Color matrix to change dark color - actionscript-3

I try to make a function to colorize image - desaturate and replace dark color with supplied RGB color.
I have found similar function from Mario Klingemann AS3 ColorMatrix library, which replace light color while preserving dark.
public function colorize(rgb:int, amount:Number=1):void
{
const LUMA_R:Number = 0.212671;
const LUMA_G:Number = 0.71516;
const LUMA_B:Number = 0.072169;
var r:Number;
var g:Number;
var b:Number;
var inv_amount:Number;
r = (((rgb >> 16) & 0xFF) / 0xFF);
g = (((rgb >> 8) & 0xFF) / 0xFF);
b = ((rgb & 0xFF) / 0xFF);
inv_amount = (1 - amount);
concat([(inv_amount + ((amount * r) * LUMA_R)), ((amount * r) * LUMA_G), ((amount * r) * LUMA_B), 0, 0,
((amount * g) * LUMA_R), (inv_amount + ((amount * g) * LUMA_G)), ((amount * g) * LUMA_B), 0, 0,
((amount * b) * LUMA_R), ((amount * b) * LUMA_G), (inv_amount + ((amount * b) * LUMA_B)), 0, 0,
0, 0, 0, 1, 0]);
}
I tried to modify the matrix but with no success. Please could you provide me any help or link to information or code that make me move forward a bit.

You could try to use the method above, but before you apply it you invert the image and the color. Then after applying the matrix, you invert the image again.

After all I found the trick in this result:
concat([(LUMA_R), (LUMA_G), (LUMA_B), 0, amount*255*r,
(LUMA_R), (LUMA_G), (LUMA_B), 0, amount*255*g,
(LUMA_R), (LUMA_G), (LUMA_B), 0, amount*255*b,
0, 0, 0, 1, 0]);
It does exactly what I needed.
Thanks to Quasimondo for his great AS3 library. Helped me a lot in understanding the color matrix transformations.

Related

cocos2dx-3.10 covertToWorldSpace result is wrong when using OrbitCamera

cocos2dx-3.10 covertToWorldSpace result is wrong when using OrbitCamera
devices test on:Windows
Steps to Reproduce:
local size = cc.size(400, 400)
local layer = cc.LayerColor:create(cc.c4b(200, 0, 0, 255), size.width, size.height)
layer:setPosition(display.cx - size.width, display.cy - size.height)
self:addChild(layer)
local label = cc.Label:create()
label:setSystemFontSize(30)
label:setSystemFontName("Arial")
label:setString("XXX")
label:setColor(cc.c3b(0, 255, 100))
label:setPosition(size.width * 0.5, 0)
layer:addChild(label)
local lsize = label:getContentSize()
local action = cc.OrbitCamera:create(1, 1, 0, 0, 70, -90, 0)
local callFunc = cc.CallFunc:create(function()
local worldPos = label:convertToWorldSpace(cc.p(lsize.width * 0.5, lsize.height * 0.5))
label = cc.Label:create()
label:setSystemFontSize(30)
label:setSystemFontName("Arial")
label:setString("AAA")
label:setColor(cc.c3b(100, 0, 100))
label:setPosition(worldPos)
self:addChild(label)
end)
layer:runAction(cc.Sequence:create(action, callFunc))
I found a solution:
local mat4 = label:getNodeToParentTransform(self)
local vec4 = {x = lsize.width * 0.5, y = lsize.height * 0.5, z = 0, w = 1}
-- convert to world space (we need to calculate its Z-value)
local pos = mat4_transformVector(mat4, vec4, cc.mat4.createIdentity())
-- convert GL-screen-space coordinates
local worldPos = cc.Camera:getDefaultCamera():projectGL(pos)
enter image description here

cuda - directx 12 texture2D (in 1D array) interop

I'm trying to update in cuda a texture used in directx12. I may miss something but I have no tip about it.
there is an "all the time black" area in the top right area of the image.
only when I have R G B having the same value for all pixels, I get the expected result (modulo the first problem), if not I have unexpected artefacts, as if the array was not having the expected structure.
What do I miss ?
Here is the creation of the texture:
{
TextureWidth = m_width;
TextureHeight = m_height;
auto nPixels = TextureWidth * TextureHeight * 3;
auto pixelBufferSize = sizeof(float)* nPixels;
D3D12_RESOURCE_DESC textureDesc{};
textureDesc.MipLevels = 1;
textureDesc.Format = DXGI_FORMAT_R32G32B32_FLOAT;
textureDesc.Width = TextureWidth;
textureDesc.Height = TextureHeight;
textureDesc.Flags = D3D12_RESOURCE_FLAG_NONE;
textureDesc.DepthOrArraySize = 1;
textureDesc.SampleDesc.Count = 1;
textureDesc.SampleDesc.Quality = 0;
textureDesc.Dimension = D3D12_RESOURCE_DIMENSION_TEXTURE2D;
ThrowIfFailed(m_device->CreateCommittedResource(&CD3DX12_HEAP_PROPERTIES(D3D12_HEAP_TYPE_DEFAULT), D3D12_HEAP_FLAG_SHARED,
&textureDesc, D3D12_RESOURCE_STATE_PIXEL_SHADER_RESOURCE, nullptr, IID_PPV_ARGS(&m_textureBuffer)));
NAME_D3D12_OBJECT(m_textureBuffer);
// Describe and create a SRV for the texture.
