gl renderer: proper block cursor, status screen,

special character rendering

js/term/font_cache.js

@@ -42,7 +42,7 @@ module.exports = class GLFontCache {
     ctx.textAlign = 'center'
     ctx.textBaseline = 'middle'
     ctx.fillStyle = 'white'
-    ctx.fillText(character, cellSize.width * 1.5, cellSize.height * 1.5)
+    this.drawCharacter(character)
 
     let imageData = ctx.getImageData(0, 0, width, height)
 
@@ -56,4 +56,146 @@ module.exports = class GLFontCache {
 
     return texture
   }
+
+  drawCharacter (character) {
+    const { ctx, cellSize } = this
+
+    let screenX = cellSize.width
+    let screenY = cellSize.height
+
+    let codePoint = character.codePointAt(0)
+    if (codePoint >= 0x2580 && codePoint <= 0x259F) {
+      // block elements
+      ctx.beginPath()
+      const left = screenX
+      const top = screenY
+      const cw = cellSize.width
+      const ch = cellSize.height
+      const c2w = cellSize.width / 2
+      const c2h = cellSize.height / 2
+
+      // http://www.fileformat.info/info/unicode/block/block_elements/utf8test.htm
+      //         0x00  0x01  0x02  0x03  0x04  0x05  0x06  0x07  0x08  0x09  0x0A  0x0B  0x0C  0x0D  0x0E  0x0F
+      // 0x2580     ▀     ▁     ▂     ▃     ▄     ▅     ▆     ▇     █     ▉     ▊     ▋     ▌     ▍     ▎     ▏
+      // 0x2590     ▐     ░     ▒     ▓     ▔     ▕     ▖     ▗     ▘     ▙     ▚     ▛     ▜     ▝     ▞     ▟
+
+      if (codePoint === 0x2580) {
+        // upper half block >▀<
+        ctx.rect(left, top, cw, c2h)
+      } else if (codePoint <= 0x2588) {
+        // lower n eighth block (increasing) >▁< to >█<
+        let offset = (1 - (codePoint - 0x2580) / 8) * ch
+        ctx.rect(left, top + offset, cw, ch - offset)
+      } else if (codePoint <= 0x258F) {
+        // left n eighth block (decreasing) >▉< to >▏<
+        let offset = (codePoint - 0x2588) / 8 * cw
+        ctx.rect(left, top, cw - offset, ch)
+      } else if (codePoint === 0x2590) {
+        // right half block >▐<
+        ctx.rect(left + c2w, top, c2w, ch)
+      } else if (codePoint <= 0x2593) {
+        // shading >░< >▒< >▓<
+
+        // dot spacing by dividing cell size by a constant. This could be
+        // reworked to always return a whole number, but that would require
+        // prime factorization, and doing that without a loop would let you
+        // take over the world, which is not within the scope of this project.
+        let dotSpacingX, dotSpacingY, dotSize
+        if (codePoint === 0x2591) {
+          dotSpacingX = cw / 4
+          dotSpacingY = ch / 10
+          dotSize = 1
+        } else if (codePoint === 0x2592) {
+          dotSpacingX = cw / 6
+          dotSpacingY = cw / 10
+          dotSize = 1
+        } else if (codePoint === 0x2593) {
+          dotSpacingX = cw / 4
+          dotSpacingY = cw / 7
+          dotSize = 2
+        }
+
+        let alignRight = false
+        for (let dy = 0; dy < ch; dy += dotSpacingY) {
+          for (let dx = 0; dx < cw; dx += dotSpacingX) {
+            // prevent overflow
+            let dotSizeY = Math.min(dotSize, ch - dy)
+            ctx.rect(left + (alignRight ? cw - dx - dotSize : dx), top + dy, dotSize, dotSizeY)
+          }
+          alignRight = !alignRight
+        }
+      } else if (codePoint === 0x2594) {
+        // upper one eighth block >▔<
+        ctx.rect(left, top, cw, ch / 8)
+      } else if (codePoint === 0x2595) {
+        // right one eighth block >▕<
+        ctx.rect(left + (7 / 8) * cw, top, cw / 8, ch)
+      } else if (codePoint === 0x2596) {
+        // left bottom quadrant >▖<
+        ctx.rect(left, top + c2h, c2w, c2h)
+      } else if (codePoint === 0x2597) {
+        // right bottom quadrant >▗<
+        ctx.rect(left + c2w, top + c2h, c2w, c2h)
+      } else if (codePoint === 0x2598) {
+        // left top quadrant >▘<
+        ctx.rect(left, top, c2w, c2h)
+      } else if (codePoint === 0x2599) {
+        // left chair >▙<
+        ctx.rect(left, top, c2w, ch)
+        ctx.rect(left + c2w, top + c2h, c2w, c2h)
+      } else if (codePoint === 0x259A) {
+        // quadrants lt rb >▚<
+        ctx.rect(left, top, c2w, c2h)
+        ctx.rect(left + c2w, top + c2h, c2w, c2h)
+      } else if (codePoint === 0x259B) {
+        // left chair upside down >▛<
+        ctx.rect(left, top, c2w, ch)
+        ctx.rect(left + c2w, top, c2w, c2h)
+      } else if (codePoint === 0x259C) {
+        // right chair upside down >▜<
+        ctx.rect(left, top, cw, c2h)
+        ctx.rect(left + c2w, top + c2h, c2w, c2h)
+      } else if (codePoint === 0x259D) {
+        // right top quadrant >▝<
+        ctx.rect(left + c2w, top, c2w, c2h)
+      } else if (codePoint === 0x259E) {
+        // quadrants lb rt >▞<
+        ctx.rect(left, top + c2h, c2w, c2h)
+        ctx.rect(left + c2w, top, c2w, c2h)
+      } else if (codePoint === 0x259F) {
+        // right chair upside down >▟<
+        ctx.rect(left, top + c2h, c2w, c2h)
+        ctx.rect(left + c2w, top, c2w, ch)
+      }
+
+      ctx.fill()
+    } else if (codePoint >= 0xE0B0 && codePoint <= 0xE0B3) {
+      // powerline symbols, except branch, line, and lock. Basically, just the triangles
+      ctx.beginPath()
+
+      if (codePoint === 0xE0B0 || codePoint === 0xE0B1) {
+        // right-pointing triangle
+        ctx.moveTo(screenX, screenY)
+        ctx.lineTo(screenX + cellSize.width, screenY + cellSize.height / 2)
+        ctx.lineTo(screenX, screenY + cellSize.height)
+      } else if (codePoint === 0xE0B2 || codePoint === 0xE0B3) {
+        // left-pointing triangle
+        ctx.moveTo(screenX + cellSize.width, screenY)
+        ctx.lineTo(screenX, screenY + cellSize.height / 2)
+        ctx.lineTo(screenX + cellSize.width, screenY + cellSize.height)
+      }
+
+      if (codePoint % 2 === 0) {
+        // triangle
+        ctx.fill()
+      } else {
+        // chevron
+        ctx.strokeStyle = ctx.fillStyle
+        ctx.stroke()
+      }
+    } else {
+      // Draw other characters using the text renderer
+      ctx.fillText(character, cellSize.width * 1.5, cellSize.height * 1.5)
+    }
+  }
 }

