raster/vector: allow for separator height being > twice row height

(ticket #353, props Simon Resch)

backend/output.c

@@ -1,7 +1,7 @@
 /*  output.c - Common routines for raster/vector
 
     libzint - the open source barcode library
-    Copyright (C) 2020-2025 Robin Stuart <rstuart114@gmail.com>
+    Copyright (C) 2020-2026 Robin Stuart <rstuart114@gmail.com>
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -846,7 +846,7 @@ INTERNAL float zint_out_large_bar_height(struct zint_symbol *symbol, const int s
                 large_bar_height = z_stripf(roundf(large_bar_height * si) / si);
             }
             symbol->height = z_stripf(large_bar_height * zero_count + fixed_height);
-            /* Note should never happen that have both zero_count and round_rows */
+        /* Note should never happen that have both zero_count and round_rows */
         } else {
             if (round_rows) {
                 float total_height = 0.0f;

backend/raster.c

@@ -1,7 +1,7 @@
 /* raster.c - Handles output to raster files */
 /*
     libzint - the open source barcode library
-    Copyright (C) 2009-2025 Robin Stuart <rstuart114@gmail.com>
+    Copyright (C) 2009-2026 Robin Stuart <rstuart114@gmail.com>
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -290,6 +290,10 @@ static void draw_bar_line(unsigned char *pixelbuf, const int xpos, const int xle
             const int image_width, const int fill) {
     unsigned char *pb = pixelbuf + ((size_t) image_width * ypos) + xpos;
 
+    assert(xpos >= 0);
+    assert(xlen >= 0);
+    assert(ypos >= 0);
+
     memset(pb, fill, xlen);
 }
 
@@ -300,6 +304,10 @@ static void copy_bar_line(unsigned char *pixelbuf, const int xpos, const int xle
     const int ye = ypos + ylen > image_height ? image_height : ypos + ylen; /* Defensive, should never happen */
     unsigned char *pb = pixelbuf + ((size_t) image_width * ypos) + xpos;
 
+    assert(xpos >= 0);
+    assert(xlen >= 0);
+    assert(ypos >= 0);
+    assert(ylen >= 0);
     assert(ypos + ylen <= image_height); /* Trigger assert if "should never happen" happens */
 
     for (y = ypos + 1; y < ye; y++) {
@@ -314,6 +322,10 @@ static void draw_bar(unsigned char *pixelbuf, const int xpos, const int xlen, co
     const int ye = ypos + ylen > image_height ? image_height : ypos + ylen; /* Defensive, should never happen */
     unsigned char *pb = pixelbuf + ((size_t) image_width * ypos) + xpos;
 
+    assert(xpos >= 0);
+    assert(xlen >= 0);
+    assert(ypos >= 0);
+    assert(ylen >= 0);
     assert(ypos + ylen <= image_height); /* Trigger assert if "should never happen" happens */
 
     for (y = ypos; y < ye; y++, pb += image_width) {
@@ -1354,11 +1366,15 @@ static int plot_raster_default(struct zint_symbol *symbol, const int rotate_angl
             sep_height = symbol->option_3;
         }
         sep_height_si = (int) (sep_height * si);
+        if (sep_height_si > row_heights_si[0] * 2) { /* Ticket 353, props Simon Resch */
+            sep_height_si = row_heights_si[0] * 2;
+        }
         sep_yoffset_si = yoffset_si + row_heights_si[0] - sep_height_si / 2;
         if (is_codablockf) {
             /* Avoid 11-module start and 13-module stop chars */
             sep_xoffset_si += 11 * si;
             sep_width_si -= (11 + 13) * si;
+            assert(sep_width_si >= 0);
         }
         for (r = 1; r < symbol->rows; r++) {
             draw_bar(pixelbuf, sep_xoffset_si, sep_width_si, sep_yoffset_si, sep_height_si, image_width, image_height,

backend/tests/test_raster.c

@@ -742,6 +742,7 @@ static void test_row_separator(const testCtx *const p_ctx) {
         int border_width;
         int option_1;
         int option_3;
+        float height;
         const char *data;
         int ret;
 
