Bitmap mode

src/main/kc/include/bitmap-draw.h

@@ -2,12 +2,12 @@
 // Currently it can only plot on the first 256 x-positions.
 
 // Initialize the bitmap plotter tables for a specific bitmap
-void bitmap_init(char* bitmap);
+void bitmap_init(word bitmap_address);
 
 // Clear all graphics on the bitmap
 void bitmap_clear();
 
-void bitmap_plot(char x, char y);
+void bitmap_plot(word x, word y);
 
 // Draw a line on the bitmap
-void bitmap_line(char x0, char x1, char y0, char y1);
+void bitmap_line(word x0, word x1, word y0, word y1);

src/main/kc/include/cx16-vera.h

@@ -164,15 +164,14 @@ byte const VERA_LAYER_COLOR_DEPTH_8BPP = 0x03;
 byte const VERA_LAYER_COLOR_DEPTH_MASK = 0x03;
 byte const VERA_LAYER_COLOR_DEPTH[4] = {1, 2, 4, 8};
 
-
 // $9F2D	L0_CONFIG   Layer 0 Configuration
 char * const VERA_L0_CONFIG = 0x9f2d;
 // Bit 2: Bitmap Mode	(0:tile mode, 1: bitmap mode)
-char const VERA_L0_CONFIG_MODE_TILE = 0x00;
-char const VERA_L0_CONFIG_MODE_BITMAP = 0x04;
+char const VERA_LAYER_CONFIG_MODE_TILE = 0x00;
+char const VERA_LAYER_CONFIG_MODE_BITMAP = 0x04;
 // Bit 3: T256C	        (0: tiles use a 16-color foreground and background color, 1: tiles use a 256-color foreground color) (only relevant in 1bpp modes)
-char const VERA_L0_CONFIG_16C = 0x00;
-char const VERA_L0_CONFIG_256C = 0x08;
+char const VERA_LAYER_CONFIG_16C = 0x00;
+char const VERA_LAYER_CONFIG_256C = 0x08;
 // $9F2E	L0_MAPBASE	    Layer 0 Map Base Address (16:9)
 char * const VERA_L0_MAPBASE = 0x9f2e;
 // $9F2F	L0_TILEBASE	    Layer 0 Tile Base
@@ -197,12 +196,6 @@ char * const VERA_L0_VSCROLL_L = 0x9f32;
 char * const VERA_L0_VSCROLL_H = 0x9f33;
 // $9F34	L1_CONFIG   Layer 1 Configuration
 char * const VERA_L1_CONFIG = 0x9f34;
-// Bit 2: Bitmap Mode	(0:tile mode, 1: bitmap mode)
-char const VERA_L1_CONFIG_MODE_TILE = 0x00;
-char const VERA_L1_CONFIG_MODE_BITMAP = 0x04;
-// Bit 3: T256C	        (0: tiles use a 16-color foreground and background color, 1: tiles use a 256-color foreground color) (only relevant in 1bpp modes)
-char const VERA_L1_CONFIG_16C = 0x00;
-char const VERA_L1_CONFIG_256C = 0x08;
 // $9F35	L1_MAPBASE	    Layer 1 Map Base Address (16:9)
 char * const VERA_L1_MAPBASE = 0x9f35;
 // $9F36	L1_TILEBASE	    Layer 1 Tile Base

src/main/kc/lib/bitmap-c64.c

@@ -0,0 +1,111 @@
+// Simple single-color (320x200) bitmap routines
+#include <bitmap2.h>
+#include <string.h>
+
+// The adddress of the bitmap screen (used for colors)
+char* bitmap_screen;
+// The adddress of the bitmap graphics (used for pixels)
+char* bitmap_gfx;
+
+// Tables for the plotter - initialized by calling bitmap_init();
+const char bitmap_plot_ylo[256];
+const char bitmap_plot_yhi[256];
+const char bitmap_plot_bit[256];
+
+// Initialize bitmap plotting tables
+void bitmap_init(char* gfx, char* screen) {
+    bitmap_gfx = gfx;
+    bitmap_screen = screen;
+    char bits = $80;
+    for(char x : 0..255) {
+        bitmap_plot_bit[x] = bits;
+        bits >>= 1;
+        if(bits==0) {
+          bits = $80;
+        }
+    }
+    char* yoffs = gfx;
+    for(char y : 0..255) {
+        bitmap_plot_ylo[y] = y&$7 | <yoffs;
+        bitmap_plot_yhi[y] = >yoffs;
+        if((y&$7)==7) {
+            yoffs = yoffs + 40*8;
+        }
+    }
+}
+
+// Clear all graphics on the bitmap
+// bgcol - the background color to fill the screen with
+// fgcol - the foreground color to fill the screen with
+void bitmap_clear(char bgcol, char fgcol) {
+    char col = fgcol*0x10 + bgcol;
+    memset(bitmap_screen, col, 1000uw);
+    memset(bitmap_gfx, 0, 8000uw);
+}
+
+// Plot a single dot in the bitmap
+void bitmap_plot(unsigned int x, char y) {
+    char* plotter = (char*) { bitmap_plot_yhi[y], bitmap_plot_ylo[y] };
+    plotter += ( x & $fff8 );
+    *plotter |= bitmap_plot_bit[<x];
+}
+
+// Draw a line on the bitmap using bresenhams algorithm
+void bitmap_line(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2) {
+    unsigned int x = x1;
+    unsigned int y = y1;
+    unsigned int dx = abs_u16(x2-x1);
+    unsigned int dy = abs_u16(y2-y1);
+    if(dx==0 && dy==0) {
+        bitmap_plot(x,(char)y);
+        return;
+    }
+    unsigned int sx = sgn_u16(x2-x1);
+    unsigned int sy = sgn_u16(y2-y1);
+    if(dx > dy) {
+        // X is the driver
+        unsigned int e = dy/2;
+        do  {
+            bitmap_plot(x,(char)y);
+            x += sx;
+            e += dy;
+            if(dx < e) {
+                y += sy;
+                e -= dx;
+            }
+        } while (x != x2);
+    } else {
+        // Y is the driver
+        unsigned int e = dx/2;
+        do  {
+            bitmap_plot(x,(char)y);
+            y += sy;
+            e += dx;
+            if(dy<e) {
+                x += sx;
+                e -= dy;
+            }
+        } while (y != y2);
+    }
+    bitmap_plot(x,(char)y);
+}
+
+// Get the absolute value of a 16-bit unsigned number treated as a signed number.
+unsigned int abs_u16(unsigned int w) {
+    if(>w&0x80) {
+        return -w;
+    } else {
+        return w;
+    }
+}
+
+// Get the sign of a 16-bit unsigned number treated as a signed number.
+// Returns unsigned -1 if the number is
+unsigned int sgn_u16(unsigned int w) {
+    if(>w&0x80) {
+        return -1;
+    } else {
+        return 1;
+    }
+}
+

