Merge pull request #45 from pimoroni/blend_modes

added new blend modes include multiply, add, subtract, dissolve, etc.…

examples/CMakeLists.txt

@@ -5,4 +5,5 @@ add_subdirectory(audio)
 add_subdirectory(sprites)
 add_subdirectory(colour)
 #add_subdirectory(sfx)
-add_subdirectory(music)
+add_subdirectory(music)
+add_subdirectory(blend_modes)

examples/blend_modes/CMakeLists.txt

@@ -0,0 +1,7 @@
+picosystem_executable(
+    blend_modes
+    blend_modes.cpp
+)
+
+pixel_double(blend_modes)
+disable_startup_logo(blend_modes)

examples/sprites/sprites.cpp

@@ -56,11 +56,12 @@ float deg_to_rad(float d) {
 // draw the world
 void draw(uint32_t tick) {
   // clear the background
-  pen(2, 3, 4);
+  alpha();
+  pen(1, 1, 1);
   clear();
 
   pen(10, 10, 10);
-  text("Choose your weapon:", 10, 10);
+  text("Choose your weapon:", 8, 10);
 
   // animate towards the selected weapons angle
   static float angle = 0.0f;
@@ -97,34 +98,45 @@ void draw(uint32_t tick) {
     // size to draw weapon (closer = larger)
     int32_t scale = ((cos(deg_to_rad(item_angle)) + 1.0f) * 8.0f) + 8.0f;
 
-    int32_t a = scale / 1.5;
-    a = a > 15 ? 15 : a;
-
     // draw the shadow
-    alpha(a / 8);
-    pen(1, 1, 1);
-    int32_t sw = scale + (bounce / 3);
-    int32_t sh = sw / 3;
-    fellipse(60 + x, 55 + y + (scale / 1.2), sw / 2, sh / 2);
+    blend(PEN);
+    int32_t sw = scale + (bounce / 2);
+    int32_t sh = sw / 4;
+    pen(0, 0, 0);
+    sprite(
+      weapons[i].id,                                        // sprite id
+      60 + x - (sw / 2), 50 + y + (scale / 1.2),  // position
+      1, 1,
+      sw, sh                                        // size
+    );
+
+    blend(ALPHA);
 
     // draw the weapon sprite
+    int32_t a = ((cos(deg_to_rad(item_angle)) + 1.0f) * 6.0f) + 4.0f;
+    a = a > 15 ? 15 : a;
     alpha(a);
     sprite(
       weapons[i].id,                                        // sprite id
       60 + x - (scale / 2), 55 + y - (scale / 2) + bounce,  // position
       1, 1,
       scale, scale                                          // size
     );
+    alpha(15);
+
+    //pen(15, 15, 15);
+    //text(str(a), 60 + x - (scale / 2), 55 + y - (scale / 2) + bounce);
   }
 
-  alpha(15);
+
 
   // centre name of weapon at bottom of screen
-  int label_width = 40;//text_width(weapons[selected].name);
-  pen(8, 11, 11);
-  frect(60 - label_width / 2 - 3, 104 - 3, label_width + 6, 13);
+  int32_t lw, lh;
+  measure(weapons[selected].name, lw, lh);
+  pen(12, 12, 12);
+  frect(60 - lw / 2 - 3, 104 - 3, lw + 6, 13);
   pen(0, 0, 0);
-  text(weapons[selected].name, 60 - (label_width / 2), 104);
+  text(weapons[selected].name, 60 - (lw / 2), 104);
 }
 
 

libraries/assets.cpp

@@ -69,8 +69,8 @@ namespace picosystem {
       {5, 0xf8, 0x18, 0x30, 0x30, 0x60, 0x60, 0x60, 0x00},
       {5, 0x70, 0xd8, 0xd8, 0x70, 0xd8, 0xd8, 0x70, 0x00},
       {5, 0x70, 0xd8, 0xd8, 0x78, 0x18, 0x98, 0x70, 0x00},
-      {2, 0x00, 0xc0, 0xc0, 0x00, 0xc0, 0xc0, 0x00, 0x00},
-      {2, 0x00, 0xc0, 0xc0, 0x00, 0xc0, 0xc0, 0xc0, 0x00},
+      {2, 0x00, 0x00, 0xc0, 0xc0, 0x00, 0xc0, 0xc0, 0x00},
+      {2, 0x00, 0x00, 0xc0, 0xc0, 0x00, 0xc0, 0xc0, 0xc0},
       {4, 0x00, 0x00, 0x30, 0x60, 0xc0, 0x60, 0x30, 0x00},
       {5, 0x00, 0x00, 0x00, 0xf8, 0x00, 0xf8, 0x00, 0x00},
       {4, 0x00, 0x00, 0xc0, 0x60, 0x30, 0x60, 0xc0, 0x00},
@@ -130,7 +130,7 @@ namespace picosystem {
       {3, 0xc0, 0xc0, 0xe0, 0xc0, 0xc0, 0xc0, 0x60, 0x00},
       {5, 0x00, 0x00, 0xd8, 0xd8, 0xd8, 0xd8, 0x68, 0x00},
       {5, 0x00, 0x00, 0xd8, 0xd8, 0xd8, 0x70, 0x20, 0x00},
-      {6, 0x00, 0x00, 0xcc, 0xcc, 0xcc, 0xec, 0x5c, 0x00},
+      {7, 0x00, 0x00, 0xc6, 0xc6, 0xc6, 0xd6, 0x6c, 0x00},
       {6, 0x00, 0x00, 0xcc, 0x78, 0x30, 0x78, 0xcc, 0x00},
       {5, 0x00, 0x00, 0xd8, 0xd8, 0xd8, 0x78, 0x18, 0x70},
       {5, 0x00, 0x00, 0xf8, 0x30, 0x60, 0xc0, 0xf8, 0x00},

