I'm trying to use cvFindContours, which definitely seems like the way to go. I'm having a problem with getting the largest one. There is a function call cvContourArea, which suppose to get the area of a contour in a sequence. I'm having trouble with it.
int conNum = cvFindContours(outerbox, storage, &contours, sizeof(CvContour),CV_RETR_LIST,CV_CHAIN_APPROX_NONE,cvPoint(0, 0));
CvSeq* current_contour = contours;
double largestArea = 0;
CvSeq* largest_contour = NULL;
while (current_contour != NULL){
double area = fabs(cvContourArea(&storage,CV_WHOLE_SEQ, false));
if(area > largestArea){
largestArea = area;
largest_contour = current_contour;
}
current_contour = current_contour->h_next;
}
I tried replacing storage (in the cvContourArea) with contours, but same error keeps coming up no matter what:
OpenCV Error: Bad argument (Input array is not a valid matrix) in cvPointSeqFromMat, file /Volumes/ramdisk/opencv/OpenCV-2.2.0/modules/imgproc/src/utils.cpp, line 53
I googled and could hardly find example of cvContourArea that takes 3 arguments.. as if it's changed recently.. I want to loop thru the found contours and find the biggest one and after that draw it using the cvDrawContours method.. Thanks!
Try to change &storage to current_contour in the following statement.
Change
double area = fabs(cvContourArea(&storage,CV_WHOLE_SEQ, false));
to
double area = fabs(cvContourArea(current_contour,CV_WHOLE_SEQ, 0));
Related
I currently have a big question for writing code for button commands and direction arrays. I write code for a horizontal button array that is in the form of something like this:
for (var i = 0; i < array_length_1d(left); i ++;){
if (keyboard_check(left[i])){
x -= spd;
break;
}
}
Then I create vertical button arrays where thew upward button array is correct but the downward button array is incorrect while distributing this code:
for (var i = 0; i < array_length_1d(down); i ++;){
if (keyboard_check(down[i])){
y += spd;
break;
}
}
When I try and Run the game, it shows this error:
FATAL ERROR in
action number 1
of Step Event0
for object obj_player:
Variable obj_player.down(100008, -2147483648) not set before reading it.
at gml_Object_obj_player_Step_0 (line 25) - for (var i = 0; i < array_length_1d(down); i ++;){
What am I doing wrong?
Check where you have defined you down variable and see what's different about it compared with the left variable.
The error shows that the down is not yet defined by the time it's about to use it.
When I attempt to update my mouse position from the lLastX, and lLastY members of the RAWMOUSE structure while I'm logged in via RDP, I get some really odd numbers (like > 30,000 for both). I've noticed this behavior on Windows 7, 8, 8.1 and 10.
The usFlags member returns a value of MOUSE_MOVE_ABSOLUTE | MOUSE_VIRTUAL_DESKTOP. Regarding the MOUSE_MOVE_ABSOLUTE, I am handling absolute positioning as well as relative in my code. However, the virtual desktop flag has me a bit confused as I assumed that flag was for a multi-monitor setup. I've got a feeling that there's a connection to that flag and the weird numbers I'm getting. Unfortunately, I really don't know how to adjust the values without a point of reference, nor do I even know how to get a point of reference.
When I run my code locally, everything works as it should.
So does anyone have any idea why RDP + Raw Input would give me such messed up mouse lastx/lasty values? And if so, is there a way I can convert them to more sensible values?
It appears that when using WM_INPUT through remote desktop, the MOUSE_MOVE_ABSOLUTE and MOUSE_VIRTUAL_DESKTOP bits are set, and the values seems to be ranging from 0 to USHRT_MAX.