src/main/kc/lib/bitmap-cx16.c

@@ -0,0 +1,112 @@
+// Simple single-color (320x200) bitmap routines
+#include <bitmap2.h>
+#include <string.h>
+#include <veralib.h>
+#include <printf.h> // TODO
+
+// The adddress of the bitmap screen (used for colors)
+char* bitmap_screen;
+// The adddress of the bitmap graphics (used for pixels)
+char* bitmap_gfx;
+
+// Tables for the plotter - initialized by calling bitmap_init();
+const char bitmap_plot_ylo[256];
+const char bitmap_plot_yhi[256];
+const char bitmap_plot_bit[256];
+
+// Initialize bitmap plotting tables
+void bitmap_init(char* gfx, char* screen) {
+    bitmap_gfx = gfx;
+    bitmap_screen = screen;
+    char bits = $80;
+    for(char x : 0..255) {
+        bitmap_plot_bit[x] = bits;
+        bits >>= 1;
+        if(bits==0) {
+          bits = $80;
+        }
+    }
+    char* yoffs = gfx;
+    for(char y : 0..255) {
+        bitmap_plot_ylo[y] = y&$7 | <yoffs;
+        bitmap_plot_yhi[y] = >yoffs;
+        if((y&$7)==7) {
+            yoffs = yoffs + 40*8;
+        }
+    }
+}
+
+// Clear all graphics on the bitmap
+// bgcol - the background color to fill the screen with
+// fgcol - the foreground color to fill the screen with
+void bitmap_clear(char bgcol, char fgcol) {
+    memset_vram(0,bitmap_gfx,0, 320*4);
+    printf("done");
+}
+
+// Plot a single dot in the bitmap
+void bitmap_plot(unsigned int x, char y) {
+    char* plotter = (char*) { bitmap_plot_yhi[y], bitmap_plot_ylo[y] };
+    plotter += ( x & $fff8 );
+    *plotter |= bitmap_plot_bit[<x];
+}
+
+// Draw a line on the bitmap using bresenhams algorithm
+void bitmap_line(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2) {
+    unsigned int x = x1;
+    unsigned int y = y1;
+    unsigned int dx = abs_u16(x2-x1);
+    unsigned int dy = abs_u16(y2-y1);
+    if(dx==0 && dy==0) {
+        bitmap_plot(x,(char)y);
+        return;
+    }
+    unsigned int sx = sgn_u16(x2-x1);
+    unsigned int sy = sgn_u16(y2-y1);
+    if(dx > dy) {
+        // X is the driver
+        unsigned int e = dy/2;
+        do  {
+            bitmap_plot(x,(char)y);
+            x += sx;
+            e += dy;
+            if(dx < e) {
+                y += sy;
+                e -= dx;
+            }
+        } while (x != x2);
+    } else {
+        // Y is the driver
+        unsigned int e = dx/2;
+        do  {
+            bitmap_plot(x,(char)y);
+            y += sy;
+            e += dx;
+            if(dy<e) {
+                x += sx;
+                e -= dy;
+            }
+        } while (y != y2);
+    }
+    bitmap_plot(x,(char)y);
+}
+
+// Get the absolute value of a 16-bit unsigned number treated as a signed number.
+unsigned int abs_u16(unsigned int w) {
+    if(>w&0x80) {
+        return -w;
+    } else {
+        return w;
+    }
+}
+
+// Get the sign of a 16-bit unsigned number treated as a signed number.
+// Returns unsigned -1 if the number is
+unsigned int sgn_u16(unsigned int w) {
+    if(>w&0x80) {
+        return -1;
+    } else {
+        return 1;
+    }
+}
+

