Added support for rotated text (#133)

* Added support for rotated text - this necessitates the addition of `-lm` for sinf/cosf support.

.github/workflows/build_and_test.yml

@@ -16,7 +16,7 @@ jobs:
           make CC=/usr/lib/mxe/usr/bin/i686-w64-mingw32.static-gcc CLANG_FORMAT=clang-format-10
           cp testprog testprog.exe
       - name: Infer
-        run: make clean && infer run --no-progress-bar -- make CFLAGS="-g -Wall -pipe" LFLAGS=""
+        run: make clean && infer run --no-progress-bar -- make CFLAGS="-g -Wall -pipe" LFLAGS="-lm"
       - name: Build
         run: make clean && make
       - name: Update coverage statistics

Makefile

@@ -1,4 +1,4 @@
-LFLAGS=-fprofile-arcs -ftest-coverage
+LFLAGS=-fprofile-arcs -ftest-coverage -lm
 CLANG=clang
 CLANG_FORMAT=clang-format
 XXD=xxd

README.md

@@ -10,7 +10,7 @@ All contained a single C-file with header and no external library dependencies.
 Useful for embedding into other programs that require rudimentary PDF output.
 
 Supports the following PDF features
-* Text of various fonts/sizes/colours
+* Text of various fonts/sizes/colours/rotation
 * Primitive drawing elements
     * Lines
     * Rectangles

pdfgen.c

@@ -3,7 +3,7 @@
  * It supports text, shapes, images etc...
  * Capable of handling millions of objects without too much performance
  * penalty.
- * Public domain license - no warrenty implied; use at your own risk.
+ * Public domain license - no warranty implied; use at your own risk.
  */
 
 /**
@@ -1374,7 +1374,7 @@ static int utf8_to_pdfencoding(struct pdf_doc *pdf, const char *utf8, int len,
     if (code > 255) {
         /* We support *some* minimal UTF-8 characters */
         // See Appendix D of
-        // https://www.adobe.com/content/dam/acom/en/devnet/pdf/pdfs/pdf_reference_archives/PDFReference.pdf
+        // https://opensource.adobe.com/dc-acrobat-sdk-docs/pdfstandards/pdfreference1.7old.pdf
         // These are all in WinAnsiEncoding
         switch (code) {
         case 0x160: // Latin Capital Letter S with Caron
@@ -1409,8 +1409,8 @@ static int utf8_to_pdfencoding(struct pdf_doc *pdf, const char *utf8, int len,
             break;
         default:
             return pdf_set_err(pdf, -EINVAL,
-                               "Unsupported UTF-8 character: 0x%x 0o%o", code,
-                               code);
+                               "Unsupported UTF-8 character: 0x%x 0o%o %s",
+                               code, code, utf8);
         }
     } else {
         *res = code;
@@ -1420,7 +1420,8 @@ static int utf8_to_pdfencoding(struct pdf_doc *pdf, const char *utf8, int len,
 
 static int pdf_add_text_spacing(struct pdf_doc *pdf, struct pdf_object *page,
                                 const char *text, float size, float xoff,
-                                float yoff, uint32_t colour, float spacing)
+                                float yoff, uint32_t colour, float spacing,
+                                float angle)
 {
     int ret;
     size_t len = text ? strlen(text) : 0;
@@ -1433,7 +1434,12 @@ static int pdf_add_text_spacing(struct pdf_doc *pdf, struct pdf_object *page,
 
