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pixdisp
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Add primitives drawLine, drawRect, drawRectFilled, drawCircle

This commit is contained in:
Martijn de Boer 2018-01-04 02:36:13 +01:00
parent 5fbc7a183c
commit 52ddfdbad5
1 changed files with 95 additions and 8 deletions
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103
drivers/driver.js
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@ -67,21 +67,108 @@ class Driver {
* Set pixel color
*/
setPixel( x, y, r = 0, g = 0, b = 0, a = 1 ) {
this.matrix[x][y].r = r;
this.matrix[x][y].g = g;
this.matrix[x][y].b = b;
this.matrix[x][y].a = a;
if ( x >= 0 && x <= this.width &&
y >= 0 && y <= this.height ) {
this.matrix[x][y].r = r;
this.matrix[x][y].g = g;
this.matrix[x][y].b = b;
this.matrix[x][y].a = a;
}
}
/**
* Return the pixel color
*/
getPixel( x, y ) {
if ( x >= 0 && x <= this.width &&
y >= 0 && y <= this.height ) {
return {
r: this.matrix[x][y].r,
g: this.matrix[x][y].g,
b: this.matrix[x][y].b,
a: this.matrix[x][y].a
}
}
return {
r: this.matrix[x][y].r,
g: this.matrix[x][y].g,
b: this.matrix[x][y].b,
a: this.matrix[x][y].a
r: -1,
g: -1,
b: -1,
a: -1
}
}
/**
* Draw a line from x1,y1 to x2,y2
*/
drawLine( x1, y1, x2, y2, r = 0, g = 0, b = 0, a = 1 ) {
let dx = x2 - x1;
let dy = y2 - y1;
for ( let x = x1; x <= x2; x++ ) {
let y = Math.floor( y1 + dy * ( x - x1 ) / dx );
this.setPixel( x, y, r, g, b, a );
}
}
/**
* Draw a rectangle from x,y with dimensions w,h
*/
drawRect( x1, y1, w, h, r = 0, g = 0, b = 0, a = 1 ) {
for ( let x = x1; x < x1 + w; x++ ) {
this.setPixel( x, y1, r, g, b, a );
this.setPixel( x, y1 + h - 1, r, g, b, a );
}
for ( let y = y1; y < y1 + h - 1; y++ ) {
this.setPixel( x1, y, r, g, b, a );
this.setPixel( x1 + w - 1, y, r, g, b, a );
}
}
/**
* Draw a rectangle from x,y with dimensions w,h
*/
drawRectFilled( x1, y1, w, h, r = 0, g = 0, b = 0, a = 1 ) {
for ( let x = x1; x < x1 + w; x++ ) {
for ( let y = y1; y < y1 + h; y++ ) {
this.setPixel( x, y, r, g, b, a );
}
}
}
/**
* Draws a circle at x,y with radius r
*/
drawCircle( x1, y1, radius, r = 0, g = 0, b = 0, a = 1 ) {
let x = radius - 1;
let y = 0;
let dx = 1;
let dy = 1;
let err = dx - ( radius << 1 );
while ( x >= y ) {
this.setPixel( x1 + x, y1 + y, r, g, b, a );
this.setPixel( x1 + y, y1 + x, r, g, b, a );
this.setPixel( x1 - y, y1 + x, r, g, b, a );
this.setPixel( x1 - x, y1 + y, r, g, b, a );
this.setPixel( x1 - x, y1 - y, r, g, b, a );
this.setPixel( x1 - y, y1 - x, r, g, b, a );
this.setPixel( x1 + y, y1 - x, r, g, b, a );
this.setPixel( x1 + x, y1 - y, r, g, b, a );
if ( err <= 0 ) {
y++;
err += dy;
dy += 2;
}
if ( err > 0 ) {
x--;
dx += 2;
err += dx - ( radius << 1 );
}
}
}