{
D3D12_SHADER_RESOURCE_VIEW_DESC srvDesc{};
srvDesc.Shader4ComponentMapping = D3D12_DEFAULT_SHADER_4_COMPONENT_MAPPING;
srvDesc.Format = textureDesc.Format;
srvDesc.ViewDimension = D3D12_SRV_DIMENSION_TEXTURE2D;
srvDesc.Texture2D.MipLevels = 1;
m_device->CreateShaderResourceView(m_textureBuffer.Get(), &srvDesc, m_srvHeap->GetCPUDescriptorHandleForHeapStart());
NAME_D3D12_OBJECT(m_srvHeap);
}
// Share m_textureBuffer with cuda
{
HANDLE sharedHandle{};
WindowsSecurityAttributes windowsSecurityAttributes{};
LPCWSTR name{};
ThrowIfFailed(m_device->CreateSharedHandle(m_textureBuffer.Get(), &windowsSecurityAttributes, GENERIC_ALL, name, &sharedHandle));
D3D12_RESOURCE_ALLOCATION_INFO d3d12ResourceAllocationInfo;
d3d12ResourceAllocationInfo = m_device->GetResourceAllocationInfo(m_nodeMask, 1, &CD3DX12_RESOURCE_DESC::Buffer(pixelBufferSize));
auto actualSize = d3d12ResourceAllocationInfo.SizeInBytes;
cudaExternalMemoryHandleDesc externalMemoryHandleDesc;
memset(&externalMemoryHandleDesc, 0, sizeof(externalMemoryHandleDesc));
externalMemoryHandleDesc.type = cudaExternalMemoryHandleTypeD3D12Resource;
externalMemoryHandleDesc.handle.win32.handle = sharedHandle;
externalMemoryHandleDesc.size = actualSize;
externalMemoryHandleDesc.flags = cudaExternalMemoryDedicated;
checkCudaErrors(cudaImportExternalMemory(&m_externalMemory, &externalMemoryHandleDesc));
cudaExternalMemoryBufferDesc externalMemoryBufferDesc;
memset(&externalMemoryBufferDesc, 0, sizeof(externalMemoryBufferDesc));
externalMemoryBufferDesc.offset = 0;
externalMemoryBufferDesc.size = pixelBufferSize;
externalMemoryBufferDesc.flags = 0;
checkCudaErrors(cudaExternalMemoryGetMappedBuffer(&m_cudaDevVertptr, m_externalMemory, &externalMemoryBufferDesc));
RunKernel(TextureWidth, TextureHeight, (float*)m_cudaDevVertptr, m_streamToRun, 1.0f);
checkCudaErrors(cudaStreamSynchronize(m_streamToRun));
}
}
And here the cuda code for updating this texture:
int iDivUp(int a, int b) { return a % b != 0 ? a / b + 1 : a / b; }
__global__ void TextureKernel(float *pixels, unsigned int width, unsigned int height, float time)
{
unsigned int x = blockIdx.x*blockDim.x + threadIdx.x;
unsigned int y = blockIdx.y*blockDim.y + threadIdx.y;
if (y < height && x < width)
{
auto pos = (y * width + x) * 3;
auto sint = __sinf(time) * 0.1f + 0.10f;
auto sintAlt = (x / 32) % 2 == 0 ? 1.0f : sint;
pixels[pos + 0] = sintAlt; //RED
pixels[pos + 1] = 0; // (x + y) % 2 == 0 ? 1.0f : __sinf(time) * 0.25f + 0.75f; //GREEN
pixels[pos + 2] = 0; // (x + y) % 2 == 0 ? 1.0f : 0.0f; //BLUE
//pixels[pos + 0] = __sinf(time + 0.) * 0.5f + 0.5f;
//pixels[pos + 1] = __sinf(time * 0.09) * 0.5f + 0.5f;
//pixels[pos + 2] = __sinf(time + 2) * 0.5f + 0.5f;
}
}
void RunKernel(size_t meshWidth, size_t meshHeight, float *texture_dev, cudaStream_t streamToRun, float animTime)
{
//dim3 block(16, 16, 1);
//dim3 grid(meshWidth / 16, meshHeight / 16, 1);
auto unit = 32;
dim3 threads(unit, unit);
dim3 grid(iDivUp(meshWidth, unit), iDivUp(meshHeight, unit));
TextureKernel <<<grid, threads, 0, streamToRun >>>(texture_dev, meshWidth, meshHeight, animTime);
getLastCudaError("TextureKernel execution failed.\n");
}
And an extract of the resulting image I get with this code:
And the full repo if needed:
https://github.com/mprevot/CudaD3D12Update
EDIT
Two problems occur here.
The first is the format of texture: R32G32B32float, but the RTV (?) is expecting actually R32G32B32A32float. Matching everything at R32G32B32A32float can solve the weird colors arrays. The other way is to match the RTV to a R32G32B32float texture, but I don't see how.
The second problem is to work with cudaExternalMemoryGetMappedBuffer instead of cudaExternalMemoryGetMappedMipmappedArray; however how to use it with the texture described by D3D12_RESOURCE_DESC textureDesc{}; as well as a 1D cuda array float* is no clear yet.
I tried with the following code (for a 1D mipmap array), without success (cudaErrorInvalidValue).
auto textureSurface = TextureWidth * TextureHeight;
auto texturePixels = textureSurface * TextureChannels;
cudaExternalMemoryMipmappedArrayDesc cuTexDesc{};
cuTexDesc.numLevels = 1;
cuTexDesc.extent = make_cudaExtent(texturePixels, 0, 0);
cuTexDesc.formatDesc = cudaCreateChannelDesc<float>();
auto result = cudaMallocMipmappedArray(&cuMipArray[0], &cuTexDesc.formatDesc, cuTexDesc.extent, cuTexDesc.numLevels);
You assume that a 2D texture image with three channels of type float will have a simple row-wise linear memory layout. As demonstrated by your result, this is generally not true.
Textures are optimized for spatially-coherent access. Their memory layout is designed to keep things that are close in n-dimensional texture space close in memory. This cannot be achieved for anything with more than one dimension by a simple row-major memory layout. The exact memory layout of a particular texture image is generally not something you can assume to know or rely upon. It will depend on the GPU you're using (typically, the data will be stored in some way that employs things like tiling or Morton order, with padding in places to keep stuff aligned).
