pbio/image/media: Add mechanism for images.

bricks/_common/common.mk

@@ -162,6 +162,7 @@ DFU = $(TOP)/tools/dfu.py
 PYDFU = $(TOP)/tools/pydfu.py
 PYBRICKSDEV = pybricksdev
 METADATA = $(PBTOP)/tools/metadata.py
+MEDIA_CONVERT = $(PBTOP)/lib/pbio/src/image/media.py
 OPENOCD ?= openocd
 OPENOCD_CONFIG ?= openocd_stm32$(PB_MCU_SERIES_LCASE).cfg
 TEXT0_ADDR ?= 0x08000000
@@ -549,6 +550,11 @@ ifneq ($(PB_MCU_FAMILY),TIAM1808)
 SRC_S += lib/pbio/platform/$(PBIO_PLATFORM)/startup.s
 endif
 
+ifeq ($(PB_MEDIA),1)
+PYBRICKS_PYBRICKS_SRC_C += $(BUILD)/pb_type_image_attributes.c
+PBIO_SRC_C += $(BUILD)/pbio_image_media.c
+endif
+
 OBJ = $(PY_O)
 OBJ += $(addprefix $(BUILD)/, $(SRC_S:.s=.o))
 OBJ += $(addprefix $(BUILD)/, $(PY_EXTRA_SRC_C:.c=.o))
@@ -664,6 +670,10 @@ else
 FW_SECTIONS :=
 endif
 
+$(BUILD)/pbio_image_media.c $(BUILD)/pb_type_image_attributes.c: $(MEDIA_CONVERT)
+	$(ECHO) "MEDIA generating image media files"
+	$(Q)$(PYTHON) $(MEDIA_CONVERT) $(BUILD)
+
 $(BUILD)/firmware.elf: $(LD_FILES) $(OBJ)
 	$(ECHO) "LINK $@"
 	$(Q)$(CC) $(CFLAGS) $(LDFLAGS) -o $@ $(OBJ) $(LIBS)

bricks/ev3/Makefile

@@ -3,5 +3,6 @@ PB_MCU_FAMILY = TIAM1808
 
 PB_LIB_UMM_MALLOC = 1
 PB_LIB_BTSTACK = 1
+PB_MEDIA = 1
 
 include ../_common/common.mk

bricks/ev3/mpconfigport.h

@@ -49,6 +49,7 @@
 #define PYBRICKS_PY_PARAMETERS_BUTTON           (1)
 #define PYBRICKS_PY_PARAMETERS_ICON             (1)
 #define PYBRICKS_PY_PARAMETERS_IMAGE            (1)
+#define PYBRICKS_PY_PARAMETERS_IMAGE_FILE       (1)
 #define PYBRICKS_PY_DEVICES                     (1)
 #define PYBRICKS_PY_PUPDEVICES                  (0)
 #define PYBRICKS_PY_PUPDEVICES_REMOTE           (0)

bricks/nxt/mpconfigport.h

@@ -45,6 +45,7 @@
 #define PYBRICKS_PY_PARAMETERS_BUTTON           (1)
 #define PYBRICKS_PY_PARAMETERS_ICON             (0)
 #define PYBRICKS_PY_PARAMETERS_IMAGE            (1)
+#define PYBRICKS_PY_PARAMETERS_IMAGE_FILE       (0)
 #define PYBRICKS_PY_DEVICES                     (1)
 #define PYBRICKS_PY_ROBOTICS                    (1)
 #define PYBRICKS_PY_ROBOTICS_DRIVEBASE_GYRO     (0)

bricks/virtualhub/Makefile

@@ -7,5 +7,6 @@ PB_FROZEN_MODULES = 1
 MICROPY_ROM_TEXT_COMPRESSION = 1
 PB_LIB_UMM_MALLOC = 1
 PB_LIB_BTSTACK = 1
+PB_MEDIA = 1
 
 include ../_common/common.mk

bricks/virtualhub/mpconfigport.h

@@ -45,6 +45,7 @@
 #define PYBRICKS_PY_PARAMETERS_BUTTON           (1)
 #define PYBRICKS_PY_PARAMETERS_ICON             (0)
 #define PYBRICKS_PY_PARAMETERS_IMAGE            (1)
+#define PYBRICKS_PY_PARAMETERS_IMAGE_FILE       (1)
 #define PYBRICKS_PY_PUPDEVICES                  (1)
 #define PYBRICKS_PY_PUPDEVICES_REMOTE           (1)
 #define PYBRICKS_PY_DEVICES                     (1)

lib/pbio/include/pbio/image.h

@@ -69,6 +69,25 @@ typedef struct _pbio_image_t {
     uint8_t print_value;
 } pbio_image_t;
 