js/term/webgl_renderer.js

@@ -73,8 +73,10 @@ module.exports = class WebGLRenderer extends EventEmitter {
   }
 
   resetDrawn (width, height) {
-    this.gl.clearColor(0, 0, 0, 1)
+    this.gl.clearColor(...this.getColor(this.defaultBG))
-    this.gl.viewport(0, 0, width, height)
+    if (width && height) {
+      this.gl.viewport(0, 0, width, height)
+    }
     this.gl.enable(this.gl.BLEND)
     this.gl.blendFunc(this.gl.SRC_ALPHA, this.gl.ONE_MINUS_SRC_ALPHA)
   }
@@ -229,10 +231,16 @@ precision mediump float;
 attribute vec2 position;
 uniform mat4 projection;
 uniform vec2 char_pos;
+uniform bool clip;
 varying highp vec2 tex_coord;
 void main() {
-  gl_Position = projection * vec4(char_pos - vec2(1.0, 1.0) + 3.0 * position, 0.0, 1.0);
+  if (clip) {
-  tex_coord = position;
+    gl_Position = projection * vec4(char_pos + position, 0.0, 1.0);
+    tex_coord = position / 3.0 + vec2(1.0 / 3.0, 1.0 / 3.0);
+  } else {
+    gl_Position = projection * vec4(char_pos - vec2(1.0, 1.0) + 3.0 * position, 0.0, 1.0);
+    tex_coord = position;
+  }
 }
     `, `
 precision highp float;
@@ -266,7 +274,8 @@ void main() {
         projection: gl.getUniformLocation(charShader, 'projection'),
         charPos: gl.getUniformLocation(charShader, 'char_pos'),
         color: gl.getUniformLocation(charShader, 'color'),
-        texture: gl.getUniformLocation(charShader, 'texture')
+        texture: gl.getUniformLocation(charShader, 'texture'),
+        clip: gl.getUniformLocation(charShader, 'clip')
       }
     }
 