As you noticed yourself, what you want to do is use cudaExternalMemoryGetMappedMipmappedArray() to map a CUDA array (arrays are the CUDA-analogon to texture images) to your external data coming from D3D12. The format of this CUDA array will have to match the format of the texture created in D3D12. You should then be able to use the texture or surface functions of the CUDA runtime API to access the texture image represented by this CUDA array…
The right thing to do is to import the texture as external memory, then as mipmap array, then use this array to create a cuda surface, and then modify this surface in the cuda kernel.
The import and mapping is done this way:
cudaExternalMemoryMipmappedArrayDesc cuExtmemMipDesc{};
cuExtmemMipDesc.extent = make_cudaExtent(texDesc.Width, texDesc.Height, 0);
cuExtmemMipDesc.formatDesc = cudaCreateChannelDesc<float4>();
cuExtmemMipDesc.numLevels = 1;
cuExtmemMipDesc.flags = cudaArraySurfaceLoadStore;
cudaMipmappedArray_t cuMipArray{};
CheckCudaErrors(cudaExternalMemoryGetMappedMipmappedArray(&cuMipArray, m_externalMemory, &cuExtmemMipDesc));
cudaArray_t cuArray{};
CheckCudaErrors(cudaGetMipmappedArrayLevel(&cuArray, cuMipArray, 0));
cudaResourceDesc cuResDesc{};
cuResDesc.resType = cudaResourceTypeArray;
cuResDesc.res.array.array = cuArray;
checkCudaErrors(cudaCreateSurfaceObject(&cuSurface, &cuResDesc));
// where cudaSurfaceObject_t cuSurface{};
the cuda part looks like this:
int iDivUp(int a, int b) { return a % b != 0 ? a / b + 1 : a / b; }
__global__ void UpdateSurface(cudaSurfaceObject_t surf, unsigned int width, unsigned int height, float time)
{
unsigned int x = blockIdx.x * blockDim.x + threadIdx.x;
unsigned int y = blockIdx.y * blockDim.y + threadIdx.y;
if (y >= height | x >= width) return;
auto xVar = (float)x / (float)width;
auto yVar = (float)y / (float)height;
auto cost = __cosf(time) * 0.5f + 0.5f;
auto costx = __cosf(time) * 0.5f + xVar;
auto costy = __cosf(time) * 0.5f + yVar;
auto costxx = (__cosf(time) * 0.5f + 0.5f) * width;
auto costyy = (__cosf(time) * 0.5f + 0.5f) * height;
auto costxMany = __cosf(y * time) * 0.5f + yVar;
auto costyMany = __cosf((float)x/100 * time) * 0.5f + xVar;
auto margin = 1;
float4 pixel{};
if (y == 0) // paint the first row
pixel = make_float4(costyMany * 0.3, costyMany * 1, costyMany * 0.4, 1);
else if (y == height - 1) // paint the last row
pixel = make_float4(costyMany * 0.6, costyMany * 0.7, costyMany * 1, 1);
else if (x % 5 == 0) // paint a column of 1 pixel wide every 5 pixels
{
if (x > width / 2) // a certain color for the right half
pixel = make_float4(0.1, 0.5, costx * 1, 1);
else // another color for the left half
pixel = make_float4(costx * 1, 0.1, 0.2, 1);
}
else if (x > width - margin - 1 | x <= margin) // first and last columns
pixel = make_float4(costxMany, costxMany * 0.9, costxMany * 0.6, 1);
else // all the rest of the texture
pixel = make_float4(costx * 0.3, costx * 0.4, costx * 0.6, 1);
surf2Dwrite(pixel, surf, x * 16, y);
}
void RunKernel(size_t textureW, size_t textureH, cudaSurfaceObject_t surfaceObject, cudaStream_t streamToRun, float animTime)
{
auto unit = 10;
dim3 threads(unit, unit);
dim3 grid(iDivUp(textureW, unit), iDivUp(textureH, unit));
UpdateSurface <<<grid, threads, 0, streamToRun >>> (surfaceObject, textureW, textureH, animTime);
getLastCudaError("UpdateSurface execution failed.\n");
}
I updated the git repo to reflect those changes (https://github.com/mprevot/CudaD3D12Update)

HTML CSS3 / Canvas Image Distortion

Is there a way to skew/distort only one corner using CSS3 or canvas tag in HTML5?
Here is a screenshot from Photoshop tutorial how to do it:
Update:
This is the best I have found so far, but it is not 100% accurate:
https://github.com/edankwan/PerspectiveTransform.js
Update2:
I need html5 version of this:
http://www.rubenswieringa.com/code/as3/flex/DistortImage/
This should help you .
Link1
And you should try searching before posting a question. I searched for html5 canvas skew image and it showed me so many results .
Update
Check Out this Fiddle
// Find each img, and replace it with a canvas
$('img').each(function (index, el) {
var c, // new canvas which will replace this img element
ctx, // context of new canvas
i, // loop counter
tmpCtx, // temp context for doing work
h, // height of the image / new canvas
w, // width of the image / new canvas
dh, // destination height (used in translation)
dw, // destination width (used in translation)
dy, // destination y
leftTop,// left top corner position
leftBot;// left bottom corner position
// Get the height/width of the image
h = el.height;
w = el.width;
// Create the canvas and context that will replace the image
c = $("<canvas height='" + h + "' width='" + w + "'><\/canvas>");
ctx = c.get(0).getContext('2d');
// Create a temporary work area
tmpCtx = document.createElement('canvas').getContext('2d');
// Draw the image on the temp work area
for (i = 0; i < h; i++) {
dw = Math.abs((w * (h - i) + w * i) / h);
tmpCtx.drawImage(el,
0, i, w, 1, // sx, sy, sw, sh
0, i, dw, 1); // dx, dy, dw, dh
}
// Calculate the left corners to be 20% of the height
leftTop = parseInt(h * .2, 10);
leftBot = parseInt(h * 1, 10) - leftTop;
ctx.save();
// Draw the image on our real canvas
for (i = 0; i < w; i++) {
dy = (leftTop * (w - i)) / w;
dh = (leftBot * (w - i) + h * i) / w;
ctx.drawImage(tmpCtx.canvas,
i, 0, 1, h,
i, dy, 1, dh);
}
ctx.restore();
// Replace the image with the canvas version
$(el).replaceWith(c);
});
I think this is what you are looking for.

