Implemented typesetter to allow exact paging. Improved spacing between chars.

components/epaper/EPD.c

@@ -44,6 +44,7 @@ uint8_t   font_transparent;	// if not 0 draw fonts transparent
 uint8_t   font_forceFixed;  // if not zero force drawing proportional fonts with fixed width
 uint8_t   font_buffered_char;
 uint8_t   font_line_space;	// additional spacing between text lines; added to font height
+uint8_t	  font_x_space;		// additional spacing between characters in x axis
 uint8_t   text_wrap;        // if not 0 wrap long text to the new line, else clip
 color_t   _fg;            	// current foreground color for fonts
 color_t   _bg;            	// current background for non transparent fonts
@@ -1732,10 +1733,10 @@ int EPD_getStringWidth(char* str)
 		char* tempStrptr = str;
 		while (*tempStrptr != 0) {
 			if (getCharPtr(*tempStrptr++)) {
-				strWidth += (((fontChar.width > fontChar.xDelta) ? fontChar.width : fontChar.xDelta) + 1);
+				strWidth += (((fontChar.width > fontChar.xDelta) ? fontChar.width : fontChar.xDelta) + font_x_space);
 			}
 		}
-		strWidth--;
+		strWidth -= font_x_space;
 	}
 	return strWidth;
 }
@@ -1980,7 +1981,7 @@ void EPD_print(char *st, int x, int y) {
 			// Let's print the character
 			if (cfont.x_size == 0) {
 				// == proportional font
-				if (font_rotate == 0) EPD_X += printProportionalChar( EPD_X, EPD_Y) + 1;
+				if (font_rotate == 0) EPD_X += printProportionalChar( EPD_X, EPD_Y) + font_x_space;
 				else {
 					// rotated proportional font
 					offset += rotatePropChar(x, y, offset);

components/epaper/EPD.h

@@ -45,6 +45,7 @@ extern uint8_t   font_transparent;	// if not 0 draw fonts transparent
 extern uint8_t   font_forceFixed;  // if not zero force drawing proportional fonts with fixed width
 extern uint8_t   font_buffered_char;
 extern uint8_t   font_line_space;	// additional spacing between text lines; added to font height
+extern uint8_t	 font_x_space;		// additional spacing between characters in x axis
 extern uint8_t   text_wrap;        // if not 0 wrap long text to the new line, else clip
 extern color_t   _fg;            	// current foreground color for fonts
 extern color_t   _bg;            	// current background for non transparent fonts

main/Page.h

@@ -7,6 +7,7 @@ class Page
 public:
     Page();
 
+    size_t start;
     char* text;
     size_t len;
 

main/PagePrinter.cpp

@@ -5,7 +5,8 @@
 #include "esp_log.h"
 static const char *TAG = "PagePrinter";
 
-int font = DEJAVU18_FONT;//DEFAULT_FONT;
+//int pageFont = DEFAULT_FONT;
+int pageFont = DEJAVU18_FONT;
 
 PagePrinter::PagePrinter()
 {}
@@ -19,7 +20,7 @@ void PagePrinter::print(Page* page)
     if (page->len == 0) {
         return;
     }
-    EPD_setFont(font, NULL);
+    EPD_setFont(pageFont, NULL);
     text_wrap = 1;
     EPD_print(page->text, 0, 0);
     //EPD_UpdateScreen();

main/PagePrinter.h

@@ -6,6 +6,4 @@ public:
     PagePrinter();
 
     void print(Page* page);
-
-private:
 };

main/PageSettingsProvider.cpp

@@ -0,0 +1,48 @@
+#include "PageSettingsProvider.h"
+#include "EPD.h"
+#include "EPDspi.h" // TODO: remove after display config is extracted
+
+int PageSettingsProvider::getWidth()
+{
+    return EPD_DISPLAY_WIDTH;
+}
+
+int PageSettingsProvider::getHeight()
+{
+    return EPD_DISPLAY_HEIGHT;
+}
+
+int PageSettingsProvider::getCharWidth(char c)
+{
+    char txt[2] = { c, 0x00 };
+    return this->getStringWidth(txt);
+}
+
+extern int pageFont;
+void activatePageFont()
+{
+    EPD_setFont(pageFont, NULL); // TODO: hack to get the same font as the printer
+}
+
+int PageSettingsProvider::getStringWidth(char* string)
+{
+    activatePageFont();
+    int ret = EPD_getStringWidth(string);
+    return ret;
+}
+
+int PageSettingsProvider::getCharSpace()
+{
+    return font_x_space;
+}
+
+int PageSettingsProvider::getLineHeight()
+{
+    activatePageFont();
+    return EPD_getfontheight();
+}
+
+int PageSettingsProvider::getLineSpace()
+{
+    return font_line_space;
+}

main/PageSettingsProvider.h

@@ -0,0 +1,12 @@
+class PageSettingsProvider
+{
+public:
+    int getWidth();
+    int getHeight();
+
+    int getCharWidth(char c);
+    int getStringWidth(char* string);
+    int getCharSpace();
+    int getLineHeight();
+    int getLineSpace();
+};

main/TextReader.cpp

@@ -32,7 +32,7 @@ size_t TextReader::read(long pos, char* text, size_t len)
         fseek(this->f, pos, SEEK_SET);
         size_t read = fread(text, 1, len, this->f);
         if (read > 0) {
-            ESP_LOGI(TAG, "Read content: %s", text);
+            //ESP_LOGI(TAG, "Read content: %s", text);
         } else {
             ESP_LOGI(TAG, "End of file. Closing.");
             fclose(this->f);

main/Typesetter.cpp

@@ -1,27 +1,38 @@
 #include <string.h>
 #include "Typesetter.h"
 
