[QP] Add RGB565 surface. Docs clarification, cleanup, tabsification, and reordering. (#18396)

3 files changed, 320 insertions, 3 deletions

diff --git a/drivers/painter/generic/qp_rgb565_surface.c b/drivers/painter/generic/qp_rgb565_surface.c
new file mode 100644
index 0000000000..c4de336535
--- /dev/null
+++ b/drivers/painter/generic/qp_rgb565_surface.c
@@ -0,0 +1,277 @@
+// Copyright 2022 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include "color.h"
+#include "qp_rgb565_surface.h"
+#include "qp_draw.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Common
+
+// Device definition
+typedef struct rgb565_surface_painter_device_t {
+    struct painter_driver_t base; // must be first, so it can be cast to/from the painter_device_t* type
+
+    // The target buffer
+    uint16_t *buffer;
+
+    // Manually manage the viewport for streaming pixel data to the display
+    uint16_t viewport_l;
+    uint16_t viewport_t;
+    uint16_t viewport_r;
+    uint16_t viewport_b;
+
+    // Current write location to the display when streaming pixel data
+    uint16_t pixdata_x;
+    uint16_t pixdata_y;
+
+    // Maintain a dirty region so we can stream only what we need
+    bool     is_dirty;
+    uint16_t dirty_l;
+    uint16_t dirty_t;
+    uint16_t dirty_r;
+    uint16_t dirty_b;
+
+} rgb565_surface_painter_device_t;
+
+// Driver storage
+rgb565_surface_painter_device_t surface_drivers[RGB565_SURFACE_NUM_DEVICES] = {0};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Helpers
+
+static inline void increment_pixdata_location(rgb565_surface_painter_device_t *surface) {
+    // Increment the X-position
+    surface->pixdata_x++;
+
+    // If the x-coord has gone past the right-side edge, loop it back around and increment the y-coord
+    if (surface->pixdata_x > surface->viewport_r) {
+        surface->pixdata_x = surface->viewport_l;
+        surface->pixdata_y++;
+    }
+
+    // If the y-coord has gone past the bottom, loop it back to the top
+    if (surface->pixdata_y > surface->viewport_b) {
+        surface->pixdata_y = surface->viewport_t;
+    }
+}
+
+static inline void setpixel(rgb565_surface_painter_device_t *surface, uint16_t x, uint16_t y, uint16_t rgb565) {
+    // Skip messing with the dirty info if the original value already matches
+    if (surface->buffer[y * surface->base.panel_width + x] != rgb565) {
+        // Maintain dirty region
+        if (surface->dirty_l > x) {
+            surface->dirty_l = x;
+        }
+        if (surface->dirty_r < x) {
+            surface->dirty_r = x;
+        }
+        if (surface->dirty_t > y) {
+            surface->dirty_t = y;
+        }
+        if (surface->dirty_b < y) {
+            surface->dirty_b = y;
+        }
+
+        // Always dirty after a setpixel
+        surface->is_dirty = true;
+
+        // Update the pixel data in the buffer
+        surface->buffer[y * surface->base.panel_width + x] = rgb565;
+    }
+}
+
+static inline void append_pixel(rgb565_surface_painter_device_t *surface, uint16_t rgb565) {
+    setpixel(surface, surface->pixdata_x, surface->pixdata_y, rgb565);
+    increment_pixdata_location(surface);
+}
+
+static inline void stream_pixdata(rgb565_surface_painter_device_t *surface, const uint16_t *data, uint32_t native_pixel_count) {
+    for (uint32_t pixel_counter = 0; pixel_counter < native_pixel_count; ++pixel_counter) {
+        append_pixel(surface, data[pixel_counter]);
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Driver vtable
+
+static bool qp_rgb565_surface_init(painter_device_t device, painter_rotation_t rotation) {
+    struct painter_driver_t *        driver  = (struct painter_driver_t *)device;
+    rgb565_surface_painter_device_t *surface = (rgb565_surface_painter_device_t *)driver;
+    memset(surface->buffer, 0, driver->panel_width * driver->panel_height * driver->native_bits_per_pixel / 8);
+    return true;
+}
+
+static bool qp_rgb565_surface_power(painter_device_t device, bool power_on) {
+    // No-op.