HTML canvas fill difference on Firefox vs Chrome

Consider the snippet below - available on jsFiddle: http://jsfiddle.net/Xqu5U/2/
ctx = document.getElementById('canvas').getContext('2d');
ctx.beginPath();
ctx.fillStyle = '#FF0000';
for (var i = 0; i < 20; i++) {
ctx.arc(i * 10, 50 + Math.sin(i * 0.5) * 15, 2, 0, Math.PI * 2);
}
ctx.fill();
It works as expected on Google Chrome, but Firefox renders a fill from the last arc to the first one.
How can the snippet above be updated to get Firefox drawing the arcs exactly like Chrome?
I found a way to get it working: http://jsfiddle.net/Xqu5U/3/.
Basically just add ctx.closePath() inside the for loop. Not sure if this is the best solution though...
I know this is old question but for the future reference:
ctx = document.getElementById('canvas').getContext('2d');
ctx.beginPath()
ctx.fillStyle = '#FF0000'
for (var i = 0; i < 20; i++) {
ctx.arc(i * 10, 50 + Math.sin(i * 0.5) * 15, 2, 0, Math.PI * 2)
ctx.closePath()
}
ctx.fill()
It's really old, but someone just pointed me to here.
The problem was a chrome bug (now fixed since an undetermined long time). FF behavior was correct.
arc() method doesn't include a moveTo(x, y) call, but a lineTo one.
So in order to get your desired result, you just have to call ctx.moveTo(nextCX + radius, nextCY) where nextCX and nextCY are the center x and y coordinates of your next arc to be drawn. We add radius to the x position because, when the arc's starting angle is set to 0, the arc is being drawn from 3 o'clock, without this + radius, we would still have an internal lineTo(cx + radius, cy) being added, visible when calling stroke().
var ctx = document.getElementById('canvas').getContext('2d');
ctx.beginPath();
ctx.fillStyle = '#FF0000';
for (var i = 0; i < 20; i++) {
// you need to moveTo manually.
ctx.moveTo(i * 10 + 2, 50 + Math.sin(i * 0.5) * 15)
ctx.arc(i * 10, 50 + Math.sin(i * 0.5) * 15, 2, 0, Math.PI * 2);
}
ctx.fill();
<canvas id="canvas"></canvas>
You don't have really something to do about it...
It's the way both browser's work...
You can always design it with CSS with the right commands to make it the same...
Go to http://w3schools.com and find what you need for doing that :)
Good luck !

How to draw a rounded rectangle using HTML Canvas?

HTML Canvas provides methods for drawing rectangles, fillRect() and strokeRect(), but I can't find a method for making rectangles with rounded corners. How can I do that?
Nowadays you can just use context.roundRect. See further details on Kaiido's answer
var ctx = document.getElementById("rounded-rect").getContext("2d");
ctx.beginPath();
// Draw using 5px for border radius on all sides
// stroke it but no fill
ctx.roundRect(5, 5, 50, 50, 5);
ctx.stroke();
// To change the color on the rectangle, just manipulate the context
ctx.strokeStyle = "rgb(255, 0, 0)";
ctx.fillStyle = "rgba(255, 255, 0, .5)";
ctx.beginPath();
ctx.roundRect(100, 5, 100, 100, 20);
ctx.stroke();
ctx.fill();
// Manipulate it again
ctx.strokeStyle = "#0f0";
ctx.fillStyle = "#ddd";
// Different radii for each corner, top-left clockwise to bottom-left
ctx.beginPath();
ctx.roundRect(300, 5, 200, 100, [50,0,25,0]);
ctx.fill();
ctx.stroke();
<canvas id="rounded-rect" width="500" height="200">
<!-- Insert fallback content here -->
</canvas>
Old answer:
I needed to do the same thing and created a method to do it.
/**
* Draws a rounded rectangle using the current state of the canvas.
* If you omit the last three params, it will draw a rectangle
* outline with a 5 pixel border radius
* #param {CanvasRenderingContext2D} ctx
* #param {Number} x The top left x coordinate
* #param {Number} y The top left y coordinate
* #param {Number} width The width of the rectangle
* #param {Number} height The height of the rectangle
* #param {Number} [radius = 5] The corner radius; It can also be an object
* to specify different radii for corners
* #param {Number} [radius.tl = 0] Top left
* #param {Number} [radius.tr = 0] Top right
* #param {Number} [radius.br = 0] Bottom right
* #param {Number} [radius.bl = 0] Bottom left
* #param {Boolean} [fill = false] Whether to fill the rectangle.
* #param {Boolean} [stroke = true] Whether to stroke the rectangle.