src/main/kc/lib/bitmap-draw-c64.c

@@ -0,0 +1,147 @@
+// Plot and line drawing routines for HIRES bitmaps
+// Currently it can only plot on the first 256 x-positions.
+
+#include <bitmap-draw.h>
+
+// Tables for the plotter - initialized by calling bitmap_draw_init();
+const char bitmap_plot_xlo[256];
+const char bitmap_plot_xhi[256];
+const char bitmap_plot_ylo[256];
+const char bitmap_plot_yhi[256];
+const char bitmap_plot_bit[256];
+
+// Initialize the bitmap plotter tables for a specific bitmap
+void bitmap_init(char* bitmap) {
+    char bits = $80;
+    for(char x : 0..255) {
+        bitmap_plot_xlo[x] = x&$f8;
+        bitmap_plot_xhi[x] = >bitmap;
+        bitmap_plot_bit[x] = bits;
+        bits = bits>>1;
+        if(bits==0) {
+          bits = $80;
+        }
+    }
+    char* yoffs = $0;
+    for(char y : 0..255) {
+        bitmap_plot_ylo[y] = y&$7 | <yoffs;
+        bitmap_plot_yhi[y] = >yoffs;
+        if((y&$7)==7) {
+            yoffs = yoffs + 40*8;
+        }
+    }
+}
+
+// Clear all graphics on the bitmap
+void bitmap_clear() {
+    char* bitmap = (char*) { bitmap_plot_xhi[0], bitmap_plot_xlo[0] };
+    for( char y: 0..39 ) {
+        for( char x: 0..199 ) {
+            *bitmap++ = 0;
+        }
+    }
+}
+
+void bitmap_plot(char x, char y) {
+    // Needs unsigned int arrays arranged as two underlying char arrays to allow char* plotter_x = plot_x[x]; - and eventually - char* plotter = plot_x[x] + plot_y[y];
+    unsigned int plotter_x = { bitmap_plot_xhi[x], bitmap_plot_xlo[x] };
+    unsigned int plotter_y = { bitmap_plot_yhi[y], bitmap_plot_ylo[y] };
+    char* plotter = plotter_x+plotter_y;
+    *plotter = *plotter | bitmap_plot_bit[x];
+}
+
+
+// Draw a line on the bitmap
+void bitmap_line(char x0, char x1, char y0, char y1) {
+    char xd;
+    char yd;
+    if(x0<x1) {
+        xd = x1-x0;
+        if(y0<y1) {
+            yd = y1-y0;
+            if(yd<xd) {
+                bitmap_line_xdyi(x0, y0, x1, xd, yd);
+            } else {
+                bitmap_line_ydxi(y0, x0, y1, yd, xd);
+            }
+        } else {
+            yd = y0-y1;
+            if(yd<xd) {
+                bitmap_line_xdyd(x0, y0, x1, xd, yd);
+            } else {
+                bitmap_line_ydxd(y1, x1, y0, yd, xd);
+            }
+        }
+    } else {
+        xd = x0-x1;
+        if(y0<y1) {
+            yd = y1-y0;
+            if(yd<xd) {
+                bitmap_line_xdyd(x1, y1, x0, xd, yd);
+            } else {
+                bitmap_line_ydxd(y0, x0, y1, yd, xd);
+            }
+        } else {
+            yd = y0-y1;
+            if(yd<xd) {
+                bitmap_line_xdyi(x1, y1, x0, xd, yd);
+            } else {
+                bitmap_line_ydxi(y1, x1, y0, yd, xd);
+            }
+        }
+    }
+}
+
+void bitmap_line_xdyi(char x, char y, char x1, char xd, char yd) {
+  char e = yd>>1;
+  do  {
+      bitmap_plot(x,y);
+      x++;
+      e = e+yd;
+      if(xd<e) {
+          y++;
+          e = e - xd;
+      }
+  } while (x!=(x1+1));
+}
+
+void bitmap_line_xdyd(char x, char y, char x1, char xd, char yd) {
+  char e = yd>>1;
+  do  {
+      bitmap_plot(x,y);
+      x++;
+      e = e+yd;
+      if(xd<e) {
+          y--;
+          e = e - xd;
+      }
+  } while (x!=(x1+1));
+}
+
+void bitmap_line_ydxi(char y, char x, char y1, char yd, char xd) {
+  char e = xd>>1;
+  do  {
+      bitmap_plot(x,y);
+      y++;
+      e = e+xd;
+      if(yd<e) {
+          x++;
+          e = e - yd;
+      }
+  } while (y!=(y1+1));
+}
+
+void bitmap_line_ydxd(char y, char x, char y1, char yd, char xd) {
+  char e = xd>>1;
+  do  {
+      bitmap_plot(x,y);
+      y = y++;
+      e = e+xd;
+      if(yd<e) {
+          x--;
+          e = e - yd;
+      }
+  } while (y!=(y1+1));
+}
+
+

src/main/kc/lib/bitmap-draw-cx16.c

@@ -0,0 +1,143 @@
+// Plot and line drawing routines for HIRES bitmaps
+// Currently it can only plot on the first 256 x-positions.
+
+#include <bitmap-draw.h>
+#include <veralib.h>
+
+// Tables for the plotter - initialized by calling bitmap_draw_init();
+const word bitmap_plot_y[640];
+const byte bitmap_plot_bit[8];
+
+word bitmap = 0;
+// Initialize the bitmap plotter tables for a specific bitmap
+void bitmap_init(word bitmap_address) {
+    bitmap = bitmap_address;
+    word yoffs = $0;
+    byte bit = $80;
+    for(word x : 0..7) {
+        bitmap_plot_bit[x] = bit;
+        bit >>= 1;
+    }
+    for(word y : 0..600) {
+        bitmap_plot_y[y] = yoffs;
+        yoffs = yoffs + 80;
+    }
+}
+
+// Clear all graphics on the bitmap
+void bitmap_clear() {
+    word bitmap_address = bitmap;
+    for( word y: 0..600 ) {
+        for( word x: 0..40 ) {
+            vera_vram_bank_offset(0,(word)bitmap_address,VERA_INC_0);
+            *VERA_DATA0 = 0;
+            bitmap_address++;
+        }
+    }
+}
+
+void bitmap_plot(word x, word y) {
+    // Needs unsigned int arrays arranged as two underlying char arrays to allow char* plotter_x = plot_x[x]; - and eventually - char* plotter = plot_x[x] + plot_y[y];
+    word plotter_x = x>>3;
+    word plotter_y = bitmap_plot_y[y];
+
+    word plotter = bitmap+plotter_x+plotter_y;
+    vera_vram_bank_offset(0,(word)plotter,VERA_INC_0);
+    *VERA_DATA0 = *VERA_DATA0 | bitmap_plot_bit[x&$07];
+}
+
+
+// Draw a line on the bitmap
+void bitmap_line(word x0, word x1, word y0, word y1) {
+    word xd;
+    word yd;
+    if(x0<x1) {
+        xd = x1-x0;
+        if(y0<y1) {
+            yd = y1-y0;
+            if(yd<xd) {
+                bitmap_line_xdyi(x0, y0, x1, xd, yd);
+            } else {
+                bitmap_line_ydxi(y0, x0, y1, yd, xd);
+            }
+        } else {
+            yd = y0-y1;
+            if(yd<xd) {
+                bitmap_line_xdyd(x0, y0, x1, xd, yd);
+            } else {
+                bitmap_line_ydxd(y1, x1, y0, yd, xd);
+            }
+        }
+    } else {
+        xd = x0-x1;
+        if(y0<y1) {
+            yd = y1-y0;
+            if(yd<xd) {
+                bitmap_line_xdyd(x1, y1, x0, xd, yd);
+            } else {
+                bitmap_line_ydxd(y0, x0, y1, yd, xd);
+            }
+        } else {
+            yd = y0-y1;
+            if(yd<xd) {
+                bitmap_line_xdyi(x1, y1, x0, xd, yd);
+            } else {
+                bitmap_line_ydxi(y1, x1, y0, yd, xd);
+            }
+        }
+    }
+}
+
+void bitmap_line_xdyi(word x, word y, word x1, word xd, word yd) {
+  word e = yd>>1;
+  do  {
+      bitmap_plot(x,y);
+      x++;
+      e = e+yd;
+      if(xd<e) {
+          y++;
+          e = e - xd;
+      }
+  } while (x!=(x1+1));
+}
+
+void bitmap_line_xdyd(word x, word y, word x1, word xd, word yd) {
+  word e = yd>>1;
+  do  {
+      bitmap_plot(x,y);
+      x++;
+      e = e+yd;
+      if(xd<e) {
+          y--;
+          e = e - xd;
+      }
+  } while (x!=(x1+1));
+}
+
+void bitmap_line_ydxi(word y, word x, word y1, word yd, word xd) {
+  word e = xd>>1;
+  do  {
+      bitmap_plot(x,y);
+      y++;
+      e = e+xd;
+      if(yd<e) {
+          x++;
+          e = e - yd;
+      }
+  } while (y!=(y1+1));
+}
+
+void bitmap_line_ydxd(word y, word x, word y1, word yd, word xd) {
+  word e = xd>>1;
+  do  {
+      bitmap_plot(x,y);
+      y = y++;
+      e = e+xd;
+      if(yd<e) {
+          x--;
+          e = e - yd;
+      }
+  } while (y!=(y1+1));
+}
+
+