     dstr_append(&str, "BT ");
     dstr_printf(&str, "/GS%d gs ", alpha);
-    dstr_printf(&str, "%f %f TD ", xoff, yoff);
+    if (angle != 0) {
+        dstr_printf(&str, "%f %f %f %f %f %f Tm ", cosf(angle), sinf(angle),
+                    -sinf(angle), cosf(angle), xoff, yoff);
+    } else {
+        dstr_printf(&str, "%f %f TD ", xoff, yoff);
+    }
     dstr_printf(&str, "/F%d %f Tf ", pdf->current_font->font.index, size);
     dstr_printf(&str, "%f %f %f rg ", PDF_RGB_R(colour), PDF_RGB_G(colour),
                 PDF_RGB_B(colour));
@@ -1478,7 +1484,16 @@ int pdf_add_text(struct pdf_doc *pdf, struct pdf_object *page,
                  const char *text, float size, float xoff, float yoff,
                  uint32_t colour)
 {
-    return pdf_add_text_spacing(pdf, page, text, size, xoff, yoff, colour, 0);
+    return pdf_add_text_spacing(pdf, page, text, size, xoff, yoff, colour, 0,
+                                0);
+}
+
+int pdf_add_text_rotate(struct pdf_doc *pdf, struct pdf_object *page,
+                        const char *text, float size, float xoff, float yoff,
+                        float angle, uint32_t colour)
+{
+    return pdf_add_text_spacing(pdf, page, text, size, xoff, yoff, colour, 0,
+                                angle);
 }
 
 /* How wide is each character, in points, at size 14 */
@@ -1812,8 +1827,8 @@ static const char *find_word_break(const char *string)
 
 int pdf_add_text_wrap(struct pdf_doc *pdf, struct pdf_object *page,
                       const char *text, float size, float xoff, float yoff,
-                      uint32_t colour, float wrap_width, int align,
-                      float *height)
+                      float angle, uint32_t colour, float wrap_width,
+                      int align, float *height)
 {
     /* Move through the text string, stopping at word boundaries,
      * trying to find the longest text string we can fit in the given width
@@ -1913,7 +1928,7 @@ int pdf_add_text_wrap(struct pdf_doc *pdf, struct pdf_object *page,
 
             if (align != PDF_ALIGN_NO_WRITE) {
                 pdf_add_text_spacing(pdf, page, line, size, xoff_align, yoff,
-                                     colour, char_spacing);
+                                     colour, char_spacing, angle);
             }
 
             if (*end == ' ')
@@ -1985,7 +2000,7 @@ int pdf_add_quadratic_bezier(struct pdf_doc *pdf, struct pdf_object *page,
 }
 
 int pdf_add_custom_path(struct pdf_doc *pdf, struct pdf_object *page,
-                        struct pdf_path_operation *operations,
+                        const struct pdf_path_operation *operations,
                         int operation_count, float stroke_width,
                         uint32_t stroke_colour, uint32_t fill_colour)
 {
@@ -2632,7 +2647,7 @@ static int pdf_add_barcode_ean13(struct pdf_doc *pdf, struct pdf_object *page,
 
     for (int i = 0; i != 6; i++) {
         text[0] = *string;
-        e = pdf_add_text_wrap(pdf, page, text, font, x, y, colour,
+        e = pdf_add_text_wrap(pdf, page, text, font, x, y, 0, colour,
                               7 * x_width, PDF_ALIGN_CENTER, NULL);
         if (e < 0) {
             pdf_set_font(pdf, save_font);
@@ -2659,7 +2674,7 @@ static int pdf_add_barcode_ean13(struct pdf_doc *pdf, struct pdf_object *page,
 