@@ -756,15 +757,18 @@ static void test_row_separator(const testCtx *const p_ctx) {
     };
     /* s/\/\*[ 0-9]*\*\//\=printf("\/\*%3d*\/", line(".") - line("'<")): */
     static const struct item data[] = {
-        /*  0*/ { BARCODE_CODABLOCKF, -1, -1, -1, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 },
+        /*  0*/ { BARCODE_CODABLOCKF, -1, -1, -1, 0, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 },
-        /*  1*/ { BARCODE_CODABLOCKF, -1, -1, 0, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 }, /* Same as default */
+        /*  1*/ { BARCODE_CODABLOCKF, -1, -1, 0, 0, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 }, /* Same as default */
-        /*  2*/ { BARCODE_CODABLOCKF, -1, -1, 1, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 }, /* Same as default */
+        /*  2*/ { BARCODE_CODABLOCKF, -1, -1, 1, 0, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 }, /* Same as default */
-        /*  3*/ { BARCODE_CODABLOCKF, -1, -1, 2, "A", 0, 20, 2, 101, 242, 44, 20, 42, 4 },
+        /*  3*/ { BARCODE_CODABLOCKF, -1, -1, 2, 0, "A", 0, 20, 2, 101, 242, 44, 20, 42, 4 },
-        /*  4*/ { BARCODE_CODABLOCKF, -1, -1, 3, "A", 0, 20, 2, 101, 242, 44, 19, 42, 6 },
+        /*  4*/ { BARCODE_CODABLOCKF, -1, -1, 3, 0, "A", 0, 20, 2, 101, 242, 44, 19, 42, 6 },
-        /*  5*/ { BARCODE_CODABLOCKF, -1, -1, 4, "A", 0, 20, 2, 101, 242, 44, 18, 42, 8 },
+        /*  5*/ { BARCODE_CODABLOCKF, -1, -1, 4, 0, "A", 0, 20, 2, 101, 242, 44, 18, 42, 8 },
-        /*  6*/ { BARCODE_CODABLOCKF, -1, -1, 5, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 }, /* > 4 ignored, same as default */
+        /*  6*/ { BARCODE_CODABLOCKF, -1, -1, 5, 0, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 }, /* > 4 ignored, same as default */
-        /*  7*/ { BARCODE_CODABLOCKF, -1, 1, -1, "A", 0, 5, 1, 46, 132, 14, 0, 20 + 2, 2 }, /* CODE128 top separator, add 2 to skip over end of start char; note no longer includes HRT */
+        /*  7*/ { BARCODE_CODABLOCKF, -1, 1, -1, 0, "A", 0, 5, 1, 46, 132, 14, 0, 20 + 2, 2 }, /* CODE128 top separator, add 2 to skip over end of start char; note no longer includes HRT */
-        /*  8*/ { BARCODE_CODABLOCKF, 0, -1, -1, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 }, /* Border width zero, same as default */
+        /*  8*/ { BARCODE_CODABLOCKF, 0, -1, -1, 0, "A", 0, 20, 2, 101, 242, 44, 21, 42, 2 }, /* Border width zero, same as default */
+        /*  9*/ { BARCODE_CODABLOCKF, -1, -1, 4, 2, "A", 0, 2, 2, 101, 242, 8, 0, 42, 8 }, /* Ticket #353, props Simon Resch */
+        /* 10*/ { BARCODE_CODABLOCKF, -1, -1, 4, 1.5, "A", 0, 2, 2, 101, 242, 8, 0, 42, 8 }, /* Height gets rounded up as not integral  */
+        /* 11*/ { BARCODE_CODABLOCKF, -1, -1, 4, 1, "A", 0, 1, 2, 101, 242, 6, 0, 42, 6 },
     };
     const int data_size = ARRAY_SIZE(data);
     int i, length, ret;
@@ -785,6 +789,9 @@ static void test_row_separator(const testCtx *const p_ctx) {
         if (data[i].border_width != -1) {
             symbol->border_width = data[i].border_width;
         }
+        if (data[i].height) {
+            symbol->height = data[i].height;
+        }
 