*/
function roundRect(
ctx,
x,
y,
width,
height,
radius = 5,
fill = false,
stroke = true
) {
if (typeof radius === 'number') {
radius = {tl: radius, tr: radius, br: radius, bl: radius};
} else {
radius = {...{tl: 0, tr: 0, br: 0, bl: 0}, ...radius};
}
ctx.beginPath();
ctx.moveTo(x + radius.tl, y);
ctx.lineTo(x + width - radius.tr, y);
ctx.quadraticCurveTo(x + width, y, x + width, y + radius.tr);
ctx.lineTo(x + width, y + height - radius.br);
ctx.quadraticCurveTo(x + width, y + height, x + width - radius.br, y + height);
ctx.lineTo(x + radius.bl, y + height);
ctx.quadraticCurveTo(x, y + height, x, y + height - radius.bl);
ctx.lineTo(x, y + radius.tl);
ctx.quadraticCurveTo(x, y, x + radius.tl, y);
ctx.closePath();
if (fill) {
ctx.fill();
}
if (stroke) {
ctx.stroke();
}
}
// Now you can just call
var ctx = document.getElementById("rounded-rect").getContext("2d");
// Draw using default border radius,
// stroke it but no fill (function's default values)
roundRect(ctx, 5, 5, 50, 50);
// To change the color on the rectangle, just manipulate the context
ctx.strokeStyle = "rgb(255, 0, 0)";
ctx.fillStyle = "rgba(255, 255, 0, .5)";
roundRect(ctx, 100, 5, 100, 100, 20, true);
// Manipulate it again
ctx.strokeStyle = "#0f0";
ctx.fillStyle = "#ddd";
// Different radii for each corner, others default to 0
roundRect(ctx, 300, 5, 200, 100, {
tl: 50,
br: 25
}, true);
<canvas id="rounded-rect" width="500" height="200">
<!-- Insert fallback content here -->
</canvas>
Different radii per corner provided by Corgalore
See http://js-bits.blogspot.com/2010/07/canvas-rounded-corner-rectangles.html
for further explanation
I started with #jhoff's solution, but rewrote it to use width/height parameters, and using arcTo makes it quite a bit more terse:
CanvasRenderingContext2D.prototype.roundRect = function (x, y, w, h, r) {
if (w < 2 * r) r = w / 2;
if (h < 2 * r) r = h / 2;
this.beginPath();
this.moveTo(x+r, y);
this.arcTo(x+w, y, x+w, y+h, r);
this.arcTo(x+w, y+h, x, y+h, r);
this.arcTo(x, y+h, x, y, r);
this.arcTo(x, y, x+w, y, r);
this.closePath();
return this;
}
Also returning the context so you can chain a little. E.g.:
ctx.roundRect(35, 10, 225, 110, 20).stroke(); //or .fill() for a filled rect
The HTML5 canvas doesn't provide a method to draw a rectangle with rounded corners.
How about using the lineTo() and arc() methods?
You can also use the quadraticCurveTo() method instead of the arc() method.
Juan, I made a slight improvement to your method to allow for changing each rectangle corner radius individually:
/**
* Draws a rounded rectangle using the current state of the canvas.
* If you omit the last three params, it will draw a rectangle
* outline with a 5 pixel border radius
* #param {Number} x The top left x coordinate
* #param {Number} y The top left y coordinate
* #param {Number} width The width of the rectangle
* #param {Number} height The height of the rectangle
* #param {Object} radius All corner radii. Defaults to 0,0,0,0;
* #param {Boolean} fill Whether to fill the rectangle. Defaults to false.
* #param {Boolean} stroke Whether to stroke the rectangle. Defaults to true.
*/
CanvasRenderingContext2D.prototype.roundRect = function (x, y, width, height, radius, fill, stroke) {
var cornerRadius = { upperLeft: 0, upperRight: 0, lowerLeft: 0, lowerRight: 0 };
if (typeof stroke == "undefined") {
stroke = true;
}
if (typeof radius === "object") {
for (var side in radius) {
cornerRadius[side] = radius[side];
}
}
this.beginPath();
this.moveTo(x + cornerRadius.upperLeft, y);
this.lineTo(x + width - cornerRadius.upperRight, y);
this.quadraticCurveTo(x + width, y, x + width, y + cornerRadius.upperRight);
this.lineTo(x + width, y + height - cornerRadius.lowerRight);
this.quadraticCurveTo(x + width, y + height, x + width - cornerRadius.lowerRight, y + height);
this.lineTo(x + cornerRadius.lowerLeft, y + height);
this.quadraticCurveTo(x, y + height, x, y + height - cornerRadius.lowerLeft);
this.lineTo(x, y + cornerRadius.upperLeft);
this.quadraticCurveTo(x, y, x + cornerRadius.upperLeft, y);
this.closePath();
if (stroke) {
this.stroke();
}
if (fill) {
this.fill();
}
}
Use it like this:
var canvas = document.getElementById("canvas");
var c = canvas.getContext("2d");
c.fillStyle = "blue";
c.roundRect(50, 100, 50, 100, {upperLeft:10,upperRight:10}, true, true);
Good news everyone!
roundRect(x, y, width, height, radii); is now officially part of the Canvas 2D API.
It is exposed on CanvasRenderingContext2D, Path2D and OffscreenCanvasRenderingContext2D objects.
Its radii parameter is an Array which contains either
a single float, representing the radius to use for all four corners,
two floats, for the top-left + bottom-right and top-right + bottom-left corners respectively,
three floats, for the top-left, top-right + bottom-left and bottom-right respectively,
or four floats, one per corner,
OR the same combinations, but with a DOMPointInit object, representing the x-radius and y-radius of each corner.
