PicoGraphics: Support multiple layers in more types.

pimoroni · Oct 24, 2024 · be24eb5 · be24eb5
1 parent 5e0682b
commit be24eb5
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Showing 9 changed files with 158 additions and 67 deletions.
diff --git a/drivers/st7735/st7735.cpp b/drivers/st7735/st7735.cpp
@@ -165,17 +165,21 @@ namespace pimoroni {
 
   // Native 16-bit framebuffer update
   void ST7735::update(PicoGraphics *graphics) {
-    command(reg::RAMWR);
-    gpio_put(dc, 1); // data mode
-    gpio_put(cs, 0);
+    if(graphics->pen_type == PicoGraphics::PEN_RGB565 && graphics->layers == 1) {
+      command(reg::RAMWR, width * height * sizeof(uint16_t), (const char*)graphics->frame_buffer);
+    } else {
+      command(reg::RAMWR);
+      gpio_put(dc, 1); // data mode
+      gpio_put(cs, 0);
 
-    graphics->frame_convert(PicoGraphics::PEN_RGB565, [this](void *data, size_t length) {
-      if (length > 0) {
-        spi_write_blocking(spi, (const uint8_t*)data, length);
-      }
-    });
+      graphics->frame_convert(PicoGraphics::PEN_RGB565, [this](void *data, size_t length) {
+        if (length > 0) {
+          spi_write_blocking(spi, (const uint8_t*)data, length);
+        }
+      });
 
-    gpio_put(cs, 1);
+      gpio_put(cs, 1);
+    }
   }
 
   void ST7735::set_backlight(uint8_t brightness) {

diff --git a/drivers/st7789/st7789.cpp b/drivers/st7789/st7789.cpp
@@ -282,26 +282,30 @@ namespace pimoroni {
   void ST7789::update(PicoGraphics *graphics) {
     uint8_t cmd = reg::RAMWR;
 
-    gpio_put(dc, 0); // command mode
-    gpio_put(cs, 0);
-    if(spi) { // SPI Bus
-      spi_write_blocking(spi, &cmd, 1);
-    } else { // Parallel Bus
-      write_blocking_parallel(&cmd, 1);
-    }
+    if(graphics->pen_type == PicoGraphics::PEN_RGB565 && graphics->layers == 1) { // Display buffer is screen native
+      command(cmd, width * height * sizeof(uint16_t), (const char*)graphics->frame_buffer);
+    } else {
+      gpio_put(dc, 0); // command mode
+      gpio_put(cs, 0);
+      if(spi) { // SPI Bus
+        spi_write_blocking(spi, &cmd, 1);
+      } else { // Parallel Bus
+        write_blocking_parallel(&cmd, 1);
+      }
 
-    gpio_put(dc, 1); // data mode
+      gpio_put(dc, 1); // data mode
 
-    graphics->frame_convert(PicoGraphics::PEN_RGB565, [this](void *data, size_t length) {
-      if (length > 0) {
-        write_blocking_dma((const uint8_t*)data, length);
-      }
-      else {
-        dma_channel_wait_for_finish_blocking(st_dma);
-      }
-    });
+      graphics->frame_convert(PicoGraphics::PEN_RGB565, [this](void *data, size_t length) {
+        if (length > 0) {
+          write_blocking_dma((const uint8_t*)data, length);
+        }
+        else {
+          dma_channel_wait_for_finish_blocking(st_dma);
+        }
+      });
 
-    gpio_put(cs, 1);
+      gpio_put(cs, 1);
+    }
   }
 
   void ST7789::set_backlight(uint8_t brightness) {

diff --git a/libraries/pico_graphics/pico_graphics.cpp b/libraries/pico_graphics/pico_graphics.cpp
@@ -21,6 +21,7 @@ namespace pimoroni {
 
   void PicoGraphics::set_layer(uint l) {
     this->layer = l;
+    this->layer_offset = this->bounds.w * this->bounds.h * l;
   };
   uint PicoGraphics::get_layer() {
     return this->layer;

diff --git a/libraries/pico_graphics/pico_graphics.hpp b/libraries/pico_graphics/pico_graphics.hpp
@@ -79,6 +79,7 @@ namespace pimoroni {
       }
   }
 