         ret = ZBarcode_Encode_and_Buffer(symbol, (unsigned char *) data[i].data, length, 0);
         assert_equal(ret, data[i].ret, "i:%d ret %d != %d (%s)\n", i, ret, data[i].ret, symbol->errtxt);
@@ -805,15 +812,17 @@ static void test_row_separator(const testCtx *const p_ctx) {
             assert_nonzero(separator_bits_set, "i:%d (%s) separator_bits_set (%d, %d) zero\n", i, testUtilBarcodeName(data[i].symbology), j, data[i].expected_separator_col);
         }
 
-        if (symbol->rows > 1) {
+        if (data[i].expected_separator_row > 0) {
-            j = data[i].expected_separator_row - 1;
+            if (symbol->rows > 1) {
-            separator_bits_set = is_row_column_black(symbol, j, data[i].expected_separator_col + 2); /* Need to add 2 to skip to 1st blank of start row character */
+                j = data[i].expected_separator_row - 1;
-            assert_zero(separator_bits_set, "i:%d (%s) separator_bits_set (%d, %d) before non-zero\n", i, testUtilBarcodeName(data[i].symbology), j, data[i].expected_separator_col);
+                separator_bits_set = is_row_column_black(symbol, j, data[i].expected_separator_col + 2); /* Need to add 2 to skip to 1st blank of start row character */
-        }
+                assert_zero(separator_bits_set, "i:%d (%s) separator_bits_set (%d, %d) before non-zero\n", i, testUtilBarcodeName(data[i].symbology), j, data[i].expected_separator_col);
+            }
 
-        j = data[i].expected_separator_row + data[i].expected_separator_height;
+            j = data[i].expected_separator_row + data[i].expected_separator_height;
-        separator_bits_set = is_row_column_black(symbol, j, data[i].expected_separator_col + 2); /* Need to add 2 to skip to 1st blank of start row character */
+            separator_bits_set = is_row_column_black(symbol, j, data[i].expected_separator_col + 2); /* Need to add 2 to skip to 1st blank of start row character */
-        assert_zero(separator_bits_set, "i:%d (%s) separator_bits_set (%d, %d) after non-zero\n", i, testUtilBarcodeName(data[i].symbology), j, data[i].expected_separator_col);
+            assert_zero(separator_bits_set, "i:%d (%s) separator_bits_set (%d, %d) after non-zero\n", i, testUtilBarcodeName(data[i].symbology), j, data[i].expected_separator_col);
+        }
 
         ZBarcode_Delete(symbol);
     }

backend/tests/test_vector.c

@@ -1123,7 +1123,7 @@ static void test_upcean_hrt(const testCtx *const p_ctx) {
                     i, testUtilBarcodeName(data[i].symbology), symbol->vector->height,
                     data[i].expected_vector_height);
 
-        if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) {
+        if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) { /* ZINT_DEBUG_TEST_PRINT 16 */
             testUtilVectorPrint(symbol);
         }
 
@@ -1165,6 +1165,7 @@ static void test_row_separator(const testCtx *const p_ctx) {
         int border_width;
         int option_1;
         int option_3;
+        float height;
         const char *data;
         int ret;
 