Currently, only Chrome has an implementation available, but you can find a polyfill I made, in this repo.
const canvas = document.querySelector("canvas");
const ctx = canvas.getContext("2d");
ctx.roundRect(20,20,80,80,[new DOMPoint(60,80), new DOMPoint(110,100)]);
ctx.strokeStyle = "green";
ctx.stroke();
const path = new Path2D();
path.roundRect(120,30,60,90,[0,25,new DOMPoint(60,80), new DOMPoint(110,100)]);
ctx.fillStyle = "purple";
ctx.fill(path);
// and a simple one
ctx.beginPath();
ctx.roundRect(200,20,80,80,[10]);
ctx.fillStyle = "orange";
ctx.fill();
<script src="https://cdn.jsdelivr.net/gh/Kaiido/roundRect#main/roundRect.js"></script>
<canvas></canvas>
This code creates a 100-pixel square, with rounded corners of 30 pixels.
var canvas = document.createElement("canvas");
document.body.appendChild(canvas);
var ctx = canvas.getContext("2d");
ctx.beginPath();
ctx.moveTo(100,100);
ctx.arcTo(0,100,0,0,30);
ctx.arcTo(0,0,100,0,30);
ctx.arcTo(100,0,100,100,30);
ctx.arcTo(100,100,0,100,30);
ctx.fill();
The drawPolygon function below can be used to draw any polygon with rounded corners.
See it running here.
function drawPolygon(ctx, pts, radius) {
if (radius > 0) {
pts = getRoundedPoints(pts, radius);
}
var i, pt, len = pts.length;
ctx.beginPath();
for (i = 0; i < len; i++) {
pt = pts[i];
if (i == 0) {
ctx.moveTo(pt[0], pt[1]);
} else {
ctx.lineTo(pt[0], pt[1]);
}
if (radius > 0) {
ctx.quadraticCurveTo(pt[2], pt[3], pt[4], pt[5]);
}
}
ctx.closePath();
}
function getRoundedPoints(pts, radius) {
var i1, i2, i3, p1, p2, p3, prevPt, nextPt,
len = pts.length,
res = new Array(len);
for (i2 = 0; i2 < len; i2++) {
i1 = i2-1;
i3 = i2+1;
if (i1 < 0) {
i1 = len - 1;
}
if (i3 == len) {
i3 = 0;
}
p1 = pts[i1];
p2 = pts[i2];
p3 = pts[i3];
prevPt = getRoundedPoint(p1[0], p1[1], p2[0], p2[1], radius, false);
nextPt = getRoundedPoint(p2[0], p2[1], p3[0], p3[1], radius, true);
res[i2] = [prevPt[0], prevPt[1], p2[0], p2[1], nextPt[0], nextPt[1]];
}
return res;
};
function getRoundedPoint(x1, y1, x2, y2, radius, first) {
var total = Math.sqrt(Math.pow(x2 - x1, 2) + Math.pow(y2 - y1, 2)),
idx = first ? radius / total : (total - radius) / total;
return [x1 + (idx * (x2 - x1)), y1 + (idx * (y2 - y1))];
};
The function receives an array with the polygon points, like this:
var canvas = document.getElementById("cv");
var ctx = canvas.getContext("2d");
ctx.strokeStyle = "#000000";
ctx.lineWidth = 5;
drawPolygon(ctx, [[20, 20],
[120, 20],
[120, 120],
[ 20, 120]], 10);
ctx.stroke();
This is a port and a more generic version of a solution posted here.
Here's one I wrote... uses arcs instead of quadratic curves for better control over radius. Also, it leaves the stroking and filling up to you
/* Canvas 2d context - roundRect
*
* Accepts 5 parameters:
the start_x,
start_y points,
the end_x,
end_y points,
the radius of the corners
*
* No return value
*/
CanvasRenderingContext2D.prototype.roundRect = function(sx,sy,ex,ey,r) {
var r2d = Math.PI/180;
if( ( ex - sx ) - ( 2 * r ) < 0 ) { r = ( ( ex - sx ) / 2 ); } //ensure that the radius isn't too large for x
if( ( ey - sy ) - ( 2 * r ) < 0 ) { r = ( ( ey - sy ) / 2 ); } //ensure that the radius isn't too large for y
this.beginPath();
this.moveTo(sx+r,sy);
this.lineTo(ex-r,sy);
this.arc(ex-r,sy+r,r,r2d*270,r2d*360,false);
this.lineTo(ex,ey-r);
this.arc(ex-r,ey-r,r,r2d*0,r2d*90,false);
this.lineTo(sx+r,ey);
this.arc(sx+r,ey-r,r,r2d*90,r2d*180,false);
this.lineTo(sx,sy+r);
this.arc(sx+r,sy+r,r,r2d*180,r2d*270,false);
this.closePath();
}
Here is an example:
var _e = document.getElementById('#my_canvas');
var _cxt = _e.getContext("2d");
_cxt.roundRect(35,10,260,120,20);
_cxt.strokeStyle = "#000";
_cxt.stroke();
So this is based out of using lineJoin="round" and with the proper proportions, mathematics and logic I have been able to make this function, this is not perfect but hope it helps. If you want to make each corner have a different radius take a look at: https://p5js.org/reference/#/p5/rect
Here ya go:
CanvasRenderingContext2D.prototype.roundRect = function (x,y,width,height,radius) {
radius = Math.min(Math.max(width-1,1),Math.max(height-1,1),radius);
var rectX = x;
var rectY = y;
var rectWidth = width;
var rectHeight = height;
var cornerRadius = radius;
this.lineJoin = "round";
this.lineWidth = cornerRadius;
this.strokeRect(rectX+(cornerRadius/2), rectY+(cornerRadius/2), rectWidth-cornerRadius, rectHeight-cornerRadius);
this.fillRect(rectX+(cornerRadius/2), rectY+(cornerRadius/2), rectWidth-cornerRadius, rectHeight-cornerRadius);
this.stroke();
this.fill();
}
CanvasRenderingContext2D.prototype.roundRect = function (x,y,width,height,radius) {
radius = Math.min(Math.max(width-1,1),Math.max(height-1,1),radius);
var rectX = x;
var rectY = y;
var rectWidth = width;
var rectHeight = height;
var cornerRadius = radius;
this.lineJoin = "round";
this.lineWidth = cornerRadius;
this.strokeRect(rectX+(cornerRadius/2), rectY+(cornerRadius/2), rectWidth-cornerRadius, rectHeight-cornerRadius);
this.fillRect(rectX+(cornerRadius/2), rectY+(cornerRadius/2), rectWidth-cornerRadius, rectHeight-cornerRadius);
this.stroke();
this.fill();
}
var canvas = document.getElementById("myCanvas");
var ctx = canvas.getContext('2d');
function yop() {
ctx.clearRect(0,0,1000,1000)
ctx.fillStyle = "#ff0000";
ctx.strokeStyle = "#ff0000"; ctx.roundRect(Number(document.getElementById("myRange1").value),Number(document.getElementById("myRange2").value),Number(document.getElementById("myRange3").value),Number(document.getElementById("myRange4").value),Number(document.getElementById("myRange5").value));
requestAnimationFrame(yop);
}
requestAnimationFrame(yop);
<input type="range" min="0" max="1000" value="10" class="slider" id="myRange1"><input type="range" min="0" max="1000" value="10" class="slider" id="myRange2"><input type="range" min="0" max="1000" value="200" class="slider" id="myRange3"><input type="range" min="0" max="1000" value="100" class="slider" id="myRange4"><input type="range" min="1" max="1000" value="50" class="slider" id="myRange5">
<canvas id="myCanvas" width="1000" height="1000">
</canvas>
Here's a solution using the lineJoin property to round the corners. It works if you just need a solid shape, but not so much if you need a thin border that's smaller than the border radius.