+    return true;
+}
+
+static bool qp_rgb565_surface_clear(painter_device_t device) {
+    struct painter_driver_t *driver = (struct painter_driver_t *)device;
+    driver->driver_vtable->init(device, driver->rotation); // Re-init the surface
+    return true;
+}
+
+static bool qp_rgb565_surface_flush(painter_device_t device) {
+    struct painter_driver_t *        driver  = (struct painter_driver_t *)device;
+    rgb565_surface_painter_device_t *surface = (rgb565_surface_painter_device_t *)driver;
+    surface->dirty_l = surface->dirty_t = UINT16_MAX;
+    surface->dirty_r = surface->dirty_b = 0;
+    surface->is_dirty                   = false;
+    return true;
+}
+
+static bool qp_rgb565_surface_viewport(painter_device_t device, uint16_t left, uint16_t top, uint16_t right, uint16_t bottom) {
+    struct painter_driver_t *        driver  = (struct painter_driver_t *)device;
+    rgb565_surface_painter_device_t *surface = (rgb565_surface_painter_device_t *)driver;
+
+    // Set the viewport locations
+    surface->viewport_l = left;
+    surface->viewport_t = top;
+    surface->viewport_r = right;
+    surface->viewport_b = bottom;
+
+    // Reset the write location to the top left
+    surface->pixdata_x = left;
+    surface->pixdata_y = top;
+    return true;
+}
+
+// Stream pixel data to the current write position in GRAM
+static bool qp_rgb565_surface_pixdata(painter_device_t device, const void *pixel_data, uint32_t native_pixel_count) {
+    struct painter_driver_t *        driver  = (struct painter_driver_t *)device;
+    rgb565_surface_painter_device_t *surface = (rgb565_surface_painter_device_t *)driver;
+    stream_pixdata(surface, (const uint16_t *)pixel_data, native_pixel_count);
+    return true;
+}
+
+// Pixel colour conversion
+static bool qp_rgb565_surface_palette_convert_rgb565_swapped(painter_device_t device, int16_t palette_size, qp_pixel_t *palette) {
+    for (int16_t i = 0; i < palette_size; ++i) {
+        RGB      rgb      = hsv_to_rgb_nocie((HSV){palette[i].hsv888.h, palette[i].hsv888.s, palette[i].hsv888.v});
+        uint16_t rgb565   = (((uint16_t)rgb.r) >> 3) << 11 | (((uint16_t)rgb.g) >> 2) << 5 | (((uint16_t)rgb.b) >> 3);
+        palette[i].rgb565 = __builtin_bswap16(rgb565);
+    }
+    return true;
+}
+
+// Append pixels to the target location, keyed by the pixel index
+static bool qp_rgb565_surface_append_pixels_rgb565(painter_device_t device, uint8_t *target_buffer, qp_pixel_t *palette, uint32_t pixel_offset, uint32_t pixel_count, uint8_t *palette_indices) {
+    uint16_t *buf = (uint16_t *)target_buffer;
+    for (uint32_t i = 0; i < pixel_count; ++i) {
+        buf[pixel_offset + i] = palette[palette_indices[i]].rgb565;
+    }
+    return true;
+}
+
+const struct painter_driver_vtable_t rgb565_surface_driver_vtable = {
+    .init            = qp_rgb565_surface_init,
+    .power           = qp_rgb565_surface_power,
+    .clear           = qp_rgb565_surface_clear,
+    .flush           = qp_rgb565_surface_flush,
+    .pixdata         = qp_rgb565_surface_pixdata,
+    .viewport        = qp_rgb565_surface_viewport,
+    .palette_convert = qp_rgb565_surface_palette_convert_rgb565_swapped,
+    .append_pixels   = qp_rgb565_surface_append_pixels_rgb565,
+};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Comms vtable
+
+static bool qp_rgb565_surface_comms_init(painter_device_t device) {
+    // No-op.
