Revision 142:6e9bff59878a, committed 2017-03-19

Comitter:

WiredHome

Date:

Sun Mar 19 21:41:24 2017 +0000

Parent:

141:2ec78a50dc98

Child:

143:e872d65a710d

Commit message:

Breaking change on SelectDrawingLayer command, which now returns the previous layer (making it far easier to restore layers).

Changed in this revision

--- a/GraphicsDisplay.cpp	Thu Dec 29 20:06:00 2016 +0000
+++ b/GraphicsDisplay.cpp	Sun Mar 19 21:41:24 2017 +0000
@@ -150,7 +150,17 @@
 
 RetCode_t GraphicsDisplay::cls(uint16_t layers)
 {
-    return fill(0, 0, width(), height(), _background);
+    int restore = GetDrawingLayer();
+    if (layers & 1) {
+        SelectDrawingLayer(0);
+        fill(0, 0, width(), height(), _background);
+    }
+    if (layers & 2) {
+        SelectDrawingLayer(1);
+        fill(0, 0, width(), height(), _background);
+    }
+    SelectDrawingLayer(restore);
+    return noerror;
 }
 
 RetCode_t GraphicsDisplay::blit(loc_t x, loc_t y, dim_t w, dim_t h, const int * color)

--- a/GraphicsDisplay.h	Thu Dec 29 20:06:00 2016 +0000
+++ b/GraphicsDisplay.h	Sun Mar 19 21:41:24 2017 +0000
@@ -147,6 +147,54 @@
     virtual RetCode_t fillrect(loc_t x1, loc_t y1, loc_t x2, loc_t y2, 
         color_t color, fill_t fillit = FILL) = 0;
 
+    /// Select the drawing layer for subsequent commands.
+    ///
+    /// If the screen configuration is 480 x 272, or if it is 800 x 480 
+    /// and 8-bit color, the the display supports two layers, which can 
+    /// be independently drawn on and shown. Additionally, complex
+    /// operations involving both layers are permitted.
+    ///
+    /// @code
+    ///     //lcd.SetLayerMode(OnlyLayer0); // default is layer 0
+    ///     lcd.rect(400,130, 475,155,Brown);
+    ///     lcd.SelectDrawingLayer(1);
+    ///     lcd.circle(400,25, 25, BrightRed);
+    ///     wait(1);
+    ///     lcd.SetLayerMode(ShowLayer1);
+    /// @endcode
+    ///
+    /// @attention The user manual refers to Layer 1 and Layer 2, however the
+    ///     actual register values are value 0 and 1. This API as well as
+    ///     others that reference the layers use the values 0 and 1 for
+    ///     cleaner iteration in the code.
+    ///
+    /// @param[in] layer is 0 or 1 to select the layer for subsequent 
+    ///     commands.
+    /// @returns the previous drawing layer; 0 or 1.
+    ///
+    virtual uint16_t SelectDrawingLayer(uint16_t layer) = 0;
+ 
+    
+    /// Get the currently active drawing layer.
+    ///
+    /// This returns a value, 0 or 1, based on the screen configuration
+    /// and the currently active drawing layer.
+    ///
+    /// @code
+    ///     uint16_t prevLayer = lcd.SelectDrawingLayer(x);
+    ///     lcd.circle(400,25, 25, BrightRed);
+    ///     lcd.SelectDrawingLayer(prevLayer);
+    /// @endcode
+    ///
+    /// @attention The user manual refers to Layer 1 and Layer 2, however the
+    ///     actual register values are value 0 and 1. This API as well as
+    ///     others that reference the layers use the values 0 and 1 for
+    ///     cleaner iteration in the code.
+    ///
+    /// @returns the current drawing layer; 0 or 1.
+    /// 
+    virtual uint16_t GetDrawingLayer(void) = 0;
+
     /// a function to write the command and data to the RA8875 chip.
     ///
     /// @param command is the RA8875 instruction to perform

--- a/RA8875.cpp	Thu Dec 29 20:06:00 2016 +0000
+++ b/RA8875.cpp	Sun Mar 19 21:41:24 2017 +0000
@@ -281,17 +281,19 @@
 }
 
 
-RetCode_t RA8875::SelectDrawingLayer(uint16_t layer)
+uint16_t RA8875::SelectDrawingLayer(uint16_t layer)
 {
-    unsigned char mwcr1 = ReadCommand(0x41) & ~0x01; // retain all but the currently selected layer
-
+    unsigned char mwcr1 = ReadCommand(0x41); // retain all but the currently selected layer
+    uint16_t prevlayer = mwcr1 & 1;
+    
+    mwcr1 &= ~0x01; // remove the current layer
     if (screenwidth >= 800 && screenheight >= 480 && screenbpp > 8) {
-        return bad_parameter;
+        layer = 0;
     } else if (layer > 1) {
-        return bad_parameter;
-    } else { // layer == 0 ro 1
-        return WriteCommand(0x41, mwcr1 | layer);
+        layer = 0;
     }
+    WriteCommand(0x41, mwcr1 | layer);
+    return prevlayer;
 }
 
 
@@ -1193,7 +1195,7 @@
             SelectDrawingLayer(1);
             clsw(FULLWINDOW);
         }
-        ret = SelectDrawingLayer(prevLayer);
+        SelectDrawingLayer(prevLayer);
     }
     ret = SetTextCursor(0,0);
     ret = locate(0,0);

--- a/RA8875.h	Thu Dec 29 20:06:00 2016 +0000
+++ b/RA8875.h	Sun Mar 19 21:41:24 2017 +0000
@@ -545,6 +545,9 @@
     /// be independently drawn on and shown. Additionally, complex
     /// operations involving both layers are permitted.
     ///
+    /// @attention If the current display configuration does not support
+    ///     multiple layers, then layer 0 will be selected.
+    ///
     /// @code
     ///     //lcd.SetLayerMode(OnlyLayer0); // default is layer 0
     ///     lcd.rect(400,130, 475,155,Brown);
@@ -561,9 +564,9 @@
     ///
     /// @param[in] layer is 0 or 1 to select the layer for subsequent 
     ///     commands.
-    /// @returns success/failure code. See @ref RetCode_t.
-    ///
-    RetCode_t SelectDrawingLayer(uint16_t layer);
+    /// @returns the previous drawing layer; 0 or 1.
+    ///
+    virtual uint16_t SelectDrawingLayer(uint16_t layer);
  
     
     /// Get the currently active drawing layer.
@@ -585,7 +588,7 @@
     ///
     /// @returns the current drawing layer; 0 or 1.
     /// 
-    uint16_t GetDrawingLayer(void);
+    virtual uint16_t GetDrawingLayer(void);
  
     
     /// Set the Layer presentation mode.