function roundedRect(ctx, options) {
ctx.strokeStyle = options.color;
ctx.fillStyle = options.color;
ctx.lineJoin = "round";
ctx.lineWidth = options.radius;
ctx.strokeRect(
options.x+(options.radius*.5),
options.y+(options.radius*.5),
options.width-options.radius,
options.height-options.radius
);
ctx.fillRect(
options.x+(options.radius*.5),
options.y+(options.radius*.5),
options.width-options.radius,
options.height-options.radius
);
ctx.stroke();
ctx.fill();
}
const canvas = document.getElementsByTagName("canvas")[0];
const ctx = canvas.getContext("2d");
roundedRect(ctx, {
x: 10,
y: 10,
width: 200,
height: 100,
radius: 35,
color: "red"
});
<canvas></canvas>
Opera, ffs.
if (window["CanvasRenderingContext2D"]) {
/** #expose */
CanvasRenderingContext2D.prototype.roundRect = function(x, y, w, h, r) {
if (w < 2*r) r = w/2;
if (h < 2*r) r = h/2;
this.beginPath();
if (r < 1) {
this.rect(x, y, w, h);
} else {
if (window["opera"]) {
this.moveTo(x+r, y);
this.arcTo(x+r, y, x, y+r, r);
this.lineTo(x, y+h-r);
this.arcTo(x, y+h-r, x+r, y+h, r);
this.lineTo(x+w-r, y+h);
this.arcTo(x+w-r, y+h, x+w, y+h-r, r);
this.lineTo(x+w, y+r);
this.arcTo(x+w, y+r, x+w-r, y, r);
} else {
this.moveTo(x+r, y);
this.arcTo(x+w, y, x+w, y+h, r);
this.arcTo(x+w, y+h, x, y+h, r);
this.arcTo(x, y+h, x, y, r);
this.arcTo(x, y, x+w, y, r);
}
}
this.closePath();
};
/** #expose */
CanvasRenderingContext2D.prototype.fillRoundRect = function(x, y, w, h, r) {
this.roundRect(x, y, w, h, r);
this.fill();
};
/** #expose */
CanvasRenderingContext2D.prototype.strokeRoundRect = function(x, y, w, h, r) {
this.roundRect(x, y, w, h, r);
this.stroke();
};
}
Since Opera is going WebKit, this should also remain valid in the legacy case.
To make the function more consistent with the normal means of using a canvas context, the canvas context class can be extended to include a 'fillRoundedRect' method -- that can be called in the same way fillRect is called:
var canv = document.createElement("canvas");
var cctx = canv.getContext("2d");
// If thie canvasContext class doesn't have a fillRoundedRect, extend it now
if (!cctx.constructor.prototype.fillRoundedRect) {
// Extend the canvaseContext class with a fillRoundedRect method
cctx.constructor.prototype.fillRoundedRect =
function (xx,yy, ww,hh, rad, fill, stroke) {
if (typeof(rad) == "undefined") rad = 5;
this.beginPath();
this.moveTo(xx+rad, yy);
this.arcTo(xx+ww, yy, xx+ww, yy+hh, rad);
this.arcTo(xx+ww, yy+hh, xx, yy+hh, rad);
this.arcTo(xx, yy+hh, xx, yy, rad);
this.arcTo(xx, yy, xx+ww, yy, rad);
if (stroke) this.stroke(); // Default to no stroke
if (fill || typeof(fill)=="undefined") this.fill(); // Default to fill
}; // end of fillRoundedRect method
}
The code checks to see if the prototype for the constructor for the canvas context object contains a 'fillRoundedRect' property and adds one -- the first time around. It is invoked in the same manner as the fillRect method:
ctx.fillStyle = "#eef"; ctx.strokeStyle = "#ddf";
// ctx.fillRect(10,10, 200,100);
ctx.fillRoundedRect(10,10, 200,100, 5);
The method uses the arcTo method as Grumdring did. In the method, this is a reference to the ctx object. The stroke argument defaults to false if undefined. The fill argument defaults to fill the rectangle if undefined.
(Tested on Firefox, I don't know if all implementations permit extension in this manner.)
