added support for silkscreen text (#27)

* added support for silkscreen text

* cleanup

package.json

@@ -34,6 +34,7 @@
     "circuit-json": "*"
   },
   "dependencies": {
+    "@tscircuit/alphabet": "^0.0.2",
     "fast-json-stable-stringify": "^2.1.0"
   }
 }

src/gerber/convert-soup-to-gerber-commands/defineAperturesForLayer.ts

@@ -7,6 +7,7 @@ import type {
   PcbHole,
   PcbSolderPaste,
   PcbSilkscreenPath,
+  PcbSilkscreenText,
 } from "circuit-json"
 import stableStringify from "fast-json-stable-stringify"
 import type { AnyGerberCommand } from "../any_gerber_command"
@@ -116,6 +117,18 @@ export const getApertureConfigFromPcbSilkscreenPath = (
   throw new Error(`Provide stroke_width for: ${elm as any}`)
 }
 
+export const getApertureConfigFromPcbSilkscreenText = (
+  elm: PcbSilkscreenText,
+): ApertureTemplateConfig => {
+  if ("font_size" in elm) {
+    return {
+      standard_template_code: "C",
+      diameter: elm.font_size / 4, // font size and diamater have different units of measurement
+    }
+  }
+  throw new Error(`Provide font_size for: ${elm as any}`)
+}
+
 export const getApertureConfigFromPcbSolderPaste = (
   elm: PcbSolderPaste,
 ): ApertureTemplateConfig => {
@@ -242,6 +255,8 @@ function getAllApertureTemplateConfigsForLayer(
       addConfigIfNew(getApertureConfigFromPcbVia(elm))
     } else if (elm.type === "pcb_silkscreen_path")
       addConfigIfNew(getApertureConfigFromPcbSilkscreenPath(elm))
+    else if (elm.type === "pcb_silkscreen_text")
+      addConfigIfNew(getApertureConfigFromPcbSilkscreenText(elm))
   }
 
   return configs

src/gerber/convert-soup-to-gerber-commands/index.ts

@@ -8,13 +8,15 @@ import {
   getApertureConfigFromCirclePcbHole,
   getApertureConfigFromPcbPlatedHole,
   getApertureConfigFromPcbSilkscreenPath,
+  getApertureConfigFromPcbSilkscreenText,
   getApertureConfigFromPcbSmtpad,
   getApertureConfigFromPcbSolderPaste,
   getApertureConfigFromPcbVia,
 } from "./defineAperturesForLayer"
 import { findApertureNumber } from "./findApertureNumber"
 import { getCommandHeaders } from "./getCommandHeaders"
 import { getGerberLayerName } from "./getGerberLayerName"
+import { lineAlphabet } from "@tscircuit/alphabet"
 
 /**
  * Converts tscircuit soup to arrays of Gerber commands for each layer
@@ -146,6 +148,72 @@ export const convertSoupToGerberCommands = (
             })
           }
 
+          glayer.push(...gerber.build())
+        }
+      } else if (element.type === "pcb_silkscreen_text") {
+        if (element.layer === layer) {
+          const glayer = glayers[getGerberLayerName(layer, "silkscreen")]
+          const apertureConfig = getApertureConfigFromPcbSilkscreenText(element)
+          const gerber = gerberBuilder().add("select_aperture", {
+            aperture_number: findApertureNumber(glayer, apertureConfig),
+          })
+
+          let initialX = element.anchor_position.x
+          let initialY = element.anchor_position.y
+          const fontSize = element.font_size
+          const letterSpacing = fontSize * 0.4
+          const spaceWidth = fontSize * 0.5
+
+          const textWidth =
+            element.text.split("").reduce((width, char) => {
+              if (char === " ") {
+                return width + spaceWidth + letterSpacing
+              }
+              return width + fontSize + letterSpacing
+            }, 0) - letterSpacing
+
+          const textHeight = fontSize
+          switch (element.anchor_alignment || "center") {
+            case "top_right":
+              // No adjustment needed
+              break
+            case "top_left":
+              initialX -= textWidth
+              break
+            case "bottom_right":
+              initialY -= textHeight
+              break
+            case "bottom_left":
+              initialX -= textWidth
+              initialY -= textHeight
+              break
+            case "center":
+              initialX -= textWidth / 2
+              initialY -= textHeight / 2
+              break
+          }
+
+          let anchoredX = initialX
+          const anchoredY = initialY
+          for (const char of element.text.toUpperCase()) {
+            if (char === " ") {
+              anchoredX += spaceWidth + letterSpacing
+              continue
+            }
+
+            const letterPaths = lineAlphabet[char] || []
+            for (const path of letterPaths) {
+              const x1 = anchoredX + path.x1 * fontSize
+              const y1 = anchoredY + path.y1 * fontSize
+              const x2 = anchoredX + path.x2 * fontSize
+              const y2 = anchoredY + path.y2 * fontSize
+
+              gerber.add("move_operation", { x: x1, y: mfy(y1) })
+              gerber.add("plot_operation", { x: x2, y: mfy(y2) })
+            }
+
+            anchoredX += fontSize + letterSpacing // Move to next character position
+          }
           glayer.push(...gerber.build())
         }
       } else if (element.type === "pcb_smtpad") {

