mPen.mY - deckAscent;
        glyphRect.mYMin = glyphRect.mYMax - deckHeight;

        if ( result ) {
            rect.Grow ( glyphRect );
        }
        else {
            rect = glyphRect;
            result = true;
        }
    }
}

[patrickmeehan]

I'll need to expose a way to get either. I redid some of that stuff so I could line up billboarded text correctly with the original text in an SVG, but I understand why you'd need the other height.

[patrickmeehan]

OK, re the centered textbox, the behavior did but the value is correct (for the new implementation). getStringBounds/getTextBounds returns the bounds in model space. To make the 'autoflip' textbox behavior easier to implement, I now center the glyphs around the origin.

Would it be worth modifying that method to return the coords in 'text space' vs model space?

[Vavius]

Is 'text space' a top-left origin, y facing down? Then definitely not.

I expect values to be in model space. In Makoto's post he have textbox rect non-centered, with origin in top-left (or bottom-right). But getStringBounds returns bounds as if origin was centered. Maybe we should apply offset before returning bounds? For centered bounds (what I use) the behaviour will be the same.

[makotok]

I was a little more testing.

• Test Code

    self.textbox:setRect(0, 0, 100, 200)
    self.textbox:setAlignment(MOAITextBox.LEFT_JUSTIFY, MOAITextBox.TOP_JUSTIFY)
    xMin, yMin, xMax, yMax = self.textbox:getStringBounds(1, #self.textbox:getString())
    print("TestMOAITextBox:test_getStringBounds_1", xMin, yMin, xMax, yMax)

    self.textbox:setRect(0, 0, 100, 200)
    self.textbox:setAlignment(MOAITextBox.RIGHT_JUSTIFY, MOAITextBox.BOTTOM_JUSTIFY)
    xMin, yMin, xMax, yMax = self.textbox:getStringBounds(1, #self.textbox:getString())
    print("TestMOAITextBox:test_getStringBounds_2", xMin, yMin, xMax, yMax)

    self.textbox:setRect(-50, -50, 50, 150)
    self.textbox:setAlignment(MOAITextBox.LEFT_JUSTIFY, MOAITextBox.TOP_JUSTIFY)
    xMin, yMin, xMax, yMax = self.textbox:getStringBounds(1, #self.textbox:getString())
    print("TestMOAITextBox:test_getStringBounds_3", xMin, yMin, xMax, yMax)

    self.textbox:setRect(-50, -50, 50, 150)
    self.textbox:setAlignment(MOAITextBox.RIGHT_JUSTIFY, MOAITextBox.BOTTOM_JUSTIFY)
    xMin, yMin, xMax, yMax = self.textbox:getStringBounds(1, #self.textbox:getString())
    print("TestMOAITextBox:test_getStringBounds_4", xMin, yMin, xMax, yMax)

• develop branch output

TestMOAITextBox:test_getStringBounds_1  -50 -95 27  -52
TestMOAITextBox:test_getStringBounds_2  -27 65  50  108
TestMOAITextBox:test_getStringBounds_3  -50 -95 27  -52
TestMOAITextBox:test_getStringBounds_4  -27 65  50  108

• V1.5-stable branch output

TestMOAITextBox:test_getStringBounds_1  0   17  77  57
TestMOAITextBox:test_getStringBounds_2  23  17  100 57
TestMOAITextBox:test_getStringBounds_3  -50 -33 27  7
TestMOAITextBox:test_getStringBounds_4  -27 -33 50  7

I think that is better to behave as before desirable. If possible.

I by this problem, some of the components (TextInput) did not work.
Perhaps there is a possibility that the same thing happens even others.

As a workaround, setRect always center is set to 0.
Or, I add the difference between the width deviated from the center.

[makotok]

Thank you everyone.
Anyway, my component was able to cope with this by adding an offset.

As a new external specification, what should be the getTextBounds / getStringBounds function?