Fix compiler warnings [-Wmissing-prototypes]

Add missing include statements, add missing "static" qualifiers or
remove functions which are not used at all.

Signed-off-by: Stefan Weil <sw@weilnetz.de>

src/api/baseapi.cpp

@@ -2622,9 +2622,9 @@ void TessBaseAPI::NormalizeTBLOB(TBLOB *tblob, ROW *row, bool numeric_mode) {
  * Return a TBLOB * from the whole pix.
  * To be freed later with delete.
  */
-TBLOB *make_tesseract_blob(float baseline, float xheight,
-                           float descender, float ascender,
-                           bool numeric_mode, Pix* pix) {
+static TBLOB *make_tesseract_blob(float baseline, float xheight,
+                                  float descender, float ascender,
+                                  bool numeric_mode, Pix* pix) {
   TBLOB *tblob = TessBaseAPI::MakeTBLOB(pix);
 
   // Normalize TBLOB

src/api/pdfrenderer.cpp

@@ -202,15 +202,15 @@ void TessPDFRenderer::AppendPDFObject(const char *data) {
 // Helper function to prevent us from accidentally writing
 // scientific notation to an HOCR or PDF file. Besides, three
 // decimal points are all you really need.
-double prec(double x) {
+static double prec(double x) {
   double kPrecision = 1000.0;
   double a = round(x * kPrecision) / kPrecision;
   if (a == -0)
     return 0;
   return a;
 }
 
-long dist2(int x1, int y1, int x2, int y2) {
+static long dist2(int x1, int y1, int x2, int y2) {
   return (x2 - x1) * (x2 - x1) + (y2 - y1) * (y2 - y1);
 }
 
@@ -222,10 +222,10 @@ long dist2(int x1, int y1, int x2, int y2) {
 // left-to-right no matter what the reading order is. We need the
 // word baseline in reading order, so we do that conversion here. Returns
 // the word's baseline origin and length.
-void GetWordBaseline(int writing_direction, int ppi, int height,
-                     int word_x1, int word_y1, int word_x2, int word_y2,
-                     int line_x1, int line_y1, int line_x2, int line_y2,
-                     double *x0, double *y0, double *length) {
+static void GetWordBaseline(int writing_direction, int ppi, int height,
+                            int word_x1, int word_y1, int word_x2, int word_y2,
+                            int line_x1, int line_y1, int line_x2, int line_y2,
+                            double *x0, double *y0, double *length) {
   if (writing_direction == WRITING_DIRECTION_RIGHT_TO_LEFT) {
     Swap(&word_x1, &word_x2);
     Swap(&word_y1, &word_y2);
@@ -264,9 +264,9 @@ void GetWordBaseline(int writing_direction, int ppi, int height,
 //                           RTL
 // [ x' ] = [ a b ][ x ] = [-1 0 ] [ cos sin ][ x ]
 // [ y' ]   [ c d ][ y ]   [ 0 1 ] [-sin cos ][ y ]
-void AffineMatrix(int writing_direction,
-                  int line_x1, int line_y1, int line_x2, int line_y2,
-                  double *a, double *b, double *c, double *d) {
+static void AffineMatrix(int writing_direction,
+                         int line_x1, int line_y1, int line_x2, int line_y2,
+                         double *a, double *b, double *c, double *d) {
   double theta = atan2(static_cast<double>(line_y1 - line_y2),
                        static_cast<double>(line_x2 - line_x1));
   *a = cos(theta);

src/ccmain/osdetect.cpp

@@ -156,8 +156,9 @@ void OSResults::accumulate(const OSResults& osr) {
 
 // Detect and erase horizontal/vertical lines and picture regions from the
 // image, so that non-text blobs are removed from consideration.
-void remove_nontext_regions(tesseract::Tesseract *tess, BLOCK_LIST *blocks,
-                            TO_BLOCK_LIST *to_blocks) {
+static void remove_nontext_regions(tesseract::Tesseract *tess,
+                                   BLOCK_LIST *blocks,
+                                   TO_BLOCK_LIST *to_blocks) {
   Pix *pix = tess->pix_binary();
   ASSERT_HOST(pix != nullptr);
   int vertical_x = 0;

src/ccmain/output.cpp

@@ -42,23 +42,6 @@
 #define CTRL_NEWLINE      '\012' //newline
 #define CTRL_HARDLINE   '\015'   //cr
 
-/**********************************************************************
- * pixels_to_pts
- *
- * Convert an integer number of pixels to the nearest integer
- * number of points.
- **********************************************************************/
-
-int32_t pixels_to_pts(               //convert coords
-                    int32_t pixels,
-                    int32_t pix_res  //resolution
-                   ) {
-  float pts;                     //converted value
-
-  pts = pixels * 72.0 / pix_res;
-  return (int32_t) (pts + 0.5);    //round it
-}
-
 namespace tesseract {
 void Tesseract::output_pass(  //Tess output pass //send to api
                             PAGE_RES_IT &page_res_it,