libptouch を複数ソースに分割し src/lib に配置

- core / usb / print / status / png と libptouch_internal.h に分割
- 旧単一ファイル src/libptouch.c を削除
- CMake のソース一覧と include パスを更新
- README・libptouch.h の参照パスを追随

Made-with: Cursor

src/lib/libptouch_png.c

@@ -0,0 +1,164 @@
+/*
+ * libptouch — PNG → 1bit packed raster (libpng)
+ *
+ * Author: knb
+ * Email: knb@artif.org
+ */
+
+#include "libptouch_internal.h"
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include <png.h>
+
+void libptouch_free_raster(uint8_t *raster)
+{
+	free(raster);
+}
+
+libptouch_err_t libptouch_png_file_to_raster(libptouch_ctx *ctx, const char *path,
+					     const libptouch_png_options_t *options,
+					     uint8_t **out_raster, size_t *out_raster_bytes,
+					     libptouch_raster_params_t *out_params)
+{
+	if (!ctx || !path || !out_raster || !out_raster_bytes || !out_params) {
+		if (ctx)
+			ptouch_set_error(ctx, LIBPTOUCH_ERR_ARG, "null argument");
+		return LIBPTOUCH_ERR_ARG;
+	}
+
+	uint8_t thr = LIBPTOUCH_PNG_DEFAULT_THRESHOLD;
+	if (options)
+		thr = options->threshold;
+
+	*out_raster = NULL;
+	*out_raster_bytes = 0;
+	out_params->width_dots = 0;
+	out_params->height_dots = 0;
+	out_params->margin_mm = 0;
+
+	FILE *fp = fopen(path, "rb");
+	if (!fp) {
+		char buf[192];
+		snprintf(buf, sizeof(buf), "open %s: %s", path, strerror(errno));
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_IO, buf);
+		return LIBPTOUCH_ERR_IO;
+	}
+
+	unsigned char sig[8];
+	if (fread(sig, 1, 8, fp) != 8) {
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_IMAGE, "short read (not a PNG?)");
+		return LIBPTOUCH_ERR_IMAGE;
+	}
+	if (png_sig_cmp(sig, 0, 8) != 0) {
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_IMAGE, "not a PNG file");
+		return LIBPTOUCH_ERR_IMAGE;
+	}
+
+	png_structp png_ptr =
+	    png_create_read_struct(PNG_LIBPNG_VER_STRING, NULL, NULL, NULL);
+	if (!png_ptr) {
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_NOMEM, "png_create_read_struct failed");
+		return LIBPTOUCH_ERR_NOMEM;
+	}
+	png_infop info_ptr = png_create_info_struct(png_ptr);
+	if (!info_ptr) {
+		png_destroy_read_struct(&png_ptr, NULL, NULL);
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_NOMEM, "png_create_info_struct failed");
+		return LIBPTOUCH_ERR_NOMEM;
+	}
+
+	if (setjmp(png_jmpbuf(png_ptr))) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_IMAGE, "PNG decode error");
+		return LIBPTOUCH_ERR_IMAGE;
+	}
+
+	png_init_io(png_ptr, fp);
+	png_set_sig_bytes(png_ptr, 8);
+
+	const int transforms = (int)(PNG_TRANSFORM_EXPAND | PNG_TRANSFORM_STRIP_16 |
+				     PNG_TRANSFORM_GRAY_TO_RGB);
+	png_read_png(png_ptr, info_ptr, transforms, NULL);
+
+	png_uint_32 width = png_get_image_width(png_ptr, info_ptr);
+	png_uint_32 height = png_get_image_height(png_ptr, info_ptr);
+	int channels = (int)png_get_channels(png_ptr, info_ptr);
+	png_bytepp rows = png_get_rows(png_ptr, info_ptr);
+
+	if (width == 0 || height == 0 || !rows) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_IMAGE, "invalid PNG dimensions");
+		return LIBPTOUCH_ERR_IMAGE;
+	}
+	if (width > 100000u || height > 100000u) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_IMAGE, "PNG dimensions too large");
+		return LIBPTOUCH_ERR_IMAGE;
+	}
+	if (channels != 3 && channels != 4) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_IMAGE, "unsupported PNG channel count");
+		return LIBPTOUCH_ERR_IMAGE;
+	}
+
+	size_t row_bytes = ((size_t)width + 7u) / 8u;
+	if (height > SIZE_MAX / row_bytes) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_IMAGE, "raster size overflow");
+		return LIBPTOUCH_ERR_IMAGE;
+	}
+	size_t total = row_bytes * (size_t)height;
+	uint8_t *out = (uint8_t *)calloc(1, total);
+	if (!out) {
+		png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+		fclose(fp);
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_NOMEM, "calloc raster failed");
+		return LIBPTOUCH_ERR_NOMEM;
+	}
+
+	for (png_uint_32 y = 0; y < height; y++) {
+		const png_byte *row = rows[y];
+		uint8_t *dst_row = out + (size_t)y * row_bytes;
+		for (png_uint_32 x = 0; x < width; x++) {
+			size_t o = (size_t)x * (size_t)channels;
+			unsigned r = row[o + 0];
+			unsigned g = row[o + 1];
+			unsigned b = row[o + 2];
+			unsigned a = channels == 4 ? row[o + 3] : 255u;
+			if (a < 128u) {
+				continue;
+			}
+			unsigned yv = (77u * r + 150u * g + 29u * b) >> 8;
+			int black = (yv < (unsigned)thr) ? 1 : 0;
+			if (!black)
+				continue;
+			size_t bit = (size_t)x % 8u;
+			size_t byte = (size_t)x / 8u;
+			dst_row[byte] |= (uint8_t)(1u << (7u - bit));
+		}
+	}
+
+	png_destroy_read_struct(&png_ptr, &info_ptr, NULL);
+	fclose(fp);
+
+	out_params->width_dots = (uint32_t)width;
+	out_params->height_dots = (uint32_t)height;
+	out_params->margin_mm = 0;
+	*out_raster = out;
+	*out_raster_bytes = total;
+	ptouch_set_error(ctx, LIBPTOUCH_OK, "");
+	return LIBPTOUCH_OK;
+}