+    return true;
+}
+static bool qp_rgb565_surface_comms_start(painter_device_t device) {
+    // No-op.
+    return true;
+}
+static void qp_rgb565_surface_comms_stop(painter_device_t device) {
+    // No-op.
+}
+uint32_t qp_rgb565_surface_comms_send(painter_device_t device, const void *data, uint32_t byte_count) {
+    // No-op.
+    return byte_count;
+}
+
+struct painter_comms_vtable_t rgb565_surface_driver_comms_vtable = {
+    // These are all effective no-op's because they're not actually needed.
+    .comms_init  = qp_rgb565_surface_comms_init,
+    .comms_start = qp_rgb565_surface_comms_start,
+    .comms_stop  = qp_rgb565_surface_comms_stop,
+    .comms_send  = qp_rgb565_surface_comms_send};
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Factory function for creating a handle to an rgb565 surface
+
+painter_device_t qp_rgb565_make_surface(uint16_t panel_width, uint16_t panel_height, void *buffer) {
+    for (uint32_t i = 0; i < RGB565_SURFACE_NUM_DEVICES; ++i) {
+        rgb565_surface_painter_device_t *driver = &surface_drivers[i];
+        if (!driver->base.driver_vtable) {
+            driver->base.driver_vtable         = &rgb565_surface_driver_vtable;
+            driver->base.comms_vtable          = &rgb565_surface_driver_comms_vtable;
+            driver->base.native_bits_per_pixel = 16; // RGB565
+            driver->base.panel_width           = panel_width;
+            driver->base.panel_height          = panel_height;
+            driver->base.rotation              = QP_ROTATION_0;
+            driver->base.offset_x              = 0;
+            driver->base.offset_y              = 0;
+            driver->buffer                     = (uint16_t *)buffer;
+            return (painter_device_t)driver;
+        }
+    }
+    return NULL;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Drawing routine to copy out the dirty region and send it to another device
+
+bool qp_rgb565_surface_draw(painter_device_t surface, painter_device_t display, uint16_t x, uint16_t y) {
+    struct painter_driver_t *        surface_driver = (struct painter_driver_t *)surface;
+    rgb565_surface_painter_device_t *surface_handle = (rgb565_surface_painter_device_t *)surface_driver;
+
+    // If we're not dirty... we're done.
+    if (!surface_handle->is_dirty) {
+        return true;
+    }
+
+    // Set the target drawing area
+    bool ok = qp_viewport(display, x + surface_handle->dirty_l, y + surface_handle->dirty_t, x + surface_handle->dirty_r, y + surface_handle->dirty_b);
+    if (!ok) {
+        return false;
+    }
+
+    // Housekeeping of the amount of pixels to transfer
+    uint32_t  total_pixel_count = QUANTUM_PAINTER_PIXDATA_BUFFER_SIZE / sizeof(uint16_t);
+    uint32_t  pixel_counter     = 0;
+    uint16_t *target_buffer     = (uint16_t *)qp_internal_global_pixdata_buffer;
+
+    // Fill the global pixdata area so that we can start transferring to the panel
+    for (uint16_t y = surface_handle->dirty_t; y <= surface_handle->dirty_b; ++y) {
+        for (uint16_t x = surface_handle->dirty_l; x <= surface_handle->dirty_r; ++x) {
+            // Update the target buffer
+            target_buffer[pixel_counter++] = surface_handle->buffer[y * surface_handle->base.panel_width + x];
+
+            // If we've accumulated enough data, send it
+            if (pixel_counter == total_pixel_count) {
+                ok = qp_pixdata(display, qp_internal_global_pixdata_buffer, pixel_counter);
+                if (!ok) {
+                    return false;
+                }
+                // Reset the counter
+                pixel_counter = 0;
+            }
+        }
+    }
+
+    // If there's any leftover data, send it
+    if (pixel_counter > 0) {
+        ok = qp_pixdata(display, qp_internal_global_pixdata_buffer, pixel_counter);
+        if (!ok) {
+            return false;
+        }
+    }
+
+    // Clear the dirty info for the surface
+    return qp_flush(surface);
+}
diff --git a/drivers/painter/generic/qp_rgb565_surface.h b/drivers/painter/generic/qp_rgb565_surface.h
new file mode 100644
index 0000000000..19e919bb91
--- /dev/null
+++ b/drivers/painter/generic/qp_rgb565_surface.h
@@ -0,0 +1,42 @@
+// Copyright 2022 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+#include "qp_internal.h"
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Quantum Painter RGB565 surface configurables (add to your keyboard's config.h)
+
+#ifndef RGB565_SURFACE_NUM_DEVICES
+/**
+ * @def This controls the maximum number of surface devices that Quantum Painter can use at any one time.