     for (int i = 0; i != 6; i++) {
         text[0] = *string;
-        e = pdf_add_text_wrap(pdf, page, text, font, x, y, colour,
+        e = pdf_add_text_wrap(pdf, page, text, font, x, y, 0, colour,
                               7 * x_width, PDF_ALIGN_CENTER, NULL);
         if (e < 0) {
             pdf_set_font(pdf, save_font);
@@ -2746,7 +2761,7 @@ static int pdf_add_barcode_upca(struct pdf_doc *pdf, struct pdf_object *page,
     for (int i = 0; i != 6; i++) {
         text[0] = *string;
         if (i) {
-            e = pdf_add_text_wrap(pdf, page, text, font, x, y, colour,
+            e = pdf_add_text_wrap(pdf, page, text, font, x, y, 0, colour,
                                   7 * x_width, PDF_ALIGN_CENTER, NULL);
             if (e < 0) {
                 pdf_set_font(pdf, save_font);
@@ -2775,7 +2790,7 @@ static int pdf_add_barcode_upca(struct pdf_doc *pdf, struct pdf_object *page,
     for (int i = 0; i != 6; i++) {
         text[0] = *string;
         if (i != 5) {
-            e = pdf_add_text_wrap(pdf, page, text, font, x, y, colour,
+            e = pdf_add_text_wrap(pdf, page, text, font, x, y, 0, colour,
                                   7 * x_width, PDF_ALIGN_CENTER, NULL);
             if (e < 0) {
                 pdf_set_font(pdf, save_font);
@@ -2864,7 +2879,7 @@ static int pdf_add_barcode_ean8(struct pdf_doc *pdf, struct pdf_object *page,
 
     for (int i = 0; i != 4; i++) {
         text[0] = *string;
-        e = pdf_add_text_wrap(pdf, page, text, font, x, y, colour,
+        e = pdf_add_text_wrap(pdf, page, text, font, x, y, 0, colour,
                               7 * x_width, PDF_ALIGN_CENTER, NULL);
         if (e < 0) {
             pdf_set_font(pdf, save_font);
@@ -2890,7 +2905,7 @@ static int pdf_add_barcode_ean8(struct pdf_doc *pdf, struct pdf_object *page,
 
     for (int i = 0; i != 4; i++) {
         text[0] = *string;
-        e = pdf_add_text_wrap(pdf, page, text, font, x, y, colour,
+        e = pdf_add_text_wrap(pdf, page, text, font, x, y, 0, colour,
                               7 * x_width, PDF_ALIGN_CENTER, NULL);
         if (e < 0) {
             pdf_set_font(pdf, save_font);
@@ -3013,7 +3028,7 @@ static int pdf_add_barcode_upce(struct pdf_doc *pdf, struct pdf_object *page,
 
     for (int i = 0; i != 6; i++) {
         text[0] = X[i];
-        e = pdf_add_text_wrap(pdf, page, text, font, x, y, colour,
+        e = pdf_add_text_wrap(pdf, page, text, font, x, y, 0, colour,
                               7 * x_width, PDF_ALIGN_CENTER, NULL);
         if (e < 0) {
             pdf_set_font(pdf, save_font);

pdfgen.h

@@ -425,6 +425,21 @@ int pdf_add_text(struct pdf_doc *pdf, struct pdf_object *page,
                  const char *text, float size, float xoff, float yoff,
                  uint32_t colour);
 
+/**
+ * Add a text string to the document at a rotated angle
+ * @param pdf PDF document to add to
+ * @param page Page to add object to (NULL => most recently added page)
+ * @param text String to display
+ * @param size Point size of the font
+ * @param xoff X location to put it in
+ * @param yoff Y location to put it in
+ * @param angle Rotation angle of text (in radians)
+ * @param colour Colour to draw the text
+ * @return 0 on success, < 0 on failure
+ */
+int pdf_add_text_rotate(struct pdf_doc *pdf, struct pdf_object *page,
+                        const char *text, float size, float xoff, float yoff,
+                        float angle, uint32_t colour);
 /**
  * Add a text string to the document, making it wrap if it is too
  * long
@@ -434,6 +449,7 @@ int pdf_add_text(struct pdf_doc *pdf, struct pdf_object *page,
  * @param size Point size of the font
  * @param xoff X location to put it in
  * @param yoff Y location to put it in
+ * @param angle Rotation angle of text (in radians)
  * @param colour Colour to draw the text
  * @param wrap_width Width at which to wrap the text
  * @param align Text alignment (see PDF_ALIGN_xxx)
@@ -442,8 +458,8 @@ int pdf_add_text(struct pdf_doc *pdf, struct pdf_object *page,
  */
 int pdf_add_text_wrap(struct pdf_doc *pdf, struct pdf_object *page,
                       const char *text, float size, float xoff, float yoff,
-                      uint32_t colour, float wrap_width, int align,
-                      float *height);
+                      float angle, uint32_t colour, float wrap_width,
+                      int align, float *height);
 