+    constexpr operator bool() {return r || g || b;};
     constexpr RGB  operator+ (const RGB& c) const {return RGB(r + c.r, g + c.g, b + c.b);}
     constexpr RGB& operator+=(const RGB& c) {r += c.r; g += c.g; b += c.b; return *this;}
     constexpr RGB& operator-=(const RGB& c) {r -= c.r; g -= c.g; b -= c.b; return *this;}
@@ -228,6 +229,7 @@ namespace pimoroni {
 
     uint layers = 1;
     uint layer = 0;
+    uint layer_offset = 0;
 
     typedef std::function<void(void *data, size_t length)> conversion_callback_func;
     typedef std::function<RGB565()> next_pixel_func;

diff --git a/libraries/pico_graphics/pico_graphics_pen_p4.cpp b/libraries/pico_graphics/pico_graphics_pen_p4.cpp
@@ -59,6 +59,7 @@ namespace pimoroni {
 
         // pointer to byte in framebuffer that contains this pixel
         uint8_t *buf = (uint8_t *)frame_buffer;
+        buf += this->layer_offset / 2;
         uint8_t *f = &buf[i / 2];
 
         uint8_t  o = (~i & 0b1) * 4;   // bit offset within byte
@@ -74,6 +75,7 @@ namespace pimoroni {
 
         // pointer to byte in framebuffer that contains this pixel
         uint8_t *buf = (uint8_t *)frame_buffer;
+        buf += this->layer_offset / 2;
         uint8_t *f = &buf[i / 2];
 
         // doubled up color value, so the color is stored in both nibbles
@@ -144,16 +146,39 @@ namespace pimoroni {
             uint8_t *src = (uint8_t *)frame_buffer;
             uint8_t o = 4;
 
-            frame_convert_rgb565(callback, [&]() {
-                uint8_t c = *src;
-                uint8_t b = (c >> o) & 0xf; // bit value shifted to position
-
-                // Increment to next 4-bit entry 
-                o ^= 4;
-                if (o != 0) ++src;
-
-                return cache[b];
-            });
+            if(this->layers > 1) {
+
+                uint offset = this->bounds.w * this->bounds.h / 2;
+
+                frame_convert_rgb565(callback, [&]() {
+                    uint8_t b = 0;
+
+                    // Iterate through layers in reverse order
+                    // Return the first nonzero (not transparent) pixel
+                    for(auto layer = this->layers; layer > 0; layer--) {
+                        uint8_t c = *(src + offset * (layer - 1));
+                        b = (c >> o) & 0xf; // bit value shifted to position
+                        if (b) break;
+                    }
+
+                    // Increment to next 4-bit entry 
+                    o ^= 4;
+                    if (o != 0) src++;
+
+                    return cache[b];
+                });
+            } else {
+                frame_convert_rgb565(callback, [&]() {
+                    uint8_t c = *src;
+                    uint8_t b = (c >> o) & 0xf; // bit value shifted to position
+
+                    // Increment to next 4-bit entry 
+                    o ^= 4;
+                    if (o != 0) ++src;
+
+                    return cache[b];
+                });
+            }
         }
     }
 }
diff --git a/libraries/pico_graphics/pico_graphics_pen_p8.cpp b/libraries/pico_graphics/pico_graphics_pen_p8.cpp
@@ -51,12 +51,14 @@ namespace pimoroni {
     }
     void PicoGraphics_PenP8::set_pixel(const Point &p) {
         uint8_t *buf = (uint8_t *)frame_buffer;
+        buf += this->layer_offset;
         buf[p.y * bounds.w + p.x] = color;
     }
 
     void PicoGraphics_PenP8::set_pixel_span(const Point &p, uint l) {
         // pointer to byte in framebuffer that contains this pixel
         uint8_t *buf = (uint8_t *)frame_buffer;
+        buf += this->layer_offset;
         buf = &buf[p.y * bounds.w + p.x];
 