I never really found a clear documentation stating which coordinate system is used when MOUSE_VIRTUAL_DESKTOP bit is set, but this seems to have worked well thus far:
case WM_INPUT: {
UINT buffer_size = 48;
LPBYTE buffer[48];
GetRawInputData((HRAWINPUT)lparam, RID_INPUT, buffer, &buffer_size, sizeof(RAWINPUTHEADER));
RAWINPUT* raw = (RAWINPUT*)buffer;
if (raw->header.dwType != RIM_TYPEMOUSE) {
break;
}
const RAWMOUSE& mouse = raw->data.mouse;
if ((mouse.usFlags & MOUSE_MOVE_ABSOLUTE) == MOUSE_MOVE_ABSOLUTE) {
static Vector3 last_pos = vector3(FLT_MAX, FLT_MAX, FLT_MAX);
const bool virtual_desktop = (mouse.usFlags & MOUSE_VIRTUAL_DESKTOP) == MOUSE_VIRTUAL_DESKTOP;
const int width = GetSystemMetrics(virtual_desktop ? SM_CXVIRTUALSCREEN : SM_CXSCREEN);
const int height = GetSystemMetrics(virtual_desktop ? SM_CYVIRTUALSCREEN : SM_CYSCREEN);
const Vector3 absolute_pos = vector3((mouse.lLastX / float(USHRT_MAX)) * width, (mouse.lLastY / float(USHRT_MAX)) * height, 0);
if (last_pos != vector3(FLT_MAX, FLT_MAX, FLT_MAX)) {
MouseMoveEvent(absolute_pos - last_pos);
}
last_pos = absolute_pos;
}
else {
MouseMoveEvent(vector3((float)mouse.lLastX, (float)mouse.lLastY, 0));
}
}
break;
I am using the SoXR library's variable rate feature to dynamically change the sampling rate of an audio stream in real time. Unfortunately I have have noticed that an unwanted clicking noise is present when changing the rate from 1.0 to a larger value (ex: 1.01) when testing with a sine wave. I have not noticed any unwanted artifacts when changing from a value larger than 1.0 to 1.0. I looked at the wave form it was producing and it appeared as if a few samples right at rate change are transposed incorrectly.
Here's a picture of an example of a stereo 440Hz sinewave stored using signed 16bit interleaved samples:
I also was unable to find any documentation covering the variable rate feature beyond the fifth code example. Here's is my initialization code:
bool DynamicRateAudioFrameQueue::intialize(uint32_t sampleRate, uint32_t numChannels)
{
mSampleRate = sampleRate;
mNumChannels = numChannels;
mRate = 1.0;
mGlideTimeInMs = 0;
// Intialize buffer
size_t intialBufferSize = 100 * sampleRate * numChannels / 1000; // 100 ms
pFifoSampleBuffer = new FiFoBuffer<int16_t>(intialBufferSize);
soxr_error_t error;
// Use signed int16 with interleaved channels
soxr_io_spec_t ioSpec = soxr_io_spec(SOXR_INT16_I, SOXR_INT16_I);
// "When creating a var-rate resampler, q_spec must be set as follows:" - example code
// Using SOXR_VR makes sense, but I'm not sure if the quality can be altered when using var-rate
soxr_quality_spec_t qualitySpec = soxr_quality_spec(SOXR_HQ, SOXR_VR);
// Using the var-rate io-spec is undocumented beyond a single code example which states
// "The ratio of the given input rate and ouput rates must equate to the
// maximum I/O ratio that will be used: "
// My tests show this is not true
double inRate = 1.0;
double outRate = 1.0;
mSoxrHandle = soxr_create(inRate, outRate, mNumChannels, &error, &ioSpec, &qualitySpec, NULL);
if (error == 0) // soxr_error_t == 0; no error
{
mIntialized = true;
return true;
}
else
{
return false;
}
}
Any idea what may be causing this to happen? Or have a suggestion for an alternative library that is capable of variable rate audio resampling in real time?
After speaking with the developer of the SoXR library I was able to resolve this issue by adjusting the maximum ratio parameters in the soxr_create method call. The developer's response can be found here.
I want to make a cave explorer game in game maker 8.0.
I've made a block object and an generator But I'm stuck. Here is my code for the generator
var r;
r = random_range(0, 1);
repeat(room_width/16) {
repeat(room_height/16) {
if (r == 1) {
instance_create(x, y, obj_block)
}
y += 16;
}
x += 16;
}
now i always get a blank frame
You need to use irandom(1) so you get an integer. You also should put it inside the loop so it generates a new value each time.