 /**
  * Add a line to the document
@@ -512,7 +528,7 @@ int pdf_add_quadratic_bezier(struct pdf_doc *pdf, struct pdf_object *page,
  * @return 0 on success, < 0 on failure
  */
 int pdf_add_custom_path(struct pdf_doc *pdf, struct pdf_object *page,
-                        struct pdf_path_operation *operations,
+                        const struct pdf_path_operation *operations,
                         int operation_count, float stroke_width,
                         uint32_t stroke_colour, uint32_t fill_colour);
 

tests/fuzz-text.c

@@ -14,8 +14,8 @@ int LLVMFuzzerTestOneInput(char *data, int size)
     memcpy(text, data, size);
     text[size] = '\0';
     pdf_add_text(pdf, NULL, text, 10, 20, 30, PDF_RGB(0xff, 0, 0));
-    pdf_add_text_wrap(pdf, NULL, text, 10, 20, 30, PDF_RGB(0xff, 0, 0), 200,
-                      PDF_ALIGN_LEFT, NULL);
+    pdf_add_text_wrap(pdf, NULL, text, 10, 20, 30, 0, PDF_RGB(0xff, 0, 0),
+                      200, PDF_ALIGN_LEFT, NULL);
     free(text);
     pdf_save(pdf, "fuzz.pdf");
     pdf_destroy(pdf);

tests/main.c

@@ -1,7 +1,12 @@
 #include <locale.h>
+#include <math.h>
 #include <stdio.h>
 #include <string.h>
 
+#ifndef M_PI
+#define M_PI 3.14159265358979323846
+#endif
+
 #include "pdfgen.h"
 
 extern unsigned char data_penguin_jpg[];
@@ -89,7 +94,7 @@ int main(int argc, char *argv[])
         "And special stuff €ÜŽžŠšÁ that áüöä should ÄÜÖß— “”‘’ break\n"
         "————————————————————————————————————————————————\n"
         "thisisanenourmouswordthatwillneverfitandwillhavetobecut",
-        16, 60, 800, PDF_RGB(0, 0, 0), 300, PDF_ALIGN_JUSTIFY, &height);
+        16, 60, 800, 0, PDF_RGB(0, 0, 0), 300, PDF_ALIGN_JUSTIFY, &height);
     pdf_add_rectangle(pdf, NULL, 58, 800 + 16, 304, -height, 2,
                       PDF_RGB(0, 0, 0));
     pdf_add_image_file(pdf, NULL, 10, 10, 20, 30, "data/teapot.ppm");
@@ -135,8 +140,9 @@ int main(int argc, char *argv[])
     pdf_add_rectangle(pdf, NULL, 150, 150, 100, 100, 4, PDF_RGB(0, 0, 0xff));
     pdf_add_filled_rectangle(pdf, NULL, 150, 450, 100, 100, 4,
                              PDF_RGB(0, 0xff, 0), PDF_TRANSPARENT);
-    pdf_add_text(pdf, NULL, "This should be transparent", 20, 160, 500,
-                 PDF_ARGB(0x80, 0, 0, 0));
+    pdf_add_text_rotate(pdf, NULL, "This should be transparent", 20, 160, 500,
+                        M_PI / 4, PDF_ARGB(0x80, 0, 0, 0));
+
     float p1X[] = {200, 200, 300, 300};
     float p1Y[] = {200, 300, 200, 300};
     pdf_add_polygon(pdf, NULL, p1X, p1Y, 4, 4, PDF_RGB(0xaa, 0xff, 0xee));
@@ -158,7 +164,7 @@ int main(int argc, char *argv[])
         pdf, NULL,
         "Control characters ( ) < > [ ] { } / % \n \r \t \b \f ending", 10,
         50, 45, PDF_RGB(0, 0, 0));
-    pdf_add_text(pdf, NULL, "Special characters: €ÜŽžŠšÁáüöäÄÜÖß—“”‘’", 10,
+    pdf_add_text(pdf, NULL, "Special characters: €ÜŽžŠšÁáüöäÄÜÖß—“”‘’Æ", 10,
                  50, 15, PDF_RGB(0, 0, 0));
     pdf_add_text(pdf, NULL, "This one has a new line in it\nThere it was", 10,
                  50, 80, PDF_RGB(0, 0, 0));
@@ -226,7 +232,7 @@ int main(int argc, char *argv[])
                     PDF_MM_TO_POINT(20), "Code128", PDF_RGB(0, 0, 0));
 