tests/gerber/generate-board-with-slikscreen-text.test.tsx

@@ -0,0 +1,121 @@
+import { test, expect } from "bun:test"
+import { convertSoupToGerberCommands } from "src/gerber/convert-soup-to-gerber-commands"
+import {
+  stringifyGerberCommandLayers,
+  stringifyGerberCommands,
+} from "src/gerber/stringify-gerber"
+import { maybeOutputGerber } from "tests/fixtures/maybe-output-gerber"
+import gerberToSvg from "gerber-to-svg"
+import type { AnyCircuitElement } from "circuit-json"
+import {
+  convertSoupToExcellonDrillCommands,
+  stringifyExcellonDrill,
+} from "src/excellon-drill"
+import { Circuit } from "@tscircuit/core"
+
+test("Generate simple board with a multi-layer trace", async () => {
+  const circuit = new Circuit()
+  circuit.add(
+    <board
+      width={160}
+      height={40}
+      outline={[
+        { x: -80, y: -5 },
+        { x: -80, y: 20 },
+        { x: 30, y: 20 },
+        { x: 30, y: -20 },
+        { x: 20, y: -5 },
+      ]}
+    >
+      <platedhole
+        name="H1"
+        shape="circle"
+        holeDiameter={1}
+        outerDiameter={2}
+        pcbX={27}
+        pcbY={-12}
+      />
+      <hole name="H1" diameter={0.2} pcbX={-30} pcbY={15} />
+      <hole name="H1" diameter={0.2} pcbX={-30} pcbY={12} />
+
+      <silkscreentext
+        text="large gerber text**"
+        fontSize={4}
+        layer={"top"}
+        pcbX={-20}
+        pcbY={0}
+      />
+      <silkscreentext
+        text="medium gerber text."
+        fontSize={2}
+        layer={"top"}
+        pcbX={-30}
+        pcbY={5}
+      />
+      <silkscreentext
+        text="small gerber text"
+        fontSize={1}
+        layer={"top"}
+        pcbX={-30}
+        pcbY={10}
+      />
+      <silkscreentext
+        text="][[]][><][[]]["
+        fontSize={0.5}
+        anchorAlignment="center"
+        layer={"top"}
+        pcbX={-30}
+        pcbY={12}
+      />
+      <silkscreentext
+        text="bottom left[]"
+        fontSize={0.5}
+        anchorAlignment="bottom_left"
+        layer={"top"}
+        pcbX={-30}
+        pcbY={15}
+      />
+      <silkscreentext
+        text="[]bottom right"
+        fontSize={0.5}
+        anchorAlignment="bottom_right"
+        layer={"top"}
+        pcbX={-30}
+        pcbY={15}
+      />
+      <silkscreentext
+        text="top left[]"
+        fontSize={0.5}
+        anchorAlignment="top_left"
+        layer={"top"}
+        pcbX={-30}
+        pcbY={15}
+      />
+      <silkscreentext
+        text="[]top right"
+        fontSize={0.5}
+        anchorAlignment="top_right"
+        layer={"top"}
+        pcbX={-30}
+        pcbY={15}
+      />
+    </board>,
+  )
+  const soup = circuit.getCircuitJson()
+
+  const gerber_cmds = convertSoupToGerberCommands(soup)
+  const excellon_drill_cmds = convertSoupToExcellonDrillCommands({
+    circuitJson: soup,
+    is_plated: true,
+  })
+
+  const gerberOutput = stringifyGerberCommandLayers(gerber_cmds)
+  const excellonDrillOutput = stringifyExcellonDrill(excellon_drill_cmds)
+
+  await maybeOutputGerber(gerberOutput, excellonDrillOutput)
+
+  expect(gerberOutput).toMatchGerberSnapshot(
+    import.meta.path,
+    "silkscreen-text",
+  )
+})