+ *      Increasing this number allows for multiple framebuffers to be used. Each requires its own RAM allocation.
+ */
+#    define RGB565_SURFACE_NUM_DEVICES 1
+#endif
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Forward declarations
+
+#ifdef QUANTUM_PAINTER_RGB565_SURFACE_ENABLE
+/**
+ * Factory method for an RGB565 surface (aka framebuffer).
+ *
+ * @param panel_width[in] the width of the display panel
+ * @param panel_height[in] the height of the display panel
+ * @param buffer[in] pointer to a preallocated buffer of size `(sizeof(uint16_t) * panel_width * panel_height)`
+ * @return the device handle used with all drawing routines in Quantum Painter
+ */
+painter_device_t qp_rgb565_make_surface(uint16_t panel_width, uint16_t panel_height, void *buffer);
+
+/**
+ * Helper method to draw the dirty contents of the framebuffer to the target device.
+ *
+ * After successful completion, the dirty area is reset.
+ *
+ * @param surface[in] the surface to copy from
+ * @param display[in] the display to copy into
+ * @param x[in] the x-location of the original position of the framebuffer
+ * @param y[in] the y-location of the original position of the framebuffer
+ * @return whether the draw operation completed successfully
+ */
+bool qp_rgb565_surface_draw(painter_device_t surface, painter_device_t display, uint16_t x, uint16_t y);
+#endif // QUANTUM_PAINTER_RGB565_SURFACE_ENABLE
diff --git a/drivers/painter/tft_panel/qp_tft_panel.c b/drivers/painter/tft_panel/qp_tft_panel.c
index ad83b6c792..e7c744ab34 100644
--- a/drivers/painter/tft_panel/qp_tft_panel.c
+++ b/drivers/painter/tft_panel/qp_tft_panel.c
@@ -7,8 +7,6 @@
 #include "qp_draw.h"
 #include "qp_tft_panel.h"
 
-#define BYTE_SWAP(x) (((((uint16_t)(x)) >> 8) & 0x00FF) | ((((uint16_t)(x)) << 8) & 0xFF00))
-
 ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
 // Quantum Painter API implementations
 
@@ -94,7 +92,7 @@ bool qp_tft_panel_palette_convert_rgb565_swapped(painter_device_t device, int16_
     for (int16_t i = 0; i < palette_size; ++i) {
         RGB      rgb      = hsv_to_rgb_nocie((HSV){palette[i].hsv888.h, palette[i].hsv888.s, palette[i].hsv888.v});
         uint16_t rgb565   = (((uint16_t)rgb.r) >> 3) << 11 | (((uint16_t)rgb.g) >> 2) << 5 | (((uint16_t)rgb.b) >> 3);
-        palette[i].rgb565 = BYTE_SWAP(rgb565);
+        palette[i].rgb565 = __builtin_bswap16(rgb565);
     }
     return true;
 }