         while(l--) {
@@ -103,26 +105,70 @@ namespace pimoroni {
     }
 
     void PicoGraphics_PenP8::frame_convert(PenType type, conversion_callback_func callback) {
-        if(type == PEN_RGB565) {
-            // Cache the RGB888 palette as RGB565
-            RGB565 cache[palette_size];
-            for(auto i = 0u; i < palette_size; i++) {
-                cache[i] = palette[i].to_rgb565();
-            }
+        // Treat our void* frame_buffer as uint8_t
+        uint8_t *src = (uint8_t *)frame_buffer;
+
+        if(layers > 1) {
+            // The size of a single layer
+            uint offset = this->bounds.w * this->bounds.h;
+
+            if(type == PEN_RGB565) {
+                // Cache the RGB888 palette as RGB565
+                RGB565 cache[palette_size];
+                for(auto i = 0u; i < palette_size; i++) {
+                    cache[i] = palette[i].to_rgb565();
+                }
+
+                frame_convert_rgb565(callback, [&]() {
+                    // Check the *palette* index, rather than the colour
+                    // Thus palette entry 0 is *always* transparent
+                    uint8_t c = 0;
+
+                    // Iterate through layers in reverse order
+                    // Return the first nonzero (not transparent) pixel
+                    for(auto layer = this->layers; layer > 0; layer--) {
+                        c = *(src + offset * (layer - 1));
+                        if (c) break;
+                    }
 
-            // Treat our void* frame_buffer as uint8_t
-            uint8_t *src = (uint8_t *)frame_buffer;
+                    src++;
 
-            frame_convert_rgb565(callback, [&]() {
-                return cache[*src++];
-            });
-        } else if (type == PEN_RGB888) {
-            // Treat our void* frame_buffer as uint8_t
-            uint8_t *src = (uint8_t *)frame_buffer;
+                    return cache[c];
+                });
+            } else if (type == PEN_RGB888) {
+                frame_convert_rgb888(callback, [&]() {
+                    // Check the *palette* index, rather than the colour
+                    // Thus palette entry 0 is *always* transparent
+                    uint8_t c = 0;
 
-            frame_convert_rgb888(callback, [&]() {
-                return palette[*src++].to_rgb888();
-            });
+                    // Iterate through layers in reverse order
+                    // Return the first nonzero (not transparent) pixel
+                    for(auto layer = this->layers; layer > 0; layer--) {
+                        c = *(src + offset * (layer - 1));
+                        if (c) break;
+                    }
+
+                    src++;
+
+                    return palette[c].to_rgb888();
+                });
+            }
+        } else {
+            if(type == PEN_RGB565) {
+                // Cache the RGB888 palette as RGB565
+                RGB565 cache[palette_size];
+                for(auto i = 0u; i < palette_size; i++) {
+                    cache[i] = palette[i].to_rgb565();
+                }
+
+                frame_convert_rgb565(callback, [&]() {
+                    return cache[*src++];
+                });
+            } else if (type == PEN_RGB888) {
+                frame_convert_rgb888(callback, [&]() {
+                    return palette[*src++].to_rgb888();
+                });
+            }
         }
     }
 }
diff --git a/libraries/pico_graphics/pico_graphics_pen_rgb332.cpp b/libraries/pico_graphics/pico_graphics_pen_rgb332.cpp
@@ -23,13 +23,13 @@ namespace pimoroni {
     }
     void PicoGraphics_PenRGB332::set_pixel(const Point &p) {
         uint8_t *buf = (uint8_t *)frame_buffer;
-        buf += buffer_size(this->bounds.w, this->bounds.h) * layer;
+        buf += this->layer_offset;
         buf[p.y * bounds.w + p.x] = color;
     }
     void PicoGraphics_PenRGB332::set_pixel_span(const Point &p, uint l) {
         // pointer to byte in framebuffer that contains this pixel
         uint8_t *buf = (uint8_t *)frame_buffer;
-        buf += buffer_size(this->bounds.w, this->bounds.h) * layer;
+        buf += this->layer_offset;
         buf += p.y * bounds.w + p.x;
 
         while(l--) {
@@ -40,7 +40,7 @@ namespace pimoroni {
         if(!bounds.contains(p)) return;
 
         uint8_t *buf = (uint8_t *)frame_buffer;
-        buf += buffer_size(this->bounds.w, this->bounds.h) * layer;
+        buf += this->layer_offset;
 
