LFILTER

Apply a filter to a layer. * Syntax ```sbsyntax LFILTER id% {, filterType%, filterParams... } LFILTER id% OUT filterType% ``` |* Argument | Description | | `id%` | The ID of the target layer. | | `filterType%` | The type of filter to apply to the layer.\ {|* Value | Description | | 0 | No filter | | 1 | Mosaic | | 2 | Blur | | 3 | Horizontal Raster Deformation | | 4 | Vertical Raster Deformation | | 5 | HSV Color Shift |} Optional. 0, if not specified. | | `filterParams...` | Parameters to the specified filter.\ The number and type of parameters depends on `filterType%`. See following sections for details on filters. | If `filterType%` and `filterParams...` are not specified, the filter is cleared. * Filters The following sections specify how each layer filter is used. ** No Filter The filter settings for the layer are reset. ```sbsyntax LFILTER id%, 0 ``` |* Input | Description | | `id%` | The ID of the target layer. | | `0` | Specify 0 for `filterType%` to clear the filter. | ** Mosaic Apply a "pixelated" effect to the layer by downsampling the image. ```sbsyntax LFILTER id%, 1, factor% ``` |* Input | Description | | `id%` | The ID of the target layer. | | `1` | Specify 1 for `filterType%` to use the mosaic filter. | | `factor%` | The amount of downsampling to apply.\ 1 = no change. | ** Blur Blur the layer. ```sbsyntax LFILTER id%, 2, amount% ``` |* Input | Description | | `id%` | The ID of the target layer. | | `2` | Specify 2 for `filterType%` to use the blur filter. | | `amount%` | The amount of blur to apply.\ 0 = no change. | ** Horizontal/Vertical Raster Deformation Apply offset and scaling to each row or column of pixels. ```sbsyntax LFILTER id%, 3, deformArray#[], repeatFlag% LFILTER id%, 4, deformArray#[], repeatFlag% ``` |* Input | Description | | `id%` | The ID of the target layer. | | `3`, `4` | Specify 3 for `filterType%` to use the horizontal deformation filter.\ Specify 4 for `filterType%` to use the vertical deformation filter. | | `deformArray#[]` | A 2D real number array containing deformation information. | | `repeatFlag%` | When true, the layer's contents will be repeated if the deformation samples outside the layer. | The first dimension of `deformArray#[]` must be the display's height (in pixels) for horizontal deformation and the display's width for vertical deformation. These correspond to each row or column of the display, respectively. The second dimension must be 2 or 4. If it is 2, then offset and scale are specified only for the X direction (horizontal deform) or Y direction (vertical deform) of each row/column. If it is 4, then offset and scale can be specified in both the X and Y directions. To sum up, here is a table of what each index refers to in the four possible modes. |* {#sup Filter}/{#sub Index} | Horizontal 2 | Vertical 2 | Horizontal 4 | Vertical 4 | |#h 0 | Row X offset | Column Y offset | Row X offset | Column X offset | |#h 1 | Row X scale | Column Y offset | Row X scale | Column X scale | |#h 2 | /unused/ | /unused/ | Row Y offset | Column Y offset | |#h 3 | /unused/ | /unused/ | Row Y scale | Column Y scale | Offset values are specified as real numbers, where 1.0 is the width/height of the display, depending on axis. ** HSV Color Shift Change the colors of the image by adjusting the HSV values. ```sbsyntax LFILTER id%, 5, hue#, saturation#, value# ``` |* Input | Description | | `id%` | The ID of the target layer. | | `5` | Specify 2 for `filterType%` to use the blur filter. | | `hue#` | Amount to adjust the hue by. | | `saturation#` | Amount to adjust the saturation by. | | `value#` | Amount to adjust the value (brightness) by. | * Examples Each example will demonstrate a different filter individually, using a given sample image. The sample image, and the code that generates it, is below. ```sb4 ACLS FOR I%=0 TO 239 GLINE 0,I%,399,I%,RGBF(0,I%/239,1) NEXT I% GTRI 150,170,150,70,250,120,#C_RED GTRI 250,170,250,70,150,120,#C_BLUE,#G_ADD TFILL 0,18,8,22,12,&hE801 SPSET 0,0:SPOFS 0,32,64:SPHOME 0,8,8 SPSET 1,1:SPOFS 1,64,64:SPHOME 1,8,8:SPSCALE 1,2:SPROT 1,45 SPSET 2,2:SPOFS 2,112,64:SPHOME 2,8,8:SPSCALE 2,3,3:SPROT 2,90 LOCATE 18,2 PRINT "Hello, "; COLOR #C_BLACK PRINT" World!" ``` !https://smilebasicsource.com/api/file/raw/3346#img ** Mosaic ```sb4 'apply a mosaic with 5x downsampling LFILTER 0,1,5 ``` !https://smilebasicsource.com/api/file/raw/3347#img ** Blur ```sb4 'apply a blur with a strength of 50 LFILTER 0,2,50 ``` !https://smilebasicsource.com/api/file/raw/3348#img ** Horizontal Raster Deformation ```sb4 'horizontal sine distortion 'declare filter params array [height of screen,2] DIM FP#[240,2] 'set params for each row of screen FOR I%=0 TO 239 'shift row horizontally by sine function FP#[I%,0]=SIN(I%/120*#PI)/8 'keep scale the same FP#[I%,1]=1 NEXT I% 'apply filter, enable wrapping LFILTER 0,3,FP#,#TRUE ``` !https://smilebasicsource.com/api/file/raw/3349#img ** Vertical Raster Deformation ```sb4 'vertical sine distortion 'declare filter params array [width of screen,2] DIM FP#[400,2] 'set params for each column of screen FOR I%=0 TO 399 'shift row horizontally by sine function FP#[I%,0]=SIN(I%/200*#PI)/8 'keep scale the same FP#[I%,1]=1 NEXT I% 'apply filter, enable wrapping LFILTER 0,4,FP#,#TRUE ``` !https://smilebasicsource.com/api/file/raw/3350#img ** HSV Color Shift ```sb4 'shift hue by 180 degrees 'shift saturation by -50 'shift value by 86 LFILTER 0,5,180,-50,86 ``` !https://smilebasicsource.com/api/file/raw/3351#img