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| 1 | +package me.rosuh.easywatermark.render |
| 2 | + |
| 3 | +import android.graphics.Bitmap |
| 4 | +import android.graphics.BitmapShader |
| 5 | +import android.graphics.Canvas |
| 6 | +import android.graphics.Color |
| 7 | +import android.graphics.Paint |
| 8 | +import android.graphics.Shader |
| 9 | +import android.text.Layout |
| 10 | +import android.text.StaticLayout |
| 11 | +import android.text.TextPaint |
| 12 | +import androidx.core.graphics.withSave |
| 13 | +import kotlinx.coroutines.withContext |
| 14 | +import me.rosuh.easywatermark.data.model.ImageInfo |
| 15 | +import me.rosuh.easywatermark.data.model.WaterMark |
| 16 | +import me.rosuh.easywatermark.ui.widget.utils.WaterMarkShader |
| 17 | +import kotlin.coroutines.CoroutineContext |
| 18 | +import kotlin.math.max |
| 19 | + |
| 20 | +/** |
| 21 | + * Android-only watermark renderer seam (CMP plan S2a). Centralizes the CURRENT preview/export |
| 22 | + * watermark logic that was duplicated across [me.rosuh.easywatermark.ui.widget.WaterMarkImageView] |
| 23 | + * (preview `onDraw` + companion cell builders) and |
| 24 | + * [me.rosuh.easywatermark.ui.MainViewModel] `generateImage` (export): |
| 25 | + * |
| 26 | + * - [buildTextShader] / [buildIconShader] — build one watermark cell + its tiling [BitmapShader] |
| 27 | + * (legacy Android `StaticLayout` / scaled-bitmap path; cell sizing via commonMain |
| 28 | + * [WatermarkGeometry]). |
| 29 | + * - [compose] — draw the cell shader over a target canvas: REPEAT tiles a region, CLAMP paints one |
| 30 | + * decal at a fractional offset. Preview and export now call the SAME helper. |
| 31 | + * |
| 32 | + * This is an EXTRACTION-ONLY slice: the bodies below are moved verbatim from the old call sites, so |
| 33 | + * rendered pixels are unchanged (guarded by the S0 strict export golden + the S2a composition |
| 34 | + * equivalence test). It is deliberately **Android-only** (it touches `android.graphics.*`, |
| 35 | + * `android.text.StaticLayout`, `TextPaint`) and therefore lives in `:app`, NOT `shared/commonMain` — |
| 36 | + * the platform-neutral renderer is a later, explicitly-approved migration slice. Likewise it keeps |
| 37 | + * the legacy text path and does NOT adopt `TextMeasurer`/`TextMeasureEnv` in this slice. |
| 38 | + */ |
| 39 | +object WatermarkRenderer { |
| 40 | + |
| 41 | + /** |
| 42 | + * Build the text watermark cell + REPEAT/CLAMP [BitmapShader]. Verbatim extraction of the former |
| 43 | + * `WaterMarkImageView.buildTextBitmapShader` (which now delegates here). Uses legacy |
| 44 | + * `StaticLayout` + the supplied [textPaint] (configured via `TextPaint.applyConfig`). |
| 45 | + */ |
| 46 | + suspend fun buildTextShader( |
| 47 | + imageInfo: ImageInfo, |
| 48 | + config: WaterMark, |
| 49 | + textPaint: TextPaint, |
| 50 | + coroutineContext: CoroutineContext, |
| 51 | + ): WaterMarkShader? = withContext(coroutineContext) { |
| 52 | + if (config.text.isBlank()) { |
| 53 | + return@withContext null |
| 54 | + } |
| 55 | + val showDebugRect = config.enableBounds |
| 56 | + var maxLineWidth = 0 |
| 57 | + val tileMode = config.obtainTileMode() |
| 58 | + // calculate the max width of all lines |
| 59 | + config.text.split("\n").forEach { |
| 60 | + val startIndex = config.text.indexOf(it).coerceAtLeast(0) |
| 61 | + val lineWidth = textPaint.measureText( |
| 62 | + config.text, |
| 63 | + startIndex, |
| 64 | + (startIndex + it.length).coerceAtMost(config.text.length) |
| 65 | + ).toInt() |
| 66 | + maxLineWidth = max(maxLineWidth, lineWidth) |
| 67 | + } |
| 68 | + |
| 69 | + val staticLayout = |
| 70 | + StaticLayout.Builder.obtain( |