@@ -1177,15 +1178,18 @@ static void test_row_separator(const testCtx *const p_ctx) {
     };
     /* s/\/\*[ 0-9]*\*\//\=printf("\/\*%3d*\/", line(".") - line("'<")): */
     struct item data[] = {
-        /*  0*/ { BARCODE_CODABLOCKF, -1, -1, -1, "A", 0, 20, 2, 101, 42, 21, 2 },
+        /*  0*/ { BARCODE_CODABLOCKF, -1, -1, -1, 0, "A", 0, 20, 2, 101, 42, 21, 2 },
-        /*  1*/ { BARCODE_CODABLOCKF, -1, -1, 0, "A", 0, 20, 2, 101, 42, 21, 2 }, /* Same as default */
+        /*  1*/ { BARCODE_CODABLOCKF, -1, -1, 0, 0, "A", 0, 20, 2, 101, 42, 21, 2 }, /* Same as default */
-        /*  2*/ { BARCODE_CODABLOCKF, -1, -1, 1, "A", 0, 20, 2, 101, 42, 21, 2 }, /* Same as default */
+        /*  2*/ { BARCODE_CODABLOCKF, -1, -1, 1, 0, "A", 0, 20, 2, 101, 42, 21, 2 }, /* Same as default */
-        /*  3*/ { BARCODE_CODABLOCKF, -1, -1, 2, "A", 0, 20, 2, 101, 42, 20, 4 },
+        /*  3*/ { BARCODE_CODABLOCKF, -1, -1, 2, 0, "A", 0, 20, 2, 101, 42, 20, 4 },
-        /*  4*/ { BARCODE_CODABLOCKF, -1, -1, 3, "A", 0, 20, 2, 101, 42, 19, 6 },
+        /*  4*/ { BARCODE_CODABLOCKF, -1, -1, 3, 0, "A", 0, 20, 2, 101, 42, 19, 6 },
-        /*  5*/ { BARCODE_CODABLOCKF, -1, -1, 4, "A", 0, 20, 2, 101, 42, 18, 8 },
+        /*  5*/ { BARCODE_CODABLOCKF, -1, -1, 4, 0, "A", 0, 20, 2, 101, 42, 18, 8 },
-        /*  6*/ { BARCODE_CODABLOCKF, -1, -1, 5, "A", 0, 20, 2, 101, 42, 21, 2 }, /* > 4 ignored, same as default */
+        /*  6*/ { BARCODE_CODABLOCKF, -1, -1, 5, 0, "A", 0, 20, 2, 101, 42, 21, 2 }, /* > 4 ignored, same as default */
-        /*  7*/ { BARCODE_CODABLOCKF, -1, 1, -1, "A", 0, 5, 1, 46, 20, 0, 2 }, /* CODE128 top separator */
+        /*  7*/ { BARCODE_CODABLOCKF, -1, 1, -1, 0, "A", 0, 5, 1, 46, 20, 0, 2 }, /* CODE128 top separator */
-        /*  8*/ { BARCODE_CODABLOCKF, 0, -1, -1, "A", 0, 20, 2, 101, 42, 21, 2 }, /* Border width zero, same as default */
+        /*  8*/ { BARCODE_CODABLOCKF, 0, -1, -1, 0, "A", 0, 20, 2, 101, 42, 21, 2 }, /* Border width zero, same as default */
+        /*  9*/ { BARCODE_CODABLOCKF, -1, -1, 4, 2, "A", 0, 2, 2, 101, 42, 0, 8 }, /* Ticket #353, props Simon Resch */
+        /* 10*/ { BARCODE_CODABLOCKF, -1, -1, 4, 1.5, "A", 0, 1.5, 2, 101, 42, 0, 8 },
+        /* 11*/ { BARCODE_CODABLOCKF, -1, -1, 4, 1, "A", 0, 1, 2, 101, 42, 0, 8 },
     };
     int data_size = ARRAY_SIZE(data);
     int i, length, ret;
@@ -1206,6 +1210,9 @@ static void test_row_separator(const testCtx *const p_ctx) {
         if (data[i].border_width != -1) {
             symbol->border_width = data[i].border_width;
         }
+        if (data[i].height) {
+            symbol->height = data[i].height;
+        }
 
         ret = ZBarcode_Encode(symbol, TCU(data[i].data), length);
         assert_zero(ret, "i:%d ZBarcode_Encode(%d) ret %d != 0 %s\n", i, data[i].symbology, ret, symbol->errtxt);
@@ -1214,6 +1221,10 @@ static void test_row_separator(const testCtx *const p_ctx) {
         assert_zero(ret, "i:%d ZBarcode_Buffer_Vector(%d) ret %d != 0\n", i, data[i].symbology, ret);
         assert_nonnull(symbol->vector, "i:%d ZBarcode_Buffer_Vector(%d) vector NULL\n", i, data[i].symbology);
 
