ptouch-label/ptouch-print のオプション整理と trim-right 対応を反映

CLIヘルプ文言を簡潔化しつつ、右余白トリム機能と関連API・ドキュメント更新をまとめて取り込み、PNG/SVG/テンプレート経路での利用体験を揃える。

Made-with: Cursor

src/lib/libptouch_trim.c

@@ -0,0 +1,84 @@
+/*
+ * libptouch — raster right blank trim
+ *
+ * Author: knb
+ * Email: knb@artif.org
+ */
+
+#include "libptouch_internal.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+libptouch_err_t libptouch_trim_right_blank_columns(
+	libptouch_ctx *ctx, const uint8_t *data, size_t data_len,
+	const libptouch_raster_params_t *in_params, uint16_t right_padding_dots,
+	uint8_t **out_raster, size_t *out_raster_bytes,
+	libptouch_raster_params_t *out_params)
+{
+	if (!ctx || !data || !in_params || !out_raster || !out_raster_bytes ||
+	    !out_params) {
+		if (ctx)
+			ptouch_set_error(ctx, LIBPTOUCH_ERR_ARG, "null argument");
+		return LIBPTOUCH_ERR_ARG;
+	}
+
+	libptouch_err_t v = libptouch_check_raster(ctx, data, data_len, in_params);
+	if (v != LIBPTOUCH_OK)
+		return v;
+
+	uint32_t width = in_params->width_dots;
+	uint32_t height = in_params->height_dots;
+	size_t row_bytes = ((size_t)width + 7u) / 8u;
+	int32_t rightmost = -1;
+
+	for (uint32_t y = 0; y < height; y++) {
+		const uint8_t *row = data + (size_t)y * row_bytes;
+		for (int32_t x = (int32_t)width - 1; x >= 0; x--) {
+			uint8_t b = row[(size_t)x / 8u];
+			uint8_t bit = (uint8_t)(7u - ((uint32_t)x % 8u));
+			if (((b >> bit) & 1u) == 0)
+				continue;
+			if (x > rightmost)
+				rightmost = x;
+			break;
+		}
+	}
+
+	uint32_t new_width = width;
+	if (rightmost >= 0) {
+		uint32_t trimmed = (uint32_t)(rightmost + 1);
+		uint32_t padded = trimmed + (uint32_t)right_padding_dots;
+		if (padded > width)
+			padded = width;
+		if (padded < width)
+			new_width = padded;
+	}
+
+	size_t new_row_bytes = ((size_t)new_width + 7u) / 8u;
+	size_t total = new_row_bytes * (size_t)height;
+	uint8_t *out = (uint8_t *)calloc(1u, total);
+	if (!out) {
+		ptouch_set_error(ctx, LIBPTOUCH_ERR_NOMEM, "calloc raster failed");
+		return LIBPTOUCH_ERR_NOMEM;
+	}
+
+	uint8_t last_mask = 0xFFu;
+	if ((new_width % 8u) != 0u)
+		last_mask = (uint8_t)((0xFFu << (8u - (new_width % 8u))) & 0xFFu);
+
+	for (uint32_t y = 0; y < height; y++) {
+		const uint8_t *src = data + (size_t)y * row_bytes;
+		uint8_t *dst = out + (size_t)y * new_row_bytes;
+		memcpy(dst, src, new_row_bytes);
+		dst[new_row_bytes - 1u] &= last_mask;
+	}
+
+	*out_raster = out;
+	*out_raster_bytes = total;
+	out_params->width_dots = new_width;
+	out_params->height_dots = height;
+	out_params->margin_mm = in_params->margin_mm;
+	ptouch_set_error(ctx, LIBPTOUCH_OK, "");
+	return LIBPTOUCH_OK;
+}