tileSaver // issue with transparency

Programming Questions

pedroam

tileSaver // issue with transparency

in Programming Questions • 1 month ago

Hello guys,

i'm using this code example ( https://github.com/shengpo/processing_snips/tree/master/aTileSaverSimpleTest) to capture a high resolution image of my sketch.

i need my .tga file to have only a square draw with a transparent background. but once i remove the line of code that draws the background on my draw function, the tiler saver behaves in a strange way…

can you try it and see what could be a possible solution?

thanks in advance!

here is my code :

1. press 't' to export the .tga file.

2. i'm drawing the background and the rectangle on the lines 23-26

3. most part of the code is related with the class that creates the .tga file

aTileSaver tiler;
boolean savingPNG;
boolean letsSaveIt = false;
String location;
void setup() {
size(500, 500, P3D);
noStroke();
tiler=new aTileSaver(this);
location = null;
}
public void draw() {
if (tiler==null) return; // Not initialized
// call aTileSaver.pre() to prepare frame and setup camera if it exists.
tiler.pre();
background(0, 50, 0);
lights();
fill(255, 150, 0, 220);
rect(width/2, height/2, 90, 90);
// call aTileSaver.post() to update tiles if tiler is active
tiler.post();
if (letsSaveIt == true) {
tiler.init("Simple"+nf(frameCount, 3), 3);
letsSaveIt = false;
}
}
// Saves tiled imaged when 't' is pressed
public void keyPressed() {
if (key=='t') {
selectFolder("Select a folder to process:", "folderSelected");
}
}
class aTileSaver {
public boolean isTiling=false, done=true;
public boolean doSavePreview=true;
PApplet p;
float FOV=60; // initial field of view
float cameraZ, width, height;
int tileNum=10, tileNumSq; // number of tiles
int tileImgCnt, tileX, tileY;
boolean firstFrame=false, secondFrame=false;
String tileFilename, tileFileExt=".tga";
//String tileFilename, tileFileExt=".png";
PImage tileImg;
float perc, percMilestone;
boolean savingPNG = false;
// The constructor takes a PApplet reference to your sketch.
public aTileSaver(PApplet _p) {
p=_p;
}
public void gettingLocation(){
selectFolder("Select a folder to process:", "folderSelected");
}
// If init() is called without specifying number of tiles, getMaxTiles()
// will be called to estimate number of tiles according to free memory.
public void init(String _filename) {
init(_filename, getMaxTiles(p.width));
}
// Initialize using a filename to output to and number of tiles to use.
public void init(String _filename, int _num) {
tileFilename=_filename;
tileNum=_num;
tileNumSq=(tileNum*tileNum);
width=p.width;
height=p.height;
cameraZ=(height/2.0f)/p.tan(p.PI*FOV/360.0f);
p.println("aTileSaver: "+tileNumSq+" tiles and Resolution: "+(p.width*tileNum)+"x"+(p.height*tileNum));
// remove extension from filename
if (!new java.io.File(tileFilename).isAbsolute())
tileFilename=p.dataPath(tileFilename);
tileFilename=noExt(tileFilename);
p.createPath(tileFilename);
// save preview
p.g.save(location + "/myPreview.png");
// set up off-screen buffer for saving tiled images
tileImg=new PImage(p.width*tileNum, p.height*tileNum);
// start tiling
isTiling=true;
firstFrame=true; //for skip first frame after do tiling
secondFrame=true; //for skip second frame after do tiling
tileImgCnt=0;
tileX = 0;
tileY = 0;
done=false;
perc=0;
percMilestone=0;
}
// set filetype, default is TGA. pass a valid image extension as parameter.
public void setSaveType(String extension) {
tileFileExt=extension;
if (tileFileExt.indexOf(".")==-1) tileFileExt="."+tileFileExt;
}
// pre() handles initialization of each frame.
// It should be called in draw() before any drawing occurs.
public void pre() {
if (!isTiling) return;
if (firstFrame) {
firstFrame=false;
}
else if (secondFrame) {
secondFrame=false;
}
setupCamera();
}
// post() handles tile update and image saving.
// It should be called at the very end of draw(), after any drawing.
public void post() {
// If first or second frame, don't update or save.
if (firstFrame || secondFrame || (!isTiling)) return;
// Get current image from sketch and draw it into buffer
p.loadPixels();
tileImg.set(tileX*p.width, tileY*p.height, p.g);