+#include "esp_log.h"
+static const char *TAG = "Typesetter";
+
 Typesetter::Typesetter()
-{}
+{
+    this->pageSettingsProvider = new PageSettingsProvider(); // TODO: make it a param
+}
 
-Page* Typesetter::preparePage(char* text, size_t len)
+Typesetter::~Typesetter()
+{
+    delete this->pageSettingsProvider;
+}
+
+static Page* extractPage(char* text, size_t len)
 {
     Page* page = new Page;
     page->text = new char[len+1];
     memcpy(page->text, text, len);
     page->text[len] = 0;
     page->len = len;
+    ESP_LOGI(TAG, "Extracted page (%d bytes):\n%s\n----", page->len, page->text);
     return page;
 }
 
+Page* Typesetter::preparePage(char* text, size_t len)
+{
+    return this->preparePageInternal(text, len, 0);
+}
+
 Page* Typesetter::preparePreviousPage(char* text, size_t len)
 {
-    Page* page = new Page;
-    page->text = new char[len+1];
-    memcpy(page->text, text, len);
-    page->text[len] = 0;
-    page->len = len;
-    return page;
+    return this->preparePageInternal(text, len, 1);
 }
 
 void Typesetter::destroyPage(Page* page)
@@ -32,3 +43,40 @@ void Typesetter::destroyPage(Page* page)
     delete page->text;
     delete page;
 }
+
+Page* Typesetter::preparePageInternal(char* text, size_t len, int reverse)
+{
+    int page_width = this->pageSettingsProvider->getWidth();
+    int page_height = this->pageSettingsProvider->getHeight();
+    int line_height = this->pageSettingsProvider->getLineHeight()
+        + this->pageSettingsProvider->getLineSpace();
+    int line_count = page_height / line_height;
+
+    char buf[len+1];
+    memset(buf, 0, len+1);
+
+    int line_start = 0;
+    ESP_LOGI(TAG, " === Typesetting%s page === ", reverse ? " reversed" : "");
+    for (int line = 0; line < line_count && line_start < len; line++) {
+        int i;
+        for (i = line_start; i < len; i++) {
+            buf[i] = text[reverse ? (len - i) : (i)];
+            if (buf[i] == '\n') {
+                break;
+            }
+            int line_width = this->pageSettingsProvider->getStringWidth(&buf[line_start]);
+            if (line_width > page_width) {
+                // backtrack
+                buf[i] = 0;
+                i--;
+                break;
+            }
+        }
+        ESP_LOGI(TAG, "Line %d | %s", line, &buf[line_start]);
+        //ESP_LOGI(TAG, "Line %d [%04d:%04d] | %s | %03d / %03d", line, line_start, i, &buf[line_start],
+        //    this->pageSettingsProvider->getStringWidth(&buf[line_start]), page_width);
+        line_start = i + 1;
+    }
+
+    return extractPage(text, line_start);
+}

main/Typesetter.h

@@ -1,12 +1,20 @@
 #include <stdlib.h>
 #include "Page.h"
+#include "PageSettingsProvider.h"
 
 class Typesetter
 {
 public:
     Typesetter();
+    ~Typesetter();
 
     Page* preparePage(char* text, size_t len);
     Page* preparePreviousPage(char* text, size_t len);
     void destroyPage(Page* page);
+
+private:
+    Page* preparePageInternal(char* text, size_t len, int direction);
+
+    PageSettingsProvider* pageSettingsProvider; // TODO: expose so it may be changed
 };
+

main/main.cpp

@@ -70,11 +70,20 @@ extern "C" void app_main()
         if (textReader != NULL) {
             if (pageCurrent == NULL) {
                 size_t read = textReader->read(bookmark, text, sizeof(text));
-                pageCurrent = typesetter.preparePage(text, sizeof(text));
+                pageCurrent = typesetter.preparePage(text, read);
+                pageCurrent->start = bookmark;
             }
             if (pageLast == NULL) {
-                size_t read = textReader->read(bookmark - sizeof(text), text, sizeof(text));
-                pageLast = typesetter.preparePreviousPage(text, sizeof(text));
+                // align with the start?
+                if (bookmark < sizeof(text)) {
+                    size_t read = textReader->read(0, text, sizeof(text));
+                    pageLast = typesetter.preparePage(text, read);
+                    pageLast->start = 0;
+                } else {
+                    size_t read = textReader->read((bookmark - sizeof(text)), text, sizeof(text));
+                    pageLast = typesetter.preparePreviousPage(text, read);
+                    pageLast->start = bookmark - pageLast->len;
+                }
             }
         } else {
             typesetter.destroyPage(pageCurrent);
@@ -97,7 +106,8 @@ extern "C" void app_main()
             if (buttons_pressed_plus()) {
                 ESP_LOGI(TAG, "Turn page PLUS.");
                 if (pageCurrent != NULL) {
-                    bookmark += pageCurrent->len;
+                    bookmark = pageCurrent->start + pageCurrent->len;
+                    // TODO: limit bookmark to file size
                     typesetter.destroyPage(pageLast);
                     pageLast = pageCurrent;
                     pageCurrent = NULL;
@@ -109,7 +119,7 @@ extern "C" void app_main()
             if (buttons_pressed_minus()) {
                 ESP_LOGI(TAG, "Turn page MINUS.");
                 if (pageLast != NULL) {
-                    bookmark -= pageLast->len;
+                    bookmark = pageLast->start;
                     typesetter.destroyPage(pageCurrent);
                     pageCurrent = pageLast;
                     pageLast = NULL;