Question

I want to display PDF file in iPad using CATiled Layer
All is well but when i use CATiledLayer in my app and run it , PDF file will display like this shown in image

Here is my Code

For CATiled layer

   tiledLayer = [CATiledLayer layer];
     tiledLayer.delegate = self;
     //Set load block of tiled layer
     tiledLayer.tileSize = CGSizeMake(1024.0, 1024.0);
     tiledLayer.levelsOfDetail = 1000; 
     tiledLayer.levelsOfDetailBias = 1000;

For drawInContext

 CGContextSetRGBFillColor(ctx, 1.0, 1.0, 1.0, 1.0);
     CGContextFillRect(ctx, CGContextGetClipBoundingBox(ctx));
     CGContextTranslateCTM(ctx, 0.0, layer.bounds.size.height);
     CGContextScaleCTM(ctx, 1.0, -1.0);
     CGContextConcatCTM(ctx, CGPDFPageGetDrawingTransform(myPageRef, kCGPDFCropBox, layer.bounds, 0, true));
     CGContextDrawPDFPage(ctx, myPageRef);

Please help me to solve this problem.Thank u in advance.

Answer 1

CGPDFPageGetDrawingTransform does not scale your pdf up – you need to write your own transform code to calculate the best aspect ratio for the pdf.

Note that CGPDFPageGetDrawingTransform also checks for rotation in the pdf, you can use sth like this to correct it manually:

int rotate = CGPDFPageGetRotationAngle(page);
    switch (rotate) {
        case 0:
            renderingSize.width = roundf(cropBox.size.width * zoom / 100);
            renderingSize.height = roundf(cropBox.size.height * zoom / 100);
            CGContextTranslateCTM(context, 0, cropBox.size.height);
            CGContextScaleCTM(context, 1, -1);
            break;
        case 90:
            renderingSize.width = roundf(cropBox.size.height * zoom / 100);
            renderingSize.height = roundf(cropBox.size.width * zoom / 100);
            CGContextScaleCTM(context, 1, -1);
            CGContextRotateCTM(context, -M_PI / 2.f);
            break;
        case 180:
        case -180:
            renderingSize.width = roundf(cropBox.size.width * zoom / 100);
            renderingSize.height = roundf(cropBox.size.height * zoom / 100);
            CGContextScaleCTM(context, 1, -1);
            CGContextTranslateCTM(context, cropBox.size.width, 0);
            CGContextRotateCTM(context, M_PI * 1.f);
            break;
        case 270:
        case -90:
            renderingSize.width = roundf(cropBox.size.height * zoom / 100);
            renderingSize.height = roundf(cropBox.size.width * zoom / 100);
            CGContextTranslateCTM(context, cropBox.size.height, cropBox.size.width);
            CGContextRotateCTM(context, M_PI / 2.f);
            CGContextScaleCTM(context, -1, 1);
            break;
    }