src/main/kc/lib/bitmap-draw.c

@@ -1,147 +1,11 @@
-// Plot and line drawing routines for HIRES bitmaps
-// Currently it can only plot on the first 256 x-positions.
-
+// Provides provide bitmap output
+// Currently C64/PLUS4/VIC20/CX16 platforms are supported
 #include <bitmap-draw.h>
 
-// Tables for the plotter - initialized by calling bitmap_draw_init();
-const char bitmap_plot_xlo[256];
-const char bitmap_plot_xhi[256];
-const char bitmap_plot_ylo[256];
-const char bitmap_plot_yhi[256];
-const char bitmap_plot_bit[256];
-
-// Initialize the bitmap plotter tables for a specific bitmap
-void bitmap_init(char* bitmap) {
-    char bits = $80;
-    for(char x : 0..255) {
-        bitmap_plot_xlo[x] = x&$f8;
-        bitmap_plot_xhi[x] = >bitmap;
-        bitmap_plot_bit[x] = bits;
-        bits = bits>>1;
-        if(bits==0) {
-          bits = $80;
-        }
-    }
-    char* yoffs = $0;
-    for(char y : 0..255) {
-        bitmap_plot_ylo[y] = y&$7 | <yoffs;
-        bitmap_plot_yhi[y] = >yoffs;
-        if((y&$7)==7) {
-            yoffs = yoffs + 40*8;
-        }
-    }
-}
-
-// Clear all graphics on the bitmap
-void bitmap_clear() {
-    char* bitmap = (char*) { bitmap_plot_xhi[0], bitmap_plot_xlo[0] };
-    for( char y: 0..39 ) {
-        for( char x: 0..199 ) {
-            *bitmap++ = 0;
-        }
-    }
-}
-
-void bitmap_plot(char x, char y) {
-    // Needs unsigned int arrays arranged as two underlying char arrays to allow char* plotter_x = plot_x[x]; - and eventually - char* plotter = plot_x[x] + plot_y[y];
-    unsigned int plotter_x = { bitmap_plot_xhi[x], bitmap_plot_xlo[x] };
-    unsigned int plotter_y = { bitmap_plot_yhi[y], bitmap_plot_ylo[y] };
-    char* plotter = plotter_x+plotter_y;
-    *plotter = *plotter | bitmap_plot_bit[x];
-}
-
-
-// Draw a line on the bitmap
-void bitmap_line(char x0, char x1, char y0, char y1) {
-    char xd;
-    char yd;
-    if(x0<x1) {
-        xd = x1-x0;
-        if(y0<y1) {
-            yd = y1-y0;
-            if(yd<xd) {
-                bitmap_line_xdyi(x0, y0, x1, xd, yd);
-            } else {
-                bitmap_line_ydxi(y0, x0, y1, yd, xd);
-            }
-        } else {
-            yd = y0-y1;
-            if(yd<xd) {
-                bitmap_line_xdyd(x0, y0, x1, xd, yd);
-            } else {
-                bitmap_line_ydxd(y1, x1, y0, yd, xd);
-            }
-        }
-    } else {
-        xd = x0-x1;
-        if(y0<y1) {
-            yd = y1-y0;
-            if(yd<xd) {
-                bitmap_line_xdyd(x1, y1, x0, xd, yd);
-            } else {
-                bitmap_line_ydxd(y0, x0, y1, yd, xd);
-            }
-        } else {
-            yd = y0-y1;
-            if(yd<xd) {
-                bitmap_line_xdyi(x1, y1, x0, xd, yd);
-            } else {
-                bitmap_line_ydxi(y1, x1, y0, yd, xd);
-            }
-        }
-    }
-}
-
-void bitmap_line_xdyi(char x, char y, char x1, char xd, char yd) {
-  char e = yd>>1;
-  do  {
-      bitmap_plot(x,y);
-      x++;
-      e = e+yd;
-      if(xd<e) {
-          y++;
-          e = e - xd;
-      }
-  } while (x!=(x1+1));
-}
-
-void bitmap_line_xdyd(char x, char y, char x1, char xd, char yd) {
-  char e = yd>>1;
-  do  {
-      bitmap_plot(x,y);
-      x++;
-      e = e+yd;
-      if(xd<e) {
-          y--;
-          e = e - xd;
-      }
-  } while (x!=(x1+1));
-}
-
-void bitmap_line_ydxi(char y, char x, char y1, char yd, char xd) {
-  char e = xd>>1;
-  do  {
-      bitmap_plot(x,y);
-      y++;
-      e = e+xd;
-      if(yd<e) {
-          x++;
-          e = e - yd;
-      }
-  } while (y!=(y1+1));
-}
-
-void bitmap_line_ydxd(char y, char x, char y1, char yd, char xd) {
-  char e = xd>>1;
-  do  {
-      bitmap_plot(x,y);
-      y = y++;
-      e = e+xd;
-      if(yd<e) {
-          x--;
-          e = e - yd;
-      }
-  } while (y!=(y1+1));
-}
-
-
+#if defined(__CX16__)
+#include "bitmap-draw-cx16.c"
+#elif defined(__C64__)
+#include "bitmap-draw-c64.c"
+#else
+#error "Target platform does not support bitmap-draw.h"
+#endif