     pdf_add_text_wrap(pdf, NULL, "EAN13 Barcode", 10, PDF_MM_TO_POINT(20),
-                      PDF_MM_TO_POINT(155), PDF_RGB(0, 0, 0),
+                      PDF_MM_TO_POINT(155), 0, PDF_RGB(0, 0, 0),
                       PDF_MM_TO_POINT(60), PDF_ALIGN_CENTER, NULL);
     pdf_add_rectangle(pdf, NULL, PDF_MM_TO_POINT(20), PDF_MM_TO_POINT(160),
                       PDF_MM_TO_POINT(60), PDF_MM_TO_POINT(40), 1,
@@ -235,7 +241,7 @@ int main(int argc, char *argv[])
                     PDF_MM_TO_POINT(160), PDF_MM_TO_POINT(60),
                     PDF_MM_TO_POINT(40), "4003994155486", PDF_BLACK);
     pdf_add_text_wrap(pdf, NULL, "UPCA Barcode", 10, PDF_MM_TO_POINT(100),
-                      PDF_MM_TO_POINT(155), PDF_RGB(0, 0, 0),
+                      PDF_MM_TO_POINT(155), 0, PDF_RGB(0, 0, 0),
                       PDF_MM_TO_POINT(60), PDF_ALIGN_CENTER, NULL);
     pdf_add_rectangle(pdf, NULL, PDF_MM_TO_POINT(100), PDF_MM_TO_POINT(160),
                       PDF_MM_TO_POINT(60), PDF_MM_TO_POINT(80), 1,
@@ -245,7 +251,7 @@ int main(int argc, char *argv[])
                     PDF_MM_TO_POINT(80), "003994155480", PDF_BLACK);
 
     pdf_add_text_wrap(pdf, NULL, "EAN8 Barcode", 10, PDF_MM_TO_POINT(20),
-                      PDF_MM_TO_POINT(55), PDF_RGB(0, 0, 0),
+                      PDF_MM_TO_POINT(55), 0, PDF_RGB(0, 0, 0),
                       PDF_MM_TO_POINT(60), PDF_ALIGN_CENTER, NULL);
     pdf_add_rectangle(pdf, NULL, PDF_MM_TO_POINT(20), PDF_MM_TO_POINT(60),
                       PDF_MM_TO_POINT(60), PDF_MM_TO_POINT(40), 1,
@@ -254,7 +260,7 @@ int main(int argc, char *argv[])
                     PDF_MM_TO_POINT(60), PDF_MM_TO_POINT(60),
                     PDF_MM_TO_POINT(40), "95012346", PDF_BLACK);
     pdf_add_text_wrap(pdf, NULL, "UPCE Barcode", 10, PDF_MM_TO_POINT(100),
-                      PDF_MM_TO_POINT(55), PDF_RGB(0, 0, 0),
+                      PDF_MM_TO_POINT(55), 0, PDF_RGB(0, 0, 0),
                       PDF_MM_TO_POINT(60), PDF_ALIGN_CENTER, NULL);
     pdf_add_rectangle(pdf, NULL, PDF_MM_TO_POINT(100), PDF_MM_TO_POINT(60),
                       PDF_MM_TO_POINT(60), PDF_MM_TO_POINT(80), 1,