+        if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) { /* ZINT_DEBUG_TEST_PRINT 16 */
+            testUtilVectorPrint(symbol);
+        }
+
         assert_equal(symbol->height, data[i].expected_height, "i:%d (%d) symbol->height %.9g != %.9g\n", i, data[i].symbology, symbol->height, data[i].expected_height);
         assert_equal(symbol->rows, data[i].expected_rows, "i:%d (%d) symbol->rows %d != %d\n", i, data[i].symbology, symbol->rows, data[i].expected_rows);
         assert_equal(symbol->width, data[i].expected_width, "i:%d (%d) symbol->width %d != %d\n", i, data[i].symbology, symbol->width, data[i].expected_width);
@@ -1286,7 +1297,7 @@ static void test_stacking(const testCtx *const p_ctx) {
         assert_equal(symbol->width, data[i].expected_width, "i:%d (%d) symbol->width %d != %d\n", i, data[i].symbology, symbol->width, data[i].expected_width);
 
         if (data[i].expected_separator_y != -1) {
-            if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) {
+            if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) { /* ZINT_DEBUG_TEST_PRINT 16 */
                 testUtilVectorPrint(symbol);
             }
 
@@ -1424,7 +1435,7 @@ static void test_output_options(const testCtx *const p_ctx) {
         if (ret < ZINT_ERROR) {
             assert_nonnull(symbol->vector, "i:%d ZBarcode_Buffer_Vector(%d) vector NULL\n", i, data[i].symbology);
 
-            if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) {
+            if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) { /* ZINT_DEBUG_TEST_PRINT 16 */
                 testUtilVectorPrint(symbol);
             }
 
@@ -1558,7 +1569,7 @@ static void test_upcean_whitespace_width(const testCtx *const p_ctx) {
         assert_zero(ret, "i:%d ZBarcode_Buffer_Vector(%d) ret %d != 0\n", i, data[i].symbology, ret);
         assert_nonnull(symbol->vector, "i:%d ZBarcode_Buffer_Vector(%d) vector NULL\n", i, data[i].symbology);
 
-        if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) {
+        if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) { /* ZINT_DEBUG_TEST_PRINT 16 */
             testUtilVectorPrint(symbol);
         }
 
@@ -1656,7 +1667,7 @@ static void test_scale(const testCtx *const p_ctx) {
         assert_equal(ret, data[i].ret_vector, "i:%d ZBarcode_Buffer_Vector(%d) ret %d != %d (%s)\n", i, data[i].symbology, ret, data[i].ret_vector, symbol->errtxt);
         assert_nonnull(symbol->vector, "i:%d ZBarcode_Buffer_Vector(%d) vector NULL\n", i, data[i].symbology);
 
-        if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) {
+        if (p_ctx->index != -1 && (debug & ZINT_DEBUG_TEST_PRINT)) { /* ZINT_DEBUG_TEST_PRINT 16 */
             testUtilVectorPrint(symbol);
         }
 

backend/vector.c

@@ -1,7 +1,7 @@
 /*  vector.c - Creates vector image objects */
 /*
     libzint - the open source barcode library
-    Copyright (C) 2018-2025 Robin Stuart <rstuart114@gmail.com>
+    Copyright (C) 2018-2026 Robin Stuart <rstuart114@gmail.com>
 
     Redistribution and use in source and binary forms, with or without
     modification, are permitted provided that the following conditions
@@ -30,6 +30,8 @@
  */
 /* SPDX-License-Identifier: BSD-3-Clause */
 