src/main/kc/lib/bitmap2.c

@@ -1,111 +1,11 @@
-// Simple single-color (320x200) bitmap routines
+// Provides provide bitmap output
+// Currently C64/PLUS4/VIC20/CX16 platforms are supported
 #include <bitmap2.h>
-#include <string.h>
-
-// The adddress of the bitmap screen (used for colors)
-char* bitmap_screen;
-// The adddress of the bitmap graphics (used for pixels)
-char* bitmap_gfx;
-
-// Tables for the plotter - initialized by calling bitmap_init();
-const char bitmap_plot_ylo[256];
-const char bitmap_plot_yhi[256];
-const char bitmap_plot_bit[256];
-
-// Initialize bitmap plotting tables
-void bitmap_init(char* gfx, char* screen) {
-    bitmap_gfx = gfx;
-    bitmap_screen = screen;
-    char bits = $80;
-    for(char x : 0..255) {
-        bitmap_plot_bit[x] = bits;
-        bits >>= 1;
-        if(bits==0) {
-          bits = $80;
-        }
-    }
-    char* yoffs = gfx;
-    for(char y : 0..255) {
-        bitmap_plot_ylo[y] = y&$7 | <yoffs;
-        bitmap_plot_yhi[y] = >yoffs;
-        if((y&$7)==7) {
-            yoffs = yoffs + 40*8;
-        }
-    }
-}
-
-// Clear all graphics on the bitmap
-// bgcol - the background color to fill the screen with
-// fgcol - the foreground color to fill the screen with
-void bitmap_clear(char bgcol, char fgcol) {
-    char col = fgcol*0x10 + bgcol;
-    memset(bitmap_screen, col, 1000uw);
-    memset(bitmap_gfx, 0, 8000uw);
-}
-
-// Plot a single dot in the bitmap
-void bitmap_plot(unsigned int x, char y) {
-    char* plotter = (char*) { bitmap_plot_yhi[y], bitmap_plot_ylo[y] };
-    plotter += ( x & $fff8 );
-    *plotter |= bitmap_plot_bit[<x];
-}
-
-// Draw a line on the bitmap using bresenhams algorithm
-void bitmap_line(unsigned int x1, unsigned int y1, unsigned int x2, unsigned int y2) {
-    unsigned int x = x1;
-    unsigned int y = y1;
-    unsigned int dx = abs_u16(x2-x1);
-    unsigned int dy = abs_u16(y2-y1);
-    if(dx==0 && dy==0) {
-        bitmap_plot(x,(char)y);
-        return;
-    }
-    unsigned int sx = sgn_u16(x2-x1);
-    unsigned int sy = sgn_u16(y2-y1);
-    if(dx > dy) {
-        // X is the driver
-        unsigned int e = dy/2;
-        do  {
-            bitmap_plot(x,(char)y);
-            x += sx;
-            e += dy;
-            if(dx < e) {
-                y += sy;
-                e -= dx;
-            }
-        } while (x != x2);
-    } else {
-        // Y is the driver
-        unsigned int e = dx/2;
-        do  {
-            bitmap_plot(x,(char)y);
-            y += sy;
-            e += dx;
-            if(dy<e) {
-                x += sx;
-                e -= dy;
-            }
-        } while (y != y2);
-    }
-    bitmap_plot(x,(char)y);
-}
-
-// Get the absolute value of a 16-bit unsigned number treated as a signed number.
-unsigned int abs_u16(unsigned int w) {
-    if(>w&0x80) {
-        return -w;
-    } else {
-        return w;
-    }
-}
-
-// Get the sign of a 16-bit unsigned number treated as a signed number.
-// Returns unsigned -1 if the number is
-unsigned int sgn_u16(unsigned int w) {
-    if(>w&0x80) {
-        return -1;
-    } else {
-        return 1;
-    }
-}
 
+#if defined(__CX16__)
+#include "bitmap-cx16.c"
+#elif defined(__C64__)
+#include "bitmap-c64.c"
+#else
+#error "Target platform does not support bitmap.h"
+#endif

src/main/kc/lib/conio-cx16.c

@@ -71,7 +71,7 @@ void conio_x16_init() {
     // Position cursor at current line
     char * const BASIC_CURSOR_LINE = 0xD6;
     char line = *BASIC_CURSOR_LINE;
-    vera_layer_mode_tile(1,(dword)0x00000,(dword)0x0F800,128,64,8,8,1);
+    vera_layer_mode_text(1,(dword)0x00000,(dword)0x0F800,128,64,8,8,16);
     screensize(&conio_screen_width, &conio_screen_height);
     screenlayer(1);
     vera_layer_set_textcolor(1, WHITE);

src/main/kc/lib/cx16.c

@@ -55,6 +55,24 @@ void memcpy_to_vram(char vbank, void* vdest, void* src, unsigned int num ) {
         *VERA_DATA0 = *s;
 }
 