libraries/blend.cpp

@@ -52,7 +52,150 @@ namespace picosystem {
       // step destination and source
       pd++; so += ss;
     }
+  }
+
+  // compares source and destination RGB channels and picks the darker of the
+  // two. if there is global alpha the result is then blended with the
+  // destination.
+  void DARKEN(color_t *ps, uint32_t so, int32_t ss, color_t *pd, uint32_t c) {
+    while(c--) {
+      color_t s = *(ps + (so >> 16));
+      color_t d = *pd;
+
+      uint16_t sr = (s & 0x000f), sg = (s & 0xf000), sb = (s & 0x0f00);
+      uint16_t dr = (d & 0x000f), dg = (d & 0xf000), db = (d & 0x0f00);
+      uint16_t sa = (s & 0x00f0);
+
+      s = (sr < dr ? sr : dr) | (sg < dg ? sg : dg) | (sb < db ? sb : db) | sa;
+      ALPHA(&s, 0, 0, pd, 1);
+
+      // step destination and source
+      pd++; so += ss;
+    }
+  }
+
+  // compares source and destination RGB channels and picks the lighter of the
+  // two. if there is global alpha the result is then blended with the
+  // destination.
+  void LIGHTEN(color_t *ps, uint32_t so, int32_t ss, color_t *pd, uint32_t c) {
+    while(c--) {
+      color_t s = *(ps + (so >> 16));
+      color_t d = *pd;
+
+      uint16_t sr = (s & 0x000f), sg = (s & 0xf000), sb = (s & 0x0f00);
+      uint16_t dr = (d & 0x000f), dg = (d & 0xf000), db = (d & 0x0f00);
+      uint16_t sa = (s & 0x00f0);
+
+      s = (sr > dr ? sr : dr) | (sg > dg ? sg : dg) | (sb > db ? sb : db) | sa;
+      ALPHA(&s, 0, 0, pd, 1);
+
+      // step destination and source
+      pd++; so += ss;
+    }
+  }
+
+  // compares source and destination RGB channels and picks the lighter of the
+  // two. if there is global alpha the result is then blended with the
+  // destination.
+  void ADD(color_t *ps, uint32_t so, int32_t ss, color_t *pd, uint32_t c) {
+    while(c--) {
+      color_t s = *(ps + (so >> 16));
+      color_t d = *pd;
+
+      int32_t sr = (s & 0x000f), sg = (s & 0xf000), sb = (s & 0x0f00);
+      int32_t dr = (d & 0x000f), dg = (d & 0xf000), db = (d & 0x0f00);
+      int32_t sa = (s & 0x00f0);
+
+      dr += sr;
+      dg += sg;
+      db += sb;
+
+      dr = dr > 15 ? 15 : dr;
+      dg = dg > (15 << 12) ? (15 << 12) : dg;
+      db = db > (15 << 8) ? (15 << 8) : db;
+
+      s = dr | dg | db | sa;
+
+      ALPHA(&s, 0, 0, pd, 1);
+
+      // step destination and source
+      pd++; so += ss;
+    }
+  }
+
+  // compares source and destination RGB channels and picks the lighter of the
+  // two. if there is global alpha the result is then blended with the
+  // destination.
+  void SUBTRACT(color_t *ps, uint32_t so, int32_t ss, color_t *pd, uint32_t c) {
+    while(c--) {
+      color_t s = *(ps + (so >> 16));
+      color_t d = *pd;
+
+      int32_t sr = (s & 0x000f), sg = (s & 0xf000), sb = (s & 0x0f00);
+      int32_t dr = (d & 0x000f), dg = (d & 0xf000), db = (d & 0x0f00);
+      int32_t sa = (s & 0x00f0);
+
+      dr = dr > sr ? dr - sr : 0;
+      dg = dg > sg ? dg - sg : 0;
+      db = db > sb ? db - sb : 0;
+
+      s = dr | dg | db | sa;
+      ALPHA(&s, 0, 0, pd, 1);
+
+      // step destination and source
+      pd++; so += ss;
+    }
+  }
+
+  // compares source and destination RGB channels and picks the lighter of the
+  // two. if there is global alpha the result is then blended with the
+  // destination.
+  void MULTIPLY(color_t *ps, uint32_t so, int32_t ss, color_t *pd, uint32_t c) {
+    while(c--) {
+      color_t s = *(ps + (so >> 16));
+      color_t d = *pd;
+
+      int32_t sr = (s & 0x000f), sg = (s & 0xf000), sb = (s & 0x0f00);
+      int32_t dr = (d & 0x000f), dg = (d & 0xf000), db = (d & 0x0f00);
+      int32_t sa = (s & 0x00f0);
+
+      dr = (sr * dr) >> 4;
+      dg = (sg * dg) >> 18;
+      db = (sb * db) >> 12;
 
