wip: scratch work for auto-rendering band-interleaved data

packages/deck.gl-geotiff/src/geotiff/render-pipeline.ts

@@ -1,10 +1,15 @@
-import { Photometric, SampleFormat } from "@cogeotiff/core";
+import {
+  Photometric,
+  PlanarConfiguration,
+  SampleFormat,
+} from "@cogeotiff/core";
 import type { RasterModule } from "@developmentseed/deck.gl-raster/gpu-modules";
 import {
   BlackIsZero,
   CMYKToRGB,
   Colormap,
   CreateTexture,
+  CreateTextureBands,
   cieLabToRGB,
   FilterNoDataVal,
   MaskTexture,
@@ -21,14 +26,23 @@ import type { GetTileDataOptions } from "../cog-layer";
 import { addAlphaChannel } from "./geotiff";
 import { inferTextureFormat } from "./texture";
 
-export type TextureDataT = {
+type BaseTextureData = {
   height: number;
   width: number;
   byteLength: number;
-  texture: Texture;
   mask?: Texture;
 };
 
+type InterleavedTexture = {
+  texture: Texture;
+} & BaseTextureData;
+
+type BandSeparateTexture = {
+  bands: Texture[];
+} & BaseTextureData;
+
+export type TextureDataT = InterleavedTexture | BandSeparateTexture;
+
 /**
  * A raster module that can be "unresolved", meaning that its props may come
  * from the result of `getTileData`.
@@ -93,17 +107,30 @@ function createUnormPipeline(
     photometric,
     sampleFormat,
     samplesPerPixel,
+    planarConfiguration,
     nodata,
   } = geotiff.cachedTags;
 
-  const renderPipeline: UnresolvedRasterModule<TextureDataT>[] = [
-    {
+  const renderPipeline: UnresolvedRasterModule<TextureDataT>[] = [];
+
+  if (planarConfiguration === PlanarConfiguration.Contig) {
+    renderPipeline.push({
       module: CreateTexture,
       props: {
-        textureName: (data: TextureDataT) => data.texture,
+        textureName: (data: InterleavedTexture) => data.texture,
       },
-    },
-  ];
+    });
+  } else {
+    renderPipeline.push({
+      module: CreateTextureBands,
+      props: {
+        band1: (data: BandSeparateTexture) => data.bands[0],
+        band2: (data: BandSeparateTexture) => data.bands[1] ?? undefined,
+        band3: (data: BandSeparateTexture) => data.bands[2] ?? undefined,
+        band4: (data: BandSeparateTexture) => data.bands[3] ?? undefined,
+      },
+    });
+  }
 
   if (nodata !== null) {
     // Since values are 0-1 for unorm textures, scale nodata to [0, 1]

packages/deck.gl-raster/src/gpu-modules/create-texture-bands.ts

@@ -0,0 +1,57 @@
+import type { Texture } from "@luma.gl/core";
+import type { ShaderModule } from "@luma.gl/shadertools";
+
+// Props expected by the CreateTextureBands shader module.
+// Each band is a single-channel (depth=1) texture. Unused bands should be
+// omitted — the shader reads only the bands that are declared.
+export type CreateTextureBandsProps = {
+  band1: Texture;
+  band2?: Texture;
+  band3?: Texture;
+  band4?: Texture;
+};
+
+/**
+ * A shader module that assembles up to four single-band textures into a single
+ * vec4 color. Each input texture is expected to have a single channel; the red
+ * channel (.r) of each is read and placed into the corresponding RGBA slot.
+ *
+ * Bands are always read in order: band1 → R, band2 → G, band3 → B, band4 → A.
+ * Missing bands default to 0.0.
+ */
+export const CreateTextureBands = {
+  name: "create-texture-bands",
+  inject: {
+    "fs:#decl": /* glsl */ `
+      uniform sampler2D band1;
+      uniform sampler2D band2;
+      uniform sampler2D band3;
+      uniform sampler2D band4;
+      uniform int bandCount;
+    `,
+    "fs:DECKGL_FILTER_COLOR": /* glsl */ `
+      float r = texture(band1, geometry.uv).r;
+      float g = bandCount >= 2 ? texture(band2, geometry.uv).r : 0.0;
+      float b = bandCount >= 3 ? texture(band3, geometry.uv).r : 0.0;
+      float a = bandCount >= 4 ? texture(band4, geometry.uv).r : 1.0;
+      color = vec4(r, g, b, a);
+    `,
+  },
+  getUniforms: (props: Partial<CreateTextureBandsProps>) => {
+    const count =
+      props.band4 != null
+        ? 4
+        : props.band3 != null
+          ? 3
+          : props.band2 != null
+            ? 2
+            : 1;
+    return {
+      band1: props.band1,
+      band2: props.band2,
+      band3: props.band3,
+      band4: props.band4,
+      bandCount: count,
+    };
+  },
+} as const satisfies ShaderModule<CreateTextureBandsProps>;

packages/deck.gl-raster/src/gpu-modules/index.ts

@@ -1,4 +1,4 @@
 export {
   BlackIsZero,
   CMYKToRGB,
   cieLabToRGB,
@@ -7,6 +7,7 @@
 } from "./color";
 export { Colormap } from "./colormap";
 export { CreateTexture } from "./create-texture";
+export { CreateTextureBands, type CreateTextureBandsProps } from "./create-texture-bands";
 export { FilterNoDataVal } from "./filter-nodata";
 export { MaskTexture } from "./mask-texture";
 export type { RasterModule } from "./types";