Method 1: Using path-drawing methods
The most straightforward method of doing this with HTML Canvas is by using the path-drawing methods of ctx:
const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
function roundedRect(ctx, x, y, width, height, radius) {
ctx.beginPath();
ctx.moveTo(x + radius, y);
ctx.lineTo(x + width - radius, y);
ctx.quadraticCurveTo(x + width, y, x + width, y + radius);
ctx.lineTo(x + width, y + height - radius);
ctx.quadraticCurveTo(x + width, y + height, x + width - radius, y + height);
ctx.lineTo(x + radius, y + height);
ctx.quadraticCurveTo(x, y + height, x, y + height - radius);
ctx.lineTo(x, y + radius);
ctx.quadraticCurveTo(x, y, x + radius, y);
ctx.closePath();
}
ctx.fillStyle = "red";
roundedRect(ctx, 10, 10, 100, 100, 20);
ctx.fill();
<canvas id="canvas">
<!-- Fallback content -->
</canvas>
Method 2: Using Path2D
You can also draw rounded rectangles in HTML Canvas by using the Path2D interface:
Example 1
const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
function roundedRect(x, y, width, height, radius) {
return new Path2D(`M ${x + radius} ${y} H ${x + width - radius} a ${radius} ${radius} 0 0 1 ${radius} ${radius} V ${y + height - radius} a ${radius} ${radius} 0 0 1 ${-radius} ${radius} H ${x + radius} a ${radius} ${radius} 0 0 1 ${-radius} ${-radius} V ${y + radius} a ${radius} ${radius} 0 0 1 ${radius} ${-radius}`);
}
ctx.fillStyle = "blue";
ctx.fill(roundedRect(10, 10, 100, 100, 20));
<canvas id="canvas">
<!-- Fallback content -->
</canvas>
Example 2
const canvas = document.getElementById("canvas");
const ctx = canvas.getContext("2d");
function roundedRect(x, y, width, height, radius) {
let path = new Path2D();
path.moveTo(x + radius, y);
path.lineTo(x + width - radius, y);
path.quadraticCurveTo(x + width, y, x + width, y + radius);
path.lineTo(x + width, y + height - radius);
path.quadraticCurveTo(x + width, y + height, x + width - radius, y + height);
path.lineTo(x + radius, y + height);
path.quadraticCurveTo(x, y + height, x, y + height - radius);
path.lineTo(x, y + radius);
path.quadraticCurveTo(x, y, x + radius, y);
path.closePath();
return path;
}
ctx.fillStyle = "green";
ctx.fill(roundedRect(10, 10, 100, 100, 20));
<canvas id="canvas">
<!-- Fallback content -->
</canvas>
try to add this line , when you want to get rounded corners : ctx.lineCap = "round";
NONE of the other answers can handle the following 3 cases correctly:
if ((width >= radius x 2) && (height <= radius * 2))
if ((width <= radius x 2) && (height >= radius * 2))
if ((width <= radius x 2) && (height <= radius * 2))
If any of these cases happen, you will not get a correctly drawn rectangle
My Solution handles ANY radius and ANY Width and Height dynamically, and should be the default answer
function roundRect(ctx, x, y, width, height, radius) {
/*
* Draws a rounded rectangle using the current state of the canvas.
*/
let w = width;
let h = height;
let r = radius;
ctx.stroke()
ctx.fill()
ctx.beginPath();
// Configure the roundedness of the rectangles corners
if ((w >= r * 2) && (h >= r * 2)) {
// Handles width and height larger than diameter
// Keep radius fixed
ctx.moveTo(x + r, y); // tr start
ctx.lineTo(x + w - r, y); // tr
ctx.quadraticCurveTo(x + w, y, x + w, y + r); //tr
ctx.lineTo(x + w, y + h - r); // br
ctx.quadraticCurveTo(x + w, y + h, x + w - r, y + h); // br
ctx.lineTo(x + r, y + h); // bl
ctx.quadraticCurveTo(x, y + h, x, y + h - r); // bl
ctx.lineTo(x, y + r); // tl
ctx.quadraticCurveTo(x, y, x + r, y); // tl
} else if ((w < r * 2) && (h > r * 2)) {
// Handles width lower than diameter
// Radius must dynamically change as half of width
r = w / 2;
ctx.moveTo(x + w, y + h - r); // br start
ctx.quadraticCurveTo(x + w, y + h, x + w - r, y + h); // br curve
ctx.quadraticCurveTo(x, y + h, x, y + h - r) // bl curve
ctx.lineTo(x, y + r); // line
ctx.quadraticCurveTo(x, y, x + r, y); // tl
ctx.quadraticCurveTo(x + w, y, x + w, y + r); // tl
ctx.lineTo(x + w, y + h - r); // line
} else if ((w > r * 2) && (h < r * 2)) {
// Handles height lower than diameter
// Radius must dynamically change as half of height
r = h / 2;
ctx.moveTo(x + w - r, y + h); // br start
ctx.quadraticCurveTo(x + w, y + h, x + w, y + r); // br curve
ctx.quadraticCurveTo(x + w, y, x + w - r, y); // tr curve
ctx.lineTo(x + r, y); // line between tr tl
ctx.quadraticCurveTo(x, y, x, y + r); // tl curve
ctx.quadraticCurveTo(x, y + h, x + r, y + h); // bl curve
} else if ((w < 2 * r) && (h < 2 * r)) {
// Handles width and height lower than diameter
ctx.moveTo(x + w / 2, y + h);
ctx.quadraticCurveTo(x + w, y + h, x + w, y + h / 2); // bl curve
ctx.quadraticCurveTo(x + w, y, x + w / 2, y); // tr curve
ctx.quadraticCurveTo(x, y, x, y + h / 2); // tl curve
ctx.quadraticCurveTo(x, y + h, x + w / 2, y + h); // bl curve
}
ctx.closePath();
}