+#include <assert.h>
+
 #include "common.h"
 #include "output.h"
 #include "zfiletypes.h"
@@ -42,6 +44,11 @@ static int vector_add_rect(struct zint_symbol *symbol, const float x, const floa
             const float height, struct zint_vector_rect **last_rect) {
     struct zint_vector_rect *rect;
 
+    assert(x >= 0.0f);
+    assert(y >= 0.0f);
+    assert(width >= 0.0f);
+    assert(height >= 0.0f);
+
     if (!(rect = (struct zint_vector_rect *) malloc(sizeof(struct zint_vector_rect)))) {
         /* NOTE: clang-tidy-20 gets confused about return value of function returning a function unfortunately,
            so put on 2 lines (see also "postal.c" `postnet_enc()` & `planet_enc()`, same issue) */
@@ -73,6 +80,10 @@ static int vector_add_hexagon(struct zint_symbol *symbol, const float x, const f
             const float diameter, struct zint_vector_hexagon **last_hexagon) {
     struct zint_vector_hexagon *hexagon;
 
+    assert(x >= 0.0f);
+    assert(y >= 0.0f);
+    assert(diameter >= 0.0f);
+
     if (!(hexagon = (struct zint_vector_hexagon *) malloc(sizeof(struct zint_vector_hexagon)))) {
         return z_errtxt(0, symbol, 692, "Insufficient memory for vector hexagon");
     }
@@ -99,6 +110,11 @@ static int vector_add_circle(struct zint_symbol *symbol, const float x, const fl
             const float width, const int colour, struct zint_vector_circle **last_circle) {
     struct zint_vector_circle *circle;
 
+    assert(x >= 0.0f);
+    assert(y >= 0.0f);
+    assert(diameter >= 0.0f);
+    assert(width >= 0.0f);
+
     if (!(circle = (struct zint_vector_circle *) malloc(sizeof(struct zint_vector_circle)))) {
         return z_errtxt(0, symbol, 693, "Insufficient memory for vector circle");
     }
@@ -127,6 +143,10 @@ static int vector_add_string(struct zint_symbol *symbol, const unsigned char *te
             struct zint_vector_string **last_string) {
     struct zint_vector_string *string;
 
+    assert(x >= -0.5f); /* May be slightly negative due to fudging */
+    assert(y >= 0.0f);
+    assert(width >= 0.0f);
+
     if (!(string = (struct zint_vector_string *) malloc(sizeof(struct zint_vector_string)))) {
         return z_errtxt(0, symbol, 694, "Insufficient memory for vector string");
     }
@@ -934,6 +954,7 @@ INTERNAL int zint_plot_vector(struct zint_symbol *symbol, int rotate_angle, int
             /* Avoid 11-module start and 13-module stop chars */
             sep_xoffset += 11;
             sep_width -= 11 + 13;
+            assert(sep_width >= 0.0f);
         }
         /* Adjust original rectangles so don't overlap with separator(s) (important for RGBA) */
         for (r = 0; r < symbol->rows; r++) {
@@ -952,7 +973,7 @@ INTERNAL int zint_plot_vector(struct zint_symbol *symbol, int rotate_angle, int
                 } else {
                     rect->height -= sep_half_height;
                 }
-                if (rect->height < 0) {
+                if (rect->height < 0.0f) {
                     rect->height = 0.0f;
                     /* TODO: warn? */
                 }
@@ -960,7 +981,8 @@ INTERNAL int zint_plot_vector(struct zint_symbol *symbol, int rotate_angle, int
         }
         for (r = 1; r < symbol->rows; r++) {
             const float row_height = symbol->row_height[r - 1] ? symbol->row_height[r - 1] : large_bar_height;
-            if (!vector_add_rect(symbol, sep_xoffset, (r * row_height) + sep_yoffset, sep_width, sep_height,
+            const float y = (r * row_height) + sep_yoffset;
+            if (!vector_add_rect(symbol, sep_xoffset, y < 0.0f ? 0.0f : y, sep_width, sep_height,
                     &last_rect)) return ZINT_ERROR_MEMORY;
         }
     }