In the second statement, you are generating a random real value and storing it in r. What you actually require is choosing one of the two values. I recommend that you use the function choose(...) for this. Here goes the corrected statement:
r = choose(0,1); //Choose either 0 or 1 and store it in r
Also, move the above statement to the inner loop. (Because you want to decide whether you want to place a block at the said (x,y) location at every spot, right?)
Also, I recommend that you substitute sprite_width and sprite_height instead of using the value 16 directly, so that any changes you make to the sprite will adjust the resulting layout of the blocks accordingly.
Here is the code with corrections:
var r;
repeat(room_width/sprite_width) {
repeat(room_height/sprite_height) {
r = choose(0, 1);
if (r == 1)
instance_create(x, y, obj_block);
y += sprite_height;
}
x += sprite_width;
}
That should work. I hope that helps!
Looks like you are only creating a instance if r==1. Shouldn't you create a instance every time?
Variable assignment r = random_range(0, 1); is outside the loop. Therefore performed only once before starting the loop.
random_range(0, 1) returns a random real number between 0 and 1 (not integer!). But you have if (r == 1) - the probability of getting 1 is a very small.
as example:
repeat(room_width/16) {
repeat(room_height/16) {
if (irandom(1)) {
instance_create(x, y, obj_block)
}
y += 16;
}
x += 16;
}
Here's a possible, maybe even better solution:
length = room_width/16;
height = room_height/16;
for(xx = 0; xx < length; xx+=1)
{
for(yy = 0; yy < height; yy+=1)
{
if choose(0, 1) = 1 {
instance_create(xx*16, yy*16, obj_block); }
}
}
if you want random caves, you should probably delete random sections of those blocks,
not just single ones.
For bonus points, you could use a seed value for the random cave generation. You can also have a pathway random generation that will have a guaranteed path to the finish with random openings and fake paths that generate randomly from that path. Then you can fill in the extra spaces with other random pieces.
But in regards to your code, you must redefine the random number each time you are placing a block, which is why all of them are the same. It should be called inside of the loops, and should be an integer instead of a decimal value.
Problem is on the first line, you need to put r = something in the for cycle
I am basically trying to obtain the samples produced by an AUGraph using a GenericOutput Node and a call to AudioUnitRender. As a starting point for my program I used the MixerHost example by Apple and changed the outputNode as follows.
AudioComponentDescription iOUnitDescription;
iOUnitDescription.componentType = kAudioUnitType_Output;
iOUnitDescription.componentSubType = kAudioUnitSubType_GenericOutput;
iOUnitDescription.componentManufacturer = kAudioUnitManufacturer_Apple;
iOUnitDescription.componentFlags = 0;
iOUnitDescription.componentFlagsMask = 0;
Later when I want to obtain my samples, I call
AudioUnitRenderActionFlags ioActionFlags = kAudioOfflineUnitRenderAction_Render;
AudioTimeStamp inTimeStamp = {0};
inTimeStamp.mHostTime = mach_absolute_time();
inTimeStamp.mFlags = kAudioTimeStampSampleHostTimeValid;
result = AudioUnitRender (
ioUnit,
&ioActionFlags,
&inTimeStamp,
1,
1024,
ioData
);
which yields an
"-10877 / Invalid Element"
error. My assumption is, that the error comes from not setting the inTimeStamp.mSampleTime field correctly. To be honest, I have not found a way to find out the sample time other than AudioQueueDeviceGetCurrentTime, which I cannot use, since I do not use an AudioQueue. However changing the ioActionFlag to kAudioTimeStampHostTimeValid does not change the the error behaviour.
The error pertaining to the element (AKA 'bus') refers to the 4th argument (1) to your AudioUnitRender call. The Generic Output unit only has one element/bus: 0 which has an input, output and global scope. If you pass 0 to the call instead of 1 for the element #, that error should disappear.