Squash some warnings in MSVC build.

In particular, "defined but not used" (caused by GRAPHICS_DISABLED),
double constants being truncated to floats, and implicit casts.

src/ccmain/control.cpp

@@ -74,9 +74,6 @@ void Tesseract::recog_pseudo_word(PAGE_RES* page_res,
  * @param pr_it the page results iterator
  */
 bool Tesseract::recog_interactive(PAGE_RES_IT* pr_it) {
-  int16_t char_qual;
-  int16_t good_char_qual;
-
   WordData word_data(*pr_it);
   SetupWordPassN(2, &word_data);
   // LSTM doesn't run on pass2, but we want to run pass2 for tesseract.
@@ -89,6 +86,8 @@ bool Tesseract::recog_interactive(PAGE_RES_IT* pr_it) {
   }
 #ifndef DISABLED_LEGACY_ENGINE
   if (tessedit_debug_quality_metrics) {
+    int16_t char_qual;
+    int16_t good_char_qual;
     WERD_RES* word_res = pr_it->word();
     word_char_quality(word_res, &char_qual, &good_char_qual);
     tprintf("\n%d chars;  word_blob_quality: %d;  outline_errs: %d; "

src/ccstruct/points.h

@@ -71,7 +71,7 @@ class ICOORD
 
     ///find sq length
     float sqlength() const {
-      return xcoord * xcoord + ycoord * ycoord;
+      return (float)(xcoord * xcoord + ycoord * ycoord);
     }
 
     ///find length
@@ -95,7 +95,7 @@ class ICOORD
 
     ///find angle
     float angle() const {
-      return std::atan2(ycoord, xcoord);
+      return (float)std::atan2(ycoord, xcoord);
     }
 
     ///test equality

src/ccstruct/ratngs.cpp

@@ -456,7 +456,7 @@ void WERD_CHOICE::string_and_lengths(STRING *word_str,
     const char *ch = unicharset_->id_to_unichar_ext(unichar_ids_[i]);
     *word_str += ch;
     if (word_lengths_str != nullptr) {
-      *word_lengths_str += strlen(ch);
+      *word_lengths_str += (char)strlen(ch);
     }
   }
 }

src/textord/cjkpitch.cpp

@@ -32,11 +32,11 @@ static BOOL_VAR(textord_space_size_is_variable, false,
 namespace {
 
 // Allow +/-10% error for character pitch / body size.
-static const float kFPTolerance = 0.1;
+static const float kFPTolerance = 0.1f;
 
 // Minimum ratio of "good" character pitch for a row to be considered
 // to be fixed-pitch.
-static const float kFixedPitchThreshold = 0.35;
+static const float kFixedPitchThreshold = 0.35f;
 
 // rank statistics for a small collection of float values.
 class SimpleStats {
@@ -1020,7 +1020,7 @@ void FPAnalyzer::EstimatePitch(bool pass1) {
     } else if (row.num_chars() > 1) {
       float estimated_pitch =
           pitch_height_stats.EstimateYFor(row.height() + row.gap(),
-                                          0.1);
+                                          0.1f);
       // CJK characters are more likely to be fragmented than poorly
       // chopped. So trust the page-level estimation of character
       // pitch only if it's larger than row-level estimation or

src/textord/oldbasel.cpp

@@ -583,7 +583,7 @@ float jumplimit                  /*guess half descenders */
         }
       }
 
-      jumplimit *= 1.2;
+      jumplimit *= 1.2f;
                                  /*must be wavy */
       if (maxmax - minmin > jumplimit) {
         ycount = segment;        /*no of segments */

src/textord/topitch.cpp

@@ -417,10 +417,8 @@ bool try_doc_fixed(                             //determine pitch
   int16_t projection_right;
   int16_t row_left;                //edges of row
   int16_t row_right;
-  ICOORDELT_LIST *master_cells;  //cells for page
   float master_y;                //uniform shifts
   float shift_factor;            //page skew correction
-  float row_shift;               //shift for row
   float final_pitch;             //output pitch
   float row_y;                   //baseline
   STATS projection;              //entire page
@@ -512,13 +510,15 @@ bool try_doc_fixed(                             //determine pitch
 
 #ifndef GRAPHICS_DISABLED
   if (textord_show_page_cuts && to_win != nullptr) {
+    float row_shift;               //shift for row
+    ICOORDELT_LIST *master_cells;  //cells for page
     master_cells = &row->char_cells;
     for (block_it.mark_cycle_pt (); !block_it.cycled_list ();
     block_it.forward ()) {
       block = block_it.data ();
       row_it.set_to_list (block->get_rows ());
       for (row_it.mark_cycle_pt (); !row_it.cycled_list ();
-      row_it.forward ()) {
+           row_it.forward ()) {
         row = row_it.data ();
         row_y = row->baseline.y (master_x);
         row_shift = shift_factor * (master_y - row_y);
@@ -871,7 +871,7 @@ bool find_row_pitch(                    //find lines
 
   if (!count_pitch_stats (row, &gap_stats, &pitch_stats,
   initial_pitch, min_space, true, false, dm_gap)) {
-    dm_gap_iqr = 0.0001;
+    dm_gap_iqr = 0.0001f;
     dm_pitch_iqr = maxwidth * 2.0f;
     dm_pitch = initial_pitch;
   }
@@ -884,7 +884,7 @@ bool find_row_pitch(                    //find lines
   pitch_stats.clear ();
   if (!count_pitch_stats (row, &gap_stats, &pitch_stats,
   initial_pitch, min_space, true, false, 0)) {
-    gap_iqr = 0.0001;
+    gap_iqr = 0.0001f;
     pitch_iqr = maxwidth * 3.0f;
   }
   else {