how to scale an image

[akabeer1983]

Hi,
i am programming for iPhone, i want to scale an image, based on user's touch (touch one corner of image and drag it).
how can i scale the image.
i tried the following, but it displays nothing:

//member variables declaration part
E2DBLTFX bltfx;

//constructor
bltfx.xscale = 3;
bltfx.yscale = 3;

//OnNextFrame function
display -> BltFx(10, 10, image, &rect, &bltfx);


But there wsa no problem with rendering the image normally:
display -> BltFast(100, 100, image, &rect)
the above statement displays the image properly.

[edge]

Hi,

Your scale values are too small, which makes the image invisible. To scale, use the following formula's:

Code: Select all

1  2	bltfx.xscale = 3 * 65536; //300% bltfx.xscale = 65536 / 2; //50%
	2 lines; 0 keywds; 4 nums; 8 ops; 0 strs; 2 coms    Syntactic Coloring v0.4 - Dan East

[akabeer1983]

i also tried the following, but nothing dislayed;
display -> Blt(0, 0, image, &rect, 0, 65536, EFLIP_HORIZONTAL);
i also tried various other values for rotation, sclaing, but in vain.

[akabeer1983]

Hi,
thanks for reply
it worked with:
bltfx.xscale = 3 * 65536;// (300%)
for both Blt and Btlfx functions.
Thanks