speed up rendering by factor 1000

src/bin/main.rs

@@ -15,6 +15,9 @@ use base64::{Engine as _, engine::general_purpose};
 use display_interface_spi::SPIInterface;
 use embassy_executor::Spawner;
 use embassy_time::Timer;
+use display_interface_spi::SPIInterface;
+use embedded_graphics::{Drawable, geometry::Size, primitives::Rectangle};
+use embedded_graphics::Pixel;
 use embedded_graphics::mono_font::MonoTextStyle;
 use embedded_graphics::mono_font::ascii::FONT_6X10;
 use embedded_graphics::pixelcolor::Rgb565;
@@ -440,8 +443,7 @@ where
             // Bitwise operations are slightly faster than division/modulo
             let byte_index = pixel_index >> 1;
             let pixel_byte = sprite[byte_index];
-
+            let color_index = if pixel_index.is_multiple_of(2) {
-            let color_index = if pixel_index & 1 == 0 {
                 (pixel_byte >> 4) & 0x0F
             } else {
                 pixel_byte & 0x0F
@@ -449,24 +451,13 @@ where
 
             let color = palette565[color_index as usize];
 
-            let start_x = (x * scale) as i32;
+            let width = u32::try_from(end_x - start_x).unwrap();
-            let start_y = (y * scale) as i32;
+            let height = u32::try_from(end_y - start_y).unwrap();
-            let end_x = core::cmp::min(start_x + scale as i32, target_width as i32);
-            let end_y = core::cmp::min(start_y + scale as i32, target_width as i32);
 
-            let width = (end_x - start_x) as u32;
+            let area = Rectangle::new(Point::new(start_x.try_into().unwrap(), start_y.try_into().unwrap()), Size::new(width, height));
-            let height = (end_y - start_y) as u32;
 
-            if width == 0 || height == 0 {
-                continue;
-            }
 
-            // OPTIMIZATION 2: Draw a rectangle block.
+            let _ = ili9341.fill_solid(&area, color);
-            // The display driver sets the SPI window ONCE per block.
-            let rect = Rectangle::new(Point::new(start_x, start_y), Size::new(width, height));
-            let style = PrimitiveStyle::with_fill(color);
-
-            let _ = rect.into_styled(style).draw(ili9341);
         }
     }
 }
@@ -630,10 +621,14 @@ async fn main(spawner: Spawner) {
         esp_hal::interrupt::software::SoftwareInterruptControl::new(peripherals.SW_INTERRUPT);
     esp_rtos::start(timg0.timer0, sw_interrupt.software_interrupt0);
 
+
+    let freq = Rate::from_khz(60_000);
+    info!("Display freq: {freq}");
+
     let spi_bus = Spi::new(
         peripherals.SPI2,
         Config::default()
-            .with_frequency(Rate::from_mhz(40))
+            .with_frequency(freq)
             .with_mode(Mode::_0),
     )
     .unwrap()