@@ -292,7 +301,32 @@ void main() {
   }
 
   draw (reason) {
-    const { gl, width, height, padding, devicePixelRatio } = this
+    const { gl, width, height, padding, devicePixelRatio, statusScreen } = this
+    let { screen, screenFG, screenBG, screenAttrs } = this
+
+    if (statusScreen) {
+      this.startDrawLoop()
+
+      screen = new Array(width * height).fill(' ')
+      screenFG = new Array(width * height).fill(this.defaultFG)
+      screenBG = new Array(width * height).fill(this.defaultBG)
+      screenAttrs = new Array(width * height).fill(ATTR_FG | ATTR_BG)
+
+      let text = statusScreen.title
+      for (let i = 0; i < Math.min(width * height, text.length); i++) {
+        screen[i] = text[i]
+      }
+      if (statusScreen.loading) {
+        let t = Date.now() / 1000
+
+        for (let i = width; i < Math.min(width * height, width + 8); i++) {
+          let offset = ((t * 12) - i) % 12
+          let value = Math.max(0.2, 1 - offset / 3) * 255
+          screenFG[i] = 256 + value + (value << 8) + (value << 16)
+          screen[i] = '*'
+        }
+      }
+    }
 
     if (this.debug && this._debug) this._debug.drawStart(reason)
 
@@ -323,12 +357,15 @@ void main() {
         this.cursor.y === y &&
         this.cursor.visible
 
-      let text = this.screen[cell]
+      let text = screen[cell]
-      let fg = this.screenFG[cell] | 0
+      let fg = screenFG[cell] | 0
-      let bg = this.screenBG[cell] | 0
+      let bg = screenBG[cell] | 0
-      let attrs = this.screenAttrs[cell] | 0
+      let attrs = screenAttrs[cell] | 0
       let inSelection = this.screenSelection[cell]
 
+      if (!(cell in screen)) continue
+      if (statusScreen) isCursor = false
+
       // let isDefaultBG = false
 
       if (!(attrs & ATTR_FG)) fg = this.defaultFG
@@ -351,9 +388,6 @@ void main() {
         bg = -2
       }
 
-      // TODO: actual cursor
-      if (isCursor) [fg, bg] = [bg, fg]
-
       gl.uniform2f(this.bgShader.uniforms.charPos, x, y)
       gl.uniform4f(this.bgShader.uniforms.color, ...this.getColor(bg))
 
@@ -369,7 +403,7 @@ void main() {
 
       this.drawSquare()
 
-      if (text.trim()) {
+      if (text.trim() || isCursor) {
         let fontIndex = 0
         if (attrs & ATTR_BOLD) fontIndex |= 1
         if (attrs & ATTR_ITALIC) fontIndex |= 2
@@ -377,7 +411,7 @@ void main() {
         let type = font + text
 
         if (!textCells[type]) textCells[type] = []
-        textCells[type].push({ x, y, text, font, fg })
+        textCells[type].push({ x, y, text, font, fg, bg, isCursor })
       }
     }
 
@@ -391,18 +425,54 @@ void main() {
       gl.uniform1i(this.charShader.uniforms.texture, 0)
 
       for (let cell of textCells[key]) {
-        let { x, y, fg } = cell
+        let { x, y, fg, bg, isCursor } = cell
 
         gl.uniform2f(this.charShader.uniforms.charPos, x, y)
         gl.uniform4f(this.charShader.uniforms.color, ...this.getColor(fg))
 
         this.drawSquare()
+
+        if (isCursor) {
+          if (fg === bg) {
+            fg = 7
+            bg = 0
+          }
+
+          this.useShader(this.bgShader, projection)
+          gl.uniform2f(this.bgShader.uniforms.extend, 0, 0)
+          gl.uniform2f(this.bgShader.uniforms.charPos, x, y)
+          gl.uniform4f(this.bgShader.uniforms.color, ...this.getColor(fg))
+          this.drawSquare()
+
+          this.useShader(this.charShader, projection)
+          gl.uniform4f(this.charShader.uniforms.color, ...this.getColor(bg))
+          gl.uniform1i(this.charShader.uniforms.clip, true)
+          this.drawSquare()
+          gl.uniform1i(this.charShader.uniforms.clip, false)
+        }
       }
     }
 
     if (this.debug && this._debug) this._debug.drawEnd()
   }
 
+  startDrawLoop () {
+    if (this._drawTimerThread) return
+    let threadID = Math.random().toString(36)
+    this._drawTimerThread = threadID
+    this.drawTimerLoop(threadID)
+  }
+
+  stopDrawLoop () {
+    this._drawTimerThread = null
+  }
+
+  drawTimerLoop (threadID) {
+    if (!threadID || threadID !== this._drawTimerThread) return
+    window.requestAnimationFrame(() => this.drawTimerLoop(threadID))
+    this.draw('draw-loop')
+  }
+
   static colorToRGBA (color) {
     color = color.substr(1)
     if (color.length === 3) {