| 71 | + config.text, |
| 72 | + 0, |
| 73 | + config.text.length, |
| 74 | + textPaint, |
| 75 | + maxLineWidth |
| 76 | + ) |
| 77 | + .setAlignment(Layout.Alignment.ALIGN_NORMAL) |
| 78 | + .build() |
| 79 | + |
| 80 | + val textWidth = staticLayout.width.toFloat().coerceAtLeast(1f) |
| 81 | + val textHeight = staticLayout.height.toFloat().coerceAtLeast(1f) |
| 82 | + |
| 83 | + // C2a: delegate cell sizing to the shared commonMain engine core (behavior-identical |
| 84 | + // formulas; pinned by WatermarkCellGoldenTest). Verified rendering parity on-device. |
| 85 | + val fixWidth = WatermarkGeometry.rotatedCellWidth(textWidth, textHeight, config.degree) |
| 86 | + val fixHeight = WatermarkGeometry.rotatedCellHeight(textWidth, textHeight, config.degree) |
| 87 | + val finalWidth = WatermarkGeometry.horizontalGap(fixWidth.toInt(), config.hGap) |
| 88 | + val finalHeight = WatermarkGeometry.verticalGap(fixHeight.toInt(), config.vGap) |
| 89 | + val bitmap = Bitmap.createBitmap(finalWidth, finalHeight, Bitmap.Config.ARGB_8888) |
| 90 | + val canvas = Canvas(bitmap) |
| 91 | + if (showDebugRect) { |
| 92 | + val tmpPaint = Paint().apply { |
| 93 | + color = Color.RED |
| 94 | + strokeWidth = 1f |
| 95 | + style = Paint.Style.STROKE |
| 96 | + } |
| 97 | + canvas.drawRect(0f, 0f, finalWidth.toFloat(), finalHeight.toFloat(), tmpPaint) |
| 98 | + canvas.save() |
| 99 | + } |
| 100 | + // rotate by user input |
| 101 | + canvas.rotate( |
| 102 | + config.degree, |
| 103 | + (finalWidth / 2).toFloat(), |
| 104 | + (finalHeight / 2).toFloat() |
| 105 | + ) |
| 106 | + // draw text |
| 107 | + canvas.withSave { |
| 108 | + this.translate( |
| 109 | + ((finalWidth) / 2).toFloat(), |
| 110 | + ((finalHeight - staticLayout.getLineBottom(0) - staticLayout.getLineTop(0)) / 2).toFloat() |
| 111 | + ) |
| 112 | + staticLayout.draw(canvas) |
| 113 | + } |
| 114 | + |
| 115 | + if (showDebugRect) { |
| 116 | + canvas.restore() |
| 117 | + } |
| 118 | + val bitmapShader = BitmapShader( |
| 119 | + bitmap, |
| 120 | + tileMode, |
| 121 | + tileMode |
| 122 | + ) |
| 123 | + return@withContext WaterMarkShader( |
| 124 | + bitmapShader, |
| 125 | + bitmap.width, |
| 126 | + bitmap.height |
| 127 | + ) |
| 128 | + } |
| 129 | + |
| 130 | + /** |
| 131 | + * Build the icon watermark cell + REPEAT/CLAMP [BitmapShader]. Verbatim extraction of the former |
| 132 | + * `WaterMarkImageView.buildIconBitmapShader` (which now delegates here). Preserves the legacy |
| 133 | + * nearest-neighbor `Bitmap.createScaledBitmap(..., false)` behavior. |
| 134 | + */ |
| 135 | + suspend fun buildIconShader( |
| 136 | + imageInfo: ImageInfo, |
| 137 | + srcBitmap: Bitmap, |
| 138 | + config: WaterMark, |
| 139 | + textPaint: Paint, |
| 140 | + scale: Boolean, |
| 141 | + coroutineContext: CoroutineContext, |
| 142 | + ): WaterMarkShader? = withContext(coroutineContext) { |
| 143 | + if (srcBitmap.isRecycled) { |
| 144 | + return@withContext null |
| 145 | + } |
| 146 | + val tileMode = config.obtainTileMode() |
| 147 | + val showDebugRect = config.enableBounds |
| 148 | + val rawWidth = srcBitmap.width.toFloat().coerceAtLeast(1f) |
| 149 | + val rawHeight = srcBitmap.height.toFloat().coerceAtLeast(1f) |
| 150 | + |
| 151 | + // C2a: icon-cell sizing via the shared commonMain engine core (equivalence pinned by |
| 152 | + // WatermarkCellGoldenTest.iconCell_dimensions_match_geometry). |
| 153 | + val maxSize = WatermarkGeometry.diagonal(rawHeight, rawWidth) |
| 154 | + val finalWidth = WatermarkGeometry.horizontalGap(maxSize, config.hGap) |
| 155 | + val finalHeight = WatermarkGeometry.verticalGap(maxSize, config.vGap) |
| 156 | + // textSize represents scale ratio of icon. |