+// Set block of memory to a value in VRAM.
+// Sets num bytes to a value to the memory block pointed to by destination in VRAM.
+// - vbank: Which 64K VRAM bank to put data into (0/1)
+// - vdest: The destination address in VRAM
+// - data: The value to set the vram with.
+// - num: The number of bytes to copy
+void memset_vram(char vbank, void* vdest, byte data, word num ) {
+    // Select DATA0
+    *VERA_CTRL &= ~VERA_ADDRSEL;
+    // Set address
+    *VERA_ADDRX_L = <vdest;
+    *VERA_ADDRX_M = >vdest;
+    *VERA_ADDRX_H = VERA_INC_1 | vbank;
+    // Transfer the data
+    for(word i = 0; i<num; i++)
+        *VERA_DATA0 = data;
+}
+
 // Copy block of memory (from VRAM to VRAM)
 // Copies the values from the location pointed by src to the location pointed by dest.
 // The method uses the VERA access ports 0 and 1 to copy data from and to in VRAM.

src/main/kc/lib/veralib.c

@@ -13,6 +13,15 @@
 
 // --- VERA addressing ---
 
+void vera_vram_bank_offset(byte bank, word offset, byte incr) {
+    // Select DATA0
+    *VERA_CTRL &= ~VERA_ADDRSEL;
+    // Set address
+    *VERA_ADDRX_L = <(offset);
+    *VERA_ADDRX_M = >(offset);
+    *VERA_ADDRX_H = bank | incr;
+}
+
 void vera_vram_address0(dword bankaddr, byte incr) {
     word* word_l = &(<bankaddr);
     word* word_h = &(>bankaddr);
@@ -35,13 +44,28 @@ void vera_vram_address1(dword bankaddr, byte incr) {
     *VERA_ADDRX_H = <(*word_h) | incr;
 }
 
+// --- VERA active display management ---
+
+void vera_display_set_scale_none() {
+    *VERA_DC_HSCALE = 128;
+    *VERA_DC_VSCALE = 128;
+}
+
+void vera_display_set_scale_double() {
+    *VERA_DC_HSCALE = 64;
+    *VERA_DC_VSCALE = 64;
+}
+
+void vera_display_set_scale_triple() {
+    *VERA_DC_HSCALE = 32;
+    *VERA_DC_VSCALE = 32;
+}
 // --- VERA layer management ---
 
 // Set the configuration of the layer.
 // - layer: Value of 0 or 1.
 // - config: Specifies the modes which are specified using T256C / 'Bitmap Mode' / 'Color Depth'.
 void vera_layer_set_config(byte layer, byte config) {
-    layer &= $1;
     byte* addr = vera_layer_config[layer];
     *addr = config;
 }
@@ -54,6 +78,31 @@ byte vera_layer_get_config(byte layer) {
     return *config;
 }
 
+// Set the configuration of the layer.
+// - layer: Value of 0 or 1.
+// - color_mode: Specifies the color mode to be VERA_LAYER_CONFIG_16 or VERA_LAYER_CONFIG_256 for text mode.
+void vera_layer_set_text_color_mode( byte layer, byte color_mode ) {
+    byte* addr = vera_layer_config[layer];
+    *addr &= ~VERA_LAYER_CONFIG_256C;
+    *addr |= color_mode;
+}
+
+// Set the configuration of the layer to bitmap mode.
+// - layer: Value of 0 or 1.
+void vera_layer_set_bitmap_mode( byte layer ) {
+    byte* addr = vera_layer_config[layer];
+    *addr &= ~VERA_LAYER_CONFIG_MODE_BITMAP;
+    *addr |= VERA_LAYER_CONFIG_MODE_BITMAP;
+}
+
+// Set the configuration of the layer to tilemap mode.
+// - layer: Value of 0 or 1.
+void vera_layer_set_tilemap_mode( byte layer ) {
+    byte* addr = vera_layer_config[layer];
+    *addr &= ~VERA_LAYER_CONFIG_MODE_BITMAP;
+    *addr |= VERA_LAYER_CONFIG_MODE_TILE;
+}
+
 // Set the map width or height of the layer.
 // - layer: Value of 0 or 1.
 inline void vera_layer_set_width_32(byte layer) {
@@ -293,8 +342,8 @@ dword vera_layer_get_tilebase_address(byte layer) {
 
 // Set the front color for text output. The old front text color setting is returned.
 // - layer: Value of 0 or 1.
-// - color: a 4 bit value ( decimal between 0 and 15).
-//   This will only work when the VERA is in 16 color mode!
+// - color: a 4 bit value ( decimal between 0 and 15) when the VERA works in 16x16 color text mode.
+//   An 8 bit value (decimal between 0 and 255) when the VERA works in 256 text mode.
 //   Note that on the VERA, the transparent color has value 0.
 byte vera_layer_set_textcolor(byte layer, byte color) {
     byte old = vera_layer_textcolor[layer];
@@ -308,7 +357,6 @@ byte vera_layer_set_textcolor(byte layer, byte color) {
 //   This will only work when the VERA is in 16 color mode!
 //   Note that on the VERA, the transparent color has value 0.
 byte vera_layer_get_textcolor(byte layer) {
-    layer &= $1;
     return vera_layer_textcolor[layer];
 }
 
@@ -318,7 +366,6 @@ byte vera_layer_get_textcolor(byte layer) {
 //   This will only work when the VERA is in 16 color mode!
 //   Note that on the VERA, the transparent color has value 0.
 byte vera_layer_set_backcolor(byte layer, byte color) {
-    layer &= $1;
     byte old = vera_layer_backcolor[layer];
     vera_layer_backcolor[layer] = color;
     return old;
@@ -330,7 +377,6 @@ byte vera_layer_set_backcolor(byte layer, byte color) {
 //   This will only work when the VERA is in 16 color mode!
 //   Note that on the VERA, the transparent color has value 0.
 byte vera_layer_get_backcolor(byte layer) {
-    layer &= $1;
     return vera_layer_backcolor[layer];
 }
 