+/**
+ * Compressed monochrome image.
+ */
+typedef struct _pbio_image_monochrome_t {
+    /**
+     * Width of the image, or number of columns.
+     */
+    int width;
+    /**
+     * Height of the image, or number of rows.
+     */
+    int height;
+    /**
+     * One byte is 8 pixels. High is black, low is transparent. Most
+     * significant bit is first pixel.
+     */
+    const uint8_t *data;
+} pbio_image_monochrome_t;
+
 /**
  * Coordinates of a rectangle.
  */
@@ -107,6 +126,9 @@ void pbio_image_draw_image(pbio_image_t *image, const pbio_image_t *source,
 void pbio_image_draw_image_transparent(pbio_image_t *image,
     const pbio_image_t *source, int x, int y, uint8_t value);
 
+void pbio_image_draw_image_transparent_from_monochrome(pbio_image_t *image,
+    const pbio_image_monochrome_t *source, int x, int y, uint8_t value);
+
 void pbio_image_draw_pixel(pbio_image_t *image, int x, int y, uint8_t value);
 
 void pbio_image_draw_hline(pbio_image_t *image, int x, int y, int l,

lib/pbio/src/image/image.c

@@ -196,6 +196,53 @@ void pbio_image_draw_image_transparent(pbio_image_t *image,
     }
 }
 
+/**
+ * Draw an image inside another image with transparency. The source is
+ * a compressed monochrome image.
+ *
+ * @param [in] image   Destination image to draw into.
+ * @param [in] source  Source image.
+ * @param [in] x       X coordinate of the top-left point in destination
+ *                     image.
+ * @param [in] y       Y coordinate of the top-left point in destination
+ *                     image.
+ * @param [in] value   Pixel value in destination for black.
+ *
+ * Source image pixels are copied into destination image. When a source pixel
+ * matches the transparent value, the corresponding destination pixel is left
+ * untouched.
+ *
+ * Clipping: drawing is clipped to destination image dimensions.
+ */
+void pbio_image_draw_image_transparent_from_monochrome(pbio_image_t *image,
+    const pbio_image_monochrome_t *source, int x, int y, uint8_t value) {
+    // Clipping.
+    int ox = x;
+    int oy = y;
+    int x2 = x + source->width;
+    int y2 = y + source->height;
+    clip_or_return(x, x2, image->width);
+    clip_or_return(y, y2, image->height);
+
+    // Initial index in source.
+    size_t index = (y - oy) * source->width + (x - ox);
+
+    // Draw pixels.
+    uint8_t *dst = image->pixels + y * image->stride + x;
+    int w = x2 - x;
+    for (int h = y2 - y; h; h--) {
+        for (int i = w; i; i--) {
+            if (source->data[index / 8] & (1 << (7 - index % 8))) {
+                *dst = value;
+            }
+            index++;
+            dst++;
+        }
+        dst += image->stride - w;
+        index += source->width - w;
+    }
+}
+
 /**
  * Draw a single pixel.
  * @param [in] image  Image to draw into.