// Increment tile index
tileImgCnt++;
perc=100*((float)tileImgCnt/(float)tileNumSq);
if (perc-percMilestone> 5 || perc>99) {
p.println(p.nf(perc, 3, 2)+"% completed. "+tileImgCnt+"/"+tileNumSq+" images saved.");
percMilestone=perc;
}
if (tileImgCnt==tileNumSq) tileFinish();
else tileInc();
}
public boolean checkStatus() {
return isTiling;
}
// tileFinish() handles saving of the tiled image
public void tileFinish() {
isTiling=false;
restoreCamera();
// save large image to TGA
tileFilename+="_"+(p.width*tileNum)+"x"+(p.height*tileNum)+tileFileExt;
p.println("Save: "+tileFilename.substring(tileFilename.lastIndexOf(java.io.File.separator)+1));
tileImg.save(location + "/test.tga");
p.println("Done tiling.n");
// clear buffer for garbage collection
tileImg=null;
done=true;
}
// Increment tile coordinates
public void tileInc() {
if (tileX==tileNum-1) {
tileX=0;
tileY=(tileY+1)%tileNum;
}
else {
tileX++;
}
}
// set up camera correctly for the current tile
//caution: camera's coordination system si different from drawing's coordination system
// so, must be very care of parameters in camera() and frustum() !!
public void setupCamera() {
//reset to default camera coordination with Y-UP (up-increase), and original poit is at (width/2f, height/2f, 0)
p.camera(width/2.0f, height/2.0f, cameraZ, width/2.0f, height/2.0f, 0, 0, 1, 0);
if (isTiling) {
//set to a specific perspective (or clipping volume) with enough near near-plane and enough far far-plane
//this step is to fix the viewport on each tile
float mod=1f/10f; //to make near plane is close to camera(aka eye)
p.frustum((-width/2f + width*((float)tileX/(float)tileNum))*mod, //left
(-width/2f + width*((tileX+1)/(float)tileNum))*mod, //right
(height/2f - height*((tileY+1)/(float)tileNum))*mod, //bottom
(height/2f - height*((float)tileY/(float)tileNum))*mod, //up
cameraZ*mod, 10000); //near, far
}
}
// restore camera once tiling is done
public void restoreCamera() {
//reset to default camera coordination with Y-UP (up-increase), and original poit is at (width/2f, height/2f, 0)
p.camera(width/2.0f, height/2.0f, cameraZ, width/2.0f, height/2.0f, 0, 0, 1, 0);
//reset to default perspective (or clipping volume) with enough near near-plane and enough far far-plane
float mod=1f/10f; //to make near plane is close to camera(aka eye)
p.frustum(-(width/2)*mod, (width/2)*mod, //left, right
-(height/2)*mod, (height/2)*mod, //bottom, up
cameraZ*mod, 10000); //near, far
}
// checks free memory and gives a suggestion for maximum tile
// resolution. It should work well in most cases, I've been able
// to generate 20k x 20k pixel images with 1.5 GB RAM allocated.
public int getMaxTiles(int width) {
// get an instance of java.lang.Runtime, force garbage collection
java.lang.Runtime runtime=java.lang.Runtime.getRuntime();
runtime.gc();
// calculate free memory for ARGB (4 byte) data, giving some slack
// to out of memory crashes.
int num=(int)(Math.sqrt((float)(runtime.freeMemory()/4)*0.925f))/width;
p.println(((float)runtime.freeMemory()/(1024*1024))+"/"+((float)runtime.totalMemory()/(1024*1024)));
// warn if low memory
if (num==1) {
p.println("Memory is low. Consider increasing memory.");
num=2;
}
return num;
}
// strip extension from filename
String noExt(String name) {
int last=name.lastIndexOf(".");
if (last>0)
return name.substring(0, last);
return name;
}
}
public void folderSelected(File selection) {
if (selection == null) {
println("Window was closed or the user hit cancel.");
location = "";
}
else {
location = selection.getAbsolutePath();
println(location);
letsSaveIt = true;
}
}

Replies(1)

dimkir

Re: tileSaver // issue with transparency

1 month ago

Screen buffer doesn't have such concept as "transparency". There should always be some background. If you don't call to background() then it will use "uninitialized" value for background and it will result in unexpected behavour varying from platform to platform.

If you want to have things transparent, you need to createGraphics() with P3D renderer and then cast it to PGLGraphics and after that modify tileSaver to use this graphics instead of the default one. That may work out.

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