@@ -340,8 +386,11 @@ byte vera_layer_get_backcolor(byte layer) {
 //   This will only work when the VERA is in 16 color mode!
 //   Note that on the VERA, the transparent color has value 0.
 byte vera_layer_get_color(byte layer) {
-    layer &= $1;
-    return ((vera_layer_backcolor[layer] << 4) | vera_layer_textcolor[layer]);
+    byte* addr = vera_layer_config[layer];
+    if( *addr & VERA_LAYER_CONFIG_256C )
+        return (vera_layer_textcolor[layer]);
+    else
+        return ((vera_layer_backcolor[layer] << 4) | vera_layer_textcolor[layer]);
 }
 
 
@@ -376,6 +425,7 @@ word vera_layer_get_rowskip(byte layer) {
 }
 
 
+
 // Set a vera layer in tile mode and configure the:
 // - layer: Value of 0 or 1.
 // - mapbase_address: A dword typed address (4 bytes), that specifies the full address of the map base.
@@ -485,6 +535,96 @@ void vera_layer_mode_tile(byte layer, dword mapbase_address, dword tilebase_addr
     vera_layer_set_tilebase(layer,tilebase);
 }
 
+
+// Set a vera layer in text mode and configure the:
+// - layer: Value of 0 or 1.
+// - mapbase_address: A dword typed address (4 bytes), that specifies the full address of the map base.
+//   The function does the translation from the dword that contains the 17 bit address,
+//   to the respective mapbase vera register.
+//   Note that the register only specifies bits 16:9 of the address,
+//   so the resulting address in the VERA VRAM is always aligned to a multiple of 512 bytes.
+// - tilebase_address: A dword typed address (4 bytes), that specifies the base address of the tile map.
+//   The function does the translation from the dword that contains the 17 bit address,
+//   to the respective tilebase vera register.
+//   Note that the resulting vera register holds only specifies bits 16:11 of the address,
+//   so the resulting address in the VERA VRAM is always aligned to a multiple of 2048 bytes!
+// - mapwidth: The width of the map in number of tiles.
+// - mapheight: The height of the map in number of tiles.
+// - tilewidth: The width of a tile, which can be 8 or 16 pixels.
+// - tileheight: The height of a tile, which can be 8 or 16 pixels.
+// - color_mode: The color mode, which can be 16 or 256.
+void vera_layer_mode_text(byte layer, dword mapbase_address, dword tilebase_address, word mapwidth, word mapheight, byte tilewidth, byte tileheight, word color_mode ) {
+    vera_layer_mode_tile( layer, mapbase_address, tilebase_address, mapwidth, mapheight, tilewidth, tileheight, 1 );
+    switch(color_mode) {
+        case 16:
+            vera_layer_set_text_color_mode( layer, VERA_LAYER_CONFIG_16C );
+            break;
+        case 256:
+            vera_layer_set_text_color_mode( layer, VERA_LAYER_CONFIG_256C );
+            break;
+    }
+}
+
+// Set a vera layer in bitmap mode and configure the:
+// - layer: Value of 0 or 1.
+// - mapbase_address: A dword typed address (4 bytes), that specifies the full address of the map base.
+//   The function does the translation from the dword that contains the 17 bit address,
+//   to the respective mapbase vera register.
+//   Note that the register only specifies bits 16:9 of the address,
+//   so the resulting address in the VERA VRAM is always aligned to a multiple of 512 bytes.
+// - tilebase_address: A dword typed address (4 bytes), that specifies the base address of the tile map.
+//   The function does the translation from the dword that contains the 17 bit address,
+//   to the respective tilebase vera register.
+//   Note that the resulting vera register holds only specifies bits 16:11 of the address,
+//   so the resulting address in the VERA VRAM is always aligned to a multiple of 2048 bytes!
+// - mapwidth: The width of the map in number of tiles.
+// - mapheight: The height of the map in number of tiles.
+// - tilewidth: The width of a tile, which can be 8 or 16 pixels.
+// - tileheight: The height of a tile, which can be 8 or 16 pixels.
+// - color_mode: The color mode, which can be 16 or 256.
+void vera_layer_mode_bitmap(byte layer, dword bitmap_address, word mapwidth, word color_depth ) {
+
+
+    // config
+    byte config = 0x00;
+    switch(color_depth) {
+        case 1:
+            config |= VERA_LAYER_COLOR_DEPTH_1BPP;
+            break;
+        case 2:
+            config |= VERA_LAYER_COLOR_DEPTH_2BPP;
+            break;
+        case 4:
+            config |= VERA_LAYER_COLOR_DEPTH_4BPP;
+            break;
+        case 8:
+            config |= VERA_LAYER_COLOR_DEPTH_8BPP;
+            break;
+    }
+    config = config | VERA_LAYER_CONFIG_MODE_BITMAP;
+    vera_layer_set_config(layer, config);
+
+    // tilebase
+    vera_tilebase_offset[layer] = <bitmap_address;
+    vera_tilebase_bank[layer] = (byte)>bitmap_address;
+    vera_tilebase_address[layer] = bitmap_address;
+
+    bitmap_address = bitmap_address >> 1;
+    byte tilebase = >(<bitmap_address);
+    tilebase &= VERA_LAYER_TILEBASE_MASK;
+
+    // mapwidth
+    switch(mapwidth) {
+        case 320:
+            tilebase |= VERA_TILEBASE_WIDTH_8;
+            break;
+        case 640:
+            tilebase |= VERA_TILEBASE_WIDTH_16;
+            break;
+    }
+    vera_layer_set_tilebase(layer,tilebase);
+}
+
 // --- TILE FUNCTIONS ---
 
 void vera_tile_area(byte layer, word tileindex, byte x, byte y, byte w, byte h, byte hflip, byte vflip, byte offset) {