         RGB332 blended = RGB(buf[p.y * bounds.w + p.x]).blend(RGB(color), a).to_rgb332();
 
@@ -99,14 +99,23 @@ namespace pimoroni {
             // Treat our void* frame_buffer as uint8_t
             uint8_t *src = (uint8_t *)frame_buffer;
 
-            if(this->layers > 1) {
-                // Assume only two layers for now
-                uint8_t *src_layer2 = src + buffer_size(this->bounds.w, this->bounds.h);
+                if(this->layers > 1) {
+                // The size of a single layer
+                uint offset = this->bounds.w * this->bounds.h;
 
                 frame_convert_rgb565(callback, [&]() {
-                    RGB565 c1 = rgb332_to_rgb565_lut[*src++];
-                    RGB565 c2 = rgb332_to_rgb565_lut[*src_layer2++];
-                    return c2 ? c2 : c1;
+                    uint8_t c = 0;
+
+                    // Iterate through layers in reverse order
+                    // Return the first nonzero (not transparent) pixel
+                    for(auto layer = this->layers; layer > 0; layer--) {
+                        c = *(src + offset * (layer - 1));
+                        if (c) break;
+                    }
+
+                    src++;
+
+                    return rgb332_to_rgb565_lut[c];
                 });
             } else {
                 frame_convert_rgb565(callback, [&]() {

diff --git a/libraries/pico_graphics/pico_graphics_pen_rgb565.cpp b/libraries/pico_graphics/pico_graphics_pen_rgb565.cpp
@@ -24,14 +24,14 @@ namespace pimoroni {
     void PicoGraphics_PenRGB565::set_pixel(const Point &p) {
         uint16_t *buf = (uint16_t *)frame_buffer;
         // We can't use buffer_size because our pointer is uint16_t
-        buf += this->bounds.w * this->bounds.h * layer;
+        buf += this->layer_offset;
         buf[p.y * bounds.w + p.x] = color;
     }
     void PicoGraphics_PenRGB565::set_pixel_span(const Point &p, uint l) {
         // pointer to byte in framebuffer that contains this pixel
         uint16_t *buf = (uint16_t *)frame_buffer;
         // We can't use buffer_size because our pointer is uint16_t
-        buf += this->bounds.w * this->bounds.h * layer;
+        buf += this->layer_offset;
         buf = &buf[p.y * bounds.w + p.x];
 
         while(l--) {
@@ -45,10 +45,8 @@ namespace pimoroni {
 
             if(layers > 1) {
                 // Assume only two layers for now
-                uint16_t *src_layer2 = src;
-
                 // We can't use buffer_size because our pointer is uint16_t
-                src_layer2 += this->bounds.w * this->bounds.h * layer;
+                uint16_t *src_layer2 = src + this->bounds.w * this->bounds.h;
 
                 frame_convert_rgb565(callback, [&]() {
                     RGB565 c1 = *src++;

diff --git a/libraries/pico_graphics/pico_graphics_pen_rgb888.cpp b/libraries/pico_graphics/pico_graphics_pen_rgb888.cpp
@@ -23,11 +23,13 @@ namespace pimoroni {
     }
     void PicoGraphics_PenRGB888::set_pixel(const Point &p) {
         uint32_t *buf = (uint32_t *)frame_buffer;
+        buf += this->layer_offset;
         buf[p.y * bounds.w + p.x] = color;
     }
     void PicoGraphics_PenRGB888::set_pixel_span(const Point &p, uint l) {
         // pointer to byte in framebuffer that contains this pixel
         uint32_t *buf = (uint32_t *)frame_buffer;
+        buf += this->layer_offset;
         buf = &buf[p.y * bounds.w + p.x];
 
         while(l--) {