| 157 | + val scaleRatio = if (scale) { |
| 158 | + imageInfo.scaleX |
| 159 | + } else { |
| 160 | + 1f |
| 161 | + } * config.textSize / 14f |
| 162 | + |
| 163 | + val targetBitmap = Bitmap.createBitmap( |
| 164 | + (finalWidth * scaleRatio).toInt(), |
| 165 | + (finalHeight * scaleRatio).toInt(), |
| 166 | + Bitmap.Config.ARGB_8888 |
| 167 | + ) |
| 168 | + |
| 169 | + val canvas = Canvas(targetBitmap) |
| 170 | + |
| 171 | + val scaleBitmap = Bitmap.createScaledBitmap( |
| 172 | + srcBitmap, |
| 173 | + (rawWidth * scaleRatio).toInt(), (rawHeight * scaleRatio).toInt(), |
| 174 | + false |
| 175 | + ) |
| 176 | + |
| 177 | + if (showDebugRect) { |
| 178 | + val tmpPaint = Paint().apply { |
| 179 | + color = Color.RED |
| 180 | + strokeWidth = 1f |
| 181 | + style = Paint.Style.STROKE |
| 182 | + } |
| 183 | + canvas.drawRect(0f, 0f, finalWidth * scaleRatio, finalHeight * scaleRatio, tmpPaint) |
| 184 | + canvas.save() |
| 185 | + } |
| 186 | + canvas.rotate( |
| 187 | + config.degree, |
| 188 | + (finalWidth * scaleRatio / 2), |
| 189 | + (finalHeight * scaleRatio / 2) |
| 190 | + ) |
| 191 | + |
| 192 | + canvas.drawBitmap( |
| 193 | + scaleBitmap, |
| 194 | + (finalWidth * scaleRatio - scaleBitmap.width) / 2.toFloat(), |
| 195 | + (finalHeight * scaleRatio - scaleBitmap.height) / 2.toFloat(), |
| 196 | + textPaint |
| 197 | + ) |
| 198 | + if (showDebugRect) { |
| 199 | + canvas.restore() |
| 200 | + } |
| 201 | + val bitmapShader = BitmapShader( |
| 202 | + targetBitmap, |
| 203 | + tileMode, |
| 204 | + tileMode |
| 205 | + ) |
| 206 | + return@withContext WaterMarkShader( |
| 207 | + bitmapShader, |
| 208 | + targetBitmap.width, |
| 209 | + targetBitmap.height |
| 210 | + ) |
| 211 | + } |
| 212 | + |
| 213 | + /** |
| 214 | + * Draw the watermark cell [shader] over [canvas] — the composition step shared by preview |
| 215 | + * (`onDraw`) and export (`generateImage`). Verbatim unification of the two former branches: |
| 216 | + * |
| 217 | + * - REPEAT: `translate(left, top)` then fill `[regionWidth] x [regionHeight]` (the whole |
| 218 | + * image/drawable region is tiled). |
| 219 | + * - CLAMP : `translate(left + offsetX*regionWidth, top + offsetY*regionHeight)` then draw ONE |
| 220 | + * cell-sized decal (`shader.width x shader.height`). |
| 221 | + * |
| 222 | + * Preview passes the drawable bounds (`left=drawableBounds.left, top=drawableBounds.top, |
| 223 | + * region=drawableBounds.width()/height()`); export passes `left=0, top=0, region=bitmap size` |
| 224 | + * (its REPEAT branch had no translate — `translate(0,0)` is a no-op, so behavior is identical). |
| 225 | + * The null-shader edge cases (CLAMP → 0x0 rect; REPEAT → paint fills the region) are preserved. |
| 226 | + */ |
| 227 | + fun compose( |
| 228 | + canvas: Canvas, |
| 229 | + shader: WaterMarkShader?, |
| 230 | + tileMode: Shader.TileMode, |
| 231 | + paint: Paint, |
| 232 | + left: Float, |
| 233 | + top: Float, |
| 234 | + regionWidth: Float, |
| 235 | + regionHeight: Float, |
| 236 | + offsetX: Float, |
| 237 | + offsetY: Float, |
| 238 | + ) { |
| 239 | + paint.shader = shader?.bitmapShader |
| 240 | + canvas.withSave { |
| 241 | + if (tileMode == Shader.TileMode.CLAMP) { |
| 242 | + translate(left + offsetX * regionWidth, top + offsetY * regionHeight) |
| 243 | + drawRect( |
| 244 | + 0f, |
| 245 | + 0f, |
| 246 | + (shader?.width ?: 0).toFloat(), |
| 247 | + (shader?.height ?: 0).toFloat(), |
| 248 | + paint |
| 249 | + ) |
| 250 | + } else { |
| 251 | + translate(left, top) |
| 252 | + drawRect(0f, 0f, regionWidth, regionHeight, paint) |
| 253 | + } |
| 254 | + } |
| 255 | + } |
| 256 | +} |
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