src/test/kc/examples/cx16/bitmap_8bpp_320_x_200.c

@@ -0,0 +1,58 @@
+// Example program for the Commander X16.
+// Demonstrates the usage of the VERA tile map modes and layering.
+
+// Author: Sven Van de Velde
+
+// The default layer of the CX16 is layer 1, but the tiles are written on layer 0.
+
+// An explanation is given how this mode is organized, and how the tiles display and coloring works.
+// Pälette offsets are explained also.
+
+#include <conio.h>
+#include <printf.h>
+#include <bitmap-draw.h>
+
+char lines_x[] = { 60, 80, 110, 80, 60, 40, 10, 40, 60 };
+char lines_y[] = { 10, 40, 60, 80, 110, 80, 60, 40, 10 };
+char lines_cnt = 8;
+
+void lines() {
+    for(char l=0; l<lines_cnt;l++) {
+        bitmap_line(lines_x[l], lines_x[l+1], lines_y[l], lines_y[l+1]);
+    }
+}
+void main() {
+
+    vera_layer_mode_bitmap(0, (dword)0x04000, 640, 1);
+    vera_display_set_scale_none();
+
+    screenlayer(1);
+    textcolor(RED);
+    bgcolor(BLACK);
+    clrscr();
+
+    gotoxy(0,50);
+    printf("vera in bitmap mode, color depth 8 bits per pixel.\n");
+
+    printf("in this mode, it is possible to display graphics in 256 colors.\n\n");
+
+    vera_layer_show(0);
+
+    bitmap_init(0x4000);
+    bitmap_clear();
+
+    bitmap_plot( 2, 2);
+    bitmap_plot( 10, 2);
+    bitmap_plot( 10, 10);
+
+    lines();
+
+
+    while(!kbhit());
+
+    screenlayer(1);
+    textcolor(WHITE);
+    bgcolor(BLUE);
+    clrscr();
+
+}

src/test/kc/examples/cx16/tilemap_1bpp_8_x_8_16_color.c

@@ -0,0 +1,47 @@
+// Example program for the Commander X16.
+// Demonstrates the usage of the VERA tile map modes and layering.
+
+// Author: Sven Van de Velde
+
+// The default layer of the CX16 is layer 1, but the tiles are written on layer 0.
+// The CX16 starts in tile map mode, 1BPP in 16 color mode, and uses 8x8 tiles.
+
+// An explanation is given how this mode is organized, and how the tiles display and coloring works.
+// Pälette offsets are explained also.
+
+#include <veralib.h>
+#include <printf.h>
+
+void main() {
+
+    textcolor(WHITE);
+    bgcolor(BLACK);
+    clrscr();
+
+    // Configure the VERA card to work in text, 16x16 mode.
+    // The color mode is here 16 colors, indicating 16x16 color mode, (16 foreground and 16 background colors).
+    vera_layer_set_text_color_mode( 1, VERA_LAYER_CONFIG_16C );
+
+    // or you can use the below statement, but that includes setting a "mode", including
+    // layer, map base address, tile base address, map width, map height, tile width, tile height, color mode.
+    //vera_layer_mode_text(1, 0x00000, 0x0F800, 128, 128, 8, 8, 16);
+
+    for(byte c:0..255) {
+        bgcolor(c);
+        printf(" ****** ");
+    }
+
+    vera_layer_show(1);
+
+    gotoxy(0,50);
+    textcolor(WHITE);
+    bgcolor(BLACK);
+    printf("vera in text mode 8 x 8, color depth 1 bits per pixel.\n");
+    printf("in this mode, tiles are 8 pixels wide and 8 pixels tall.\n");
+    printf("each character can have a variation of 16 foreground colors and 16 background colors.\n");
+    printf("here we display 6 stars (******) each with a different color.\n");
+    printf("however, the first color will always be transparent (black).\n");
+    printf("in this mode, the background color cannot be set and is always transparent.\n");
+
+    while(!kbhit());
+}

src/test/kc/examples/cx16/tilemap_1bpp_8_x_8_256_color.c

@@ -0,0 +1,47 @@
+// Example program for the Commander X16.
+// Demonstrates the usage of the VERA tile map modes and layering.
+
+// Author: Sven Van de Velde
+
+// The default layer of the CX16 is layer 1, but the tiles are written on layer 0.
+// The CX16 starts in tile map mode, 1BPP in 16 color mode, and uses 8x8 tiles.
+
+// An explanation is given how this mode is organized, and how the tiles display and coloring works.
+// Pälette offsets are explained also.
+
+#include <veralib.h>
+#include <printf.h>
+
+void main() {
+
+    textcolor(WHITE);
+    bgcolor(BLACK);
+    clrscr();
+
+    // Configure the VERA card to work in text, 256 mode.
+   // The color mode is here 256 colors, (256 foreground on a black transparent background).
+     vera_layer_mode_text( 1, 0x00000, 0x0F800, 128, 128, 8, 8, 256 );
+
+    // or you can use the below statement, but that includes setting a "mode", including
+    // layer, map base address, tile base address, map width, map height, tile width, tile height, color mode.
+    //vera_layer_mode_text(1, 0x00000, 0x0F800, 128, 128, 8, 8, 256);
+
+    for(byte c:0..255) {
+        textcolor(c);
+        printf(" ****** ");
+    }
+
+    vera_layer_show(1);
+
+    gotoxy(0,50);
+    textcolor(WHITE);
+    bgcolor(BLACK);
+    printf("vera in text mode 8 x 8, color depth 1 bits per pixel.\n");
+    printf("in this mode, tiles are 8 pixels wide and 8 pixels tall.\n");
+    printf("each character can have a variation of 256 foreground colors.\n");
+    printf("here we display 6 stars (******) each with a different color.\n");
+    printf("however, the first color will always be transparent (black).\n");
+    printf("in this mode, the background color cannot be set and is always transparent.\n");
+
+    while(!kbhit());
+}