PicoGraphics: Add layer support to PicoVector tile renderer.

pimoroni · Oct 8, 2024 · 2d556d1 · 2d556d1
1 parent 5a8b946
commit 2d556d1
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Showing 2 changed files with 33 additions and 14 deletions.
diff --git a/libraries/pico_graphics/pico_graphics_pen_rgb332.cpp b/libraries/pico_graphics/pico_graphics_pen_rgb332.cpp
@@ -99,7 +99,7 @@ namespace pimoroni {
  // Treat our void* frame_buffer as uint8_t
  uint8_t *src = (uint8_t *)frame_buffer;
 
-  if(this->layers > 1) {
+ if(this->layers > 1) {
  // The size of a single layer
  uint offset = this->bounds.w * this->bounds.h;
 
@@ -148,14 +148,23 @@ namespace pimoroni {
  bool PicoGraphics_PenRGB332::render_tile(const Tile *tile) {
  for(int y = 0; y < tile->h; y++) {
  uint8_t *palpha = &tile->data[(y * tile->stride)];
- uint8_t *pdest = &((uint8_t *)frame_buffer)[tile->x + ((tile->y + y) * bounds.w)];
+
+ uint8_t *p_dest = &((uint8_t *)frame_buffer)[tile->x + ((tile->y + y) * bounds.w)];
+ p_dest += this->layer_offset;
+
+ uint8_t *p_layer0 = &((uint8_t *)frame_buffer)[tile->x + ((tile->y + y) * bounds.w)];
+
+
  for(int x = 0; x < tile->w; x++) {
  uint8_t alpha = *palpha;
- uint8_t dest = *pdest;
+ uint8_t dest = *p_dest;
+ if(dest == 0) {
+ dest = *p_layer0;
+ }
 
  // TODO: Try to alpha blend RGB332... somewhat?
  if(alpha == 255) {
- *pdest = color;
+ *p_dest = color;
  }else if(alpha == 0) {
  }else{
  // blend tha pixel
@@ -172,10 +181,10 @@ namespace pimoroni {
  uint8_t b = ((sb * alpha) + (db * (255 - alpha))) >> 8;
 
  // recombine the channels
- *pdest = (r << 5) | (g << 2) | (b);
+ *p_dest = (r << 5) | (g << 2) | (b);
  }
 
- pdest++;
+ p_dest++;
  palpha++;
  }
  }

diff --git a/libraries/pico_graphics/pico_graphics_pen_rgb565.cpp b/libraries/pico_graphics/pico_graphics_pen_rgb565.cpp
@@ -64,6 +64,7 @@ namespace pimoroni {
  if(!bounds.contains(p)) return;
 
  uint16_t *buf = (uint16_t *)frame_buffer;
+ buf += this->layer_offset;
 
  RGB565 blended = RGB(buf[p.y * bounds.w + p.x]).blend(RGB(color), a).to_rgb565();
 
@@ -72,14 +73,22 @@ namespace pimoroni {
 
  bool PicoGraphics_PenRGB565::render_tile(const Tile *tile) {
  for(int y = 0; y < tile->h; y++) {
- uint8_t *palpha = &tile->data[(y * tile->stride)];
- uint16_t *pdest = &((uint16_t *)frame_buffer)[tile->x + ((tile->y + y) * bounds.w)];
+ uint8_t *p_alpha = &tile->data[(y * tile->stride)];
+
+ uint16_t *p_dest = &((uint16_t *)frame_buffer)[tile->x + ((tile->y + y) * bounds.w)];
+ p_dest += this->layer_offset;
+
+ uint16_t *p_layer0 = &((uint16_t *)frame_buffer)[tile->x + ((tile->y + y) * bounds.w)];
+
  for(int x = 0; x < tile->w; x++) {
- uint16_t dest = *pdest;
- uint8_t alpha = *palpha;
+ uint16_t dest = *p_dest;
+ if(dest == 0) {
+ dest = *p_layer0;
+ }
+ uint8_t alpha = *p_alpha;
 
  if(alpha == 255) {
- *pdest = color;
+ *p_dest = color;
  }else if(alpha == 0) {
  }else{
  // blend tha pixel
@@ -96,11 +105,12 @@ namespace pimoroni {
  uint8_t b = ((sb * alpha) + (db * (255 - alpha))) >> 8;
 
  // recombine the channels
- *pdest = __builtin_bswap16((r << 11) | (g << 5) | (b));
+ *p_dest = __builtin_bswap16((r << 11) | (g << 5) | (b));
  }
 
- pdest++;
- palpha++;
+ p_layer0++;
+ p_dest++;
+ p_alpha++;
  }
  }