lib/pbio/src/image/media.py

@@ -0,0 +1,131 @@
+#!/usr/bin/env python3
+import argparse
+from pathlib import Path
+from PIL import Image
+import cairosvg
+
+# Take build directory as argument to save generated C files and PNG files.
+parser = argparse.ArgumentParser(description="Convert SVG files to PNG.")
+parser.add_argument("dest", help="Destination build folder for PNG files.")
+args = parser.parse_args()
+
+build_dir = Path(args.dest)
+build_dir.mkdir(parents=True, exist_ok=True)
+media_dir = Path(__file__).parent / "media"
+
+# Convert all SVG files in media_dir to PNG and save in build_dir if not already present.
+svg_files = media_dir.rglob("*.svg")
+for svg in svg_files:
+    png = svg.with_suffix(".png").name
+    png_path = build_dir / png
+    if png_path.exists():
+        continue
+    with open(svg, "rb") as svg_file:
+        png_bytes = cairosvg.svg2png(file_obj=svg_file)
+        with open(png_path, "wb") as out_png:
+            out_png.write(png_bytes)
+
+# Collect all image files in media_dir (png, bmp, jpg) and build_dir (png), including subfolders.
+media_images = (
+    list(media_dir.rglob("*.png"))
+    + list(media_dir.rglob("*.bmp"))
+    + list(media_dir.rglob("*.jpg"))
+    + list(build_dir.rglob("*.png"))
+)
+
+
+# Convert rgba to monochrome, treating fully transparent pixels as white.
+def is_black(r, g, b, a):
+    if a == 0:
+        return 0
+    return 1 if (r + g + b) < (128 * 3) else 0
+
+
+def image_to_8bit_map(img):
+    img = img.convert("RGBA")
+    width, height = img.size
+    pixels = img.load()
+    mono = [is_black(*pixels[x, y]) for y in range(height) for x in range(width)]
+
+    # go in chunks of 8 pixels and pack into a byte
+    data = []
+    for i in range(0, len(mono), 8):
+        byte = 0
+        for j in range(8):
+            if i + j < len(mono):
+                byte |= mono[i + j] << (7 - j)
+        data.append(byte)
+
+    return width, height, bytes(data)
+
+
+# Process each image.
+results = {}
+for img_path in media_images:
+    with Image.open(img_path) as img:
+        name = Path(img_path.name).stem
+        width, height, bin_data = image_to_8bit_map(img)
+        results[name] = (width, height, bin_data)
+
+
+externs = ""
+structs = ""
+qstrtab = ""
+
+for name in sorted(results):
+    width, height, bin_data = results[name]
+
+    # Parse bytes for printing.
+    bytes_per_line = 12
+    lines = []
+    for i in range(0, len(bin_data), bytes_per_line):
+        chunk = bin_data[i : i + bytes_per_line]
+        line = "    " + ", ".join(f"0x{val:02x}" for val in chunk)
+        lines.append(line)
+    data_literal = ",\n".join(lines) + ","
+
+    # Printed C structs.
+    structs += f"static const uint8_t {name}_data[] = {{\n{data_literal}\n}};\n\n"
+    structs += (
+        f"const pbio_image_monochrome_t pbio_image_media_{name} = {{\n"
+        f"    .width = {width},\n"
+        f"    .height = {height},\n"
+        f"    .data = {name}_data,\n"
+        f"}};\n"
+    )
+
+    # Printed header and QSTR table entries.
+    externs += f"extern const pbio_image_monochrome_t pbio_image_media_{name};\n\n"
+    qstrtab += f"    {{ MP_ROM_QSTR(MP_QSTR_{name.upper()}), MP_ROM_PTR(&pbio_image_media_{name}) }},\n"
+
+
+HEADER = """// SPDX-License-Identifier: MIT
+//Copyright (c) 2025 The Pybricks Authors
+
+#include <pbio/image.h>
+"""
+
+with open(build_dir / "pbio_image_media.c", "w") as f:
+    f.write(HEADER)
+    f.write('#include "pbio_image_media.h"\n\n')
+    f.write(structs)
+
+with open(build_dir / "pbio_image_media.h", "w") as f:
+    f.write(HEADER)
+    f.write("#ifndef _PBIO_IMAGE_MEDIA_H_\n")
+    f.write("#define _PBIO_IMAGE_MEDIA_H_\n\n")
+    f.write(externs)
+    f.write("#endif // _PBIO_IMAGE_MEDIA_H_\n")
+
+with open(build_dir / "pb_type_image_attributes.c", "w") as f:
+    f.write(HEADER)
+    f.write('#include "pbio_image_media.h"\n\n')
+    f.write("#include <py/obj.h>\n\n")
+    f.write(
+        "static const mp_rom_map_elem_t pb_type_image_attributes_dict_table[] = {\n"
+    )
+    f.write(qstrtab)
+    f.write("};\n")
+    f.write(
+        "MP_DEFINE_CONST_DICT(pb_type_image_attributes_dict, pb_type_image_attributes_dict_table);"
+    )