+      s = dr | dg | db | sa;
+      ALPHA(&s, 0, 0, pd, 1);
+
+      // step destination and source
+      pd++; so += ss;
+    }
+  }
+
+  uint32_t _hash(uint32_t v) {
+    int n = 4;
+    do {
+      v = ((v >> 8) ^ v) * 0xD2 + n;
+    } while(--n);
+    return v;
+  }
+  // performs a "fizzlefade" style effect by only copying the source pixel if
+  // the destination pointer address hashes to a value < source alpha
+  void DISSOLVE(color_t *ps, uint32_t so, int32_t ss, color_t *pd, uint32_t c) {
+    while(c--) {
+      color_t s = *(ps + (so >> 16));
+
+      int32_t sa = (s & 0x00f0) >> 4;
+
+      // create 4-bit hash of destination pointer...
+      int32_t h = _hash(int32_t(pd) >> 1) & 0x000f;
+      h = h == 0 ? 0 : h - 1;
+      if(h < sa) {
+        COPY(&s, 0, 0, pd, 1);
+      }
+
+      // step destination and source
+      pd++; so += ss;
+    }
   }
 
   // blends the source and destination

libraries/hardware.cpp

@@ -343,7 +343,7 @@ namespace picosystem {
       FRMCTR1   = 0xB1, FRMCTR2   = 0xB2, GMCTRP1   = 0xE0, GMCTRN1   = 0xE1,
       INVOFF    = 0x20, SLPOUT    = 0x11, DISPON    = 0x29, GAMSET    = 0x26,
       DISPOFF   = 0x28, RAMWR     = 0x2C, INVON     = 0x21, CASET     = 0x2A,
-      RASET     = 0x2B, STE       = 0x44
+      RASET     = 0x2B, STE       = 0x44, DGMEN     = 0xBA,
     };
 
     _screen_command(SWRESET);
@@ -352,7 +352,7 @@ namespace picosystem {
     _screen_command(TEON,      1, "\x00");
     _screen_command(FRMCTR2,   5, "\x0C\x0C\x00\x33\x33");
     _screen_command(COLMOD,    1, "\x03");
-    _screen_command(GAMSET,    1, "\x04");
+    _screen_command(GAMSET,    1, "\x01");
 
     _screen_command(GCTRL,     1, "\x14");
     _screen_command(VCOMS,     1, "\x25");

libraries/picosystem.hpp

@@ -147,6 +147,18 @@ namespace picosystem {
                 color_t* ps, uint32_t so, int32_t ss, color_t* pd, uint32_t c);
   void        PEN(
                 color_t* ps, uint32_t so, int32_t ss, color_t* pd, uint32_t c);
+  void        DARKEN(
+                color_t* ps, uint32_t so, int32_t ss, color_t* pd, uint32_t c);
+  void        LIGHTEN(
+                color_t* ps, uint32_t so, int32_t ss, color_t* pd, uint32_t c);
+  void        ADD(
+                color_t* ps, uint32_t so, int32_t ss, color_t* pd, uint32_t c);
+  void        SUBTRACT(
+                color_t* ps, uint32_t so, int32_t ss, color_t* pd, uint32_t c);
+  void        MULTIPLY(
+                color_t* ps, uint32_t so, int32_t ss, color_t* pd, uint32_t c);
+  void        DISSOLVE(
+                color_t* ps, uint32_t so, int32_t ss, color_t* pd, uint32_t c);
 
   // audio
   void        play(