Quantum Painter (#10174)

* Install dependencies before executing unit tests.

* Split out UTF-8 decoder.

* Fixup python formatting rules.

* Add documentation for QGF/QFF and the RLE format used.

* Add CLI commands for converting images and fonts.

* Add stub rules.mk for QP.

* Add stream type.

* Add base driver and comms interfaces.

* Add support for SPI, SPI+D/C comms drivers.

* Include <qp.h> when enabled.

* Add base support for SPI+D/C+RST panels, as well as concrete implementation of ST7789.

* Add support for GC9A01.

* Add support for ILI9341.

* Add support for ILI9163.

* Add support for SSD1351.

* Implement qp_setpixel, including pixdata buffer management.

* Implement qp_line.

* Implement qp_rect.

* Implement qp_circle.

* Implement qp_ellipse.

* Implement palette interpolation.

* Allow for streams to work with either flash or RAM.

* Image loading.

* Font loading.

* QGF palette loading.

* Progressive decoder of pixel data supporting Raw+RLE, 1-,2-,4-,8-bpp monochrome and palette-based images.

* Image drawing.

* Animations.

* Font rendering.

* Check against 256 colours, dump out the loaded palette if debugging enabled.

* Fix build.

* AVR is not the intended audience.

* `qmk format-c`

* Generation fix.

* First batch of docs.

* More docs and examples.

* Review comments.

* Public API documentation.

1 files changed, 172 insertions, 0 deletions

diff --git a/quantum/painter/qp_draw_circle.c b/quantum/painter/qp_draw_circle.c
new file mode 100644
index 0000000000..edaae35835
--- /dev/null
+++ b/quantum/painter/qp_draw_circle.c
@@ -0,0 +1,172 @@
+// Copyright 2021 Paul Cotter (@gr1mr3aver)
+// Copyright 2021 Nick Brassel (@tzarc)
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "qp.h"
+#include "qp_internal.h"
+#include "qp_comms.h"
+#include "qp_draw.h"
+
+// Utilize 8-way symmetry to draw circles
+static bool qp_circle_helper_impl(painter_device_t device, uint16_t centerx, uint16_t centery, uint16_t offsetx, uint16_t offsety, bool filled) {
+    /*
+    Circles have the property of 8-way symmetry, so eight pixels can be drawn
+    for each computed [offsetx,offsety] given the center coordinates
+    represented by [centerx,centery].
+
+    For filled circles, we can draw horizontal lines between each pair of
+    pixels with the same final value of y.
+
+    Two special cases exist and have been optimized:
+    1) offsetx == offsety (the final point), makes half the coordinates
+    equivalent, so we can omit them (and the corresponding fill lines)
+    2) offsetx == 0 (the starting point) means that some horizontal lines
+    would be a single pixel in length, so we write individual pixels instead.
+    This also makes half the symmetrical points identical to their twins,
+    so we only need four points or two points and one line
+    */
+
+    int16_t xpx = ((int16_t)centerx) + ((int16_t)offsetx);
+    int16_t xmx = ((int16_t)centerx) - ((int16_t)offsetx);
+    int16_t xpy = ((int16_t)centerx) + ((int16_t)offsety);
+    int16_t xmy = ((int16_t)centerx) - ((int16_t)offsety);
+    int16_t ypx = ((int16_t)centery) + ((int16_t)offsetx);
+    int16_t ymx = ((int16_t)centery) - ((int16_t)offsetx);
+    int16_t ypy = ((int16_t)centery) + ((int16_t)offsety);
+    int16_t ymy = ((int16_t)centery) - ((int16_t)offsety);
+
+    if (offsetx == 0) {
+        if (!qp_internal_setpixel_impl(device, centerx, ypy)) {
+            return false;
+        }
+        if (!qp_internal_setpixel_impl(device, centerx, ymy)) {
+            return false;
+        }
+        if (filled) {
+            if (!qp_internal_fillrect_helper_impl(device, xpy, centery, xmy, centery)) {
+                return false;
+            }
+        } else {
+            if (!qp_internal_setpixel_impl(device, xpy, centery)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xmy, centery)) {
+                return false;
+            }
+        }
+    } else if (offsetx == offsety) {
+        if (filled) {
+            if (!qp_internal_fillrect_helper_impl(device, xpy, ypy, xmy, ypy)) {
+                return false;
+            }
+            if (!qp_internal_fillrect_helper_impl(device, xpy, ymy, xmy, ymy)) {
+                return false;
+            }
+        } else {
+            if (!qp_internal_setpixel_impl(device, xpy, ypy)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xmy, ypy)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xpy, ymy)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xmy, ymy)) {
+                return false;
+            }
+        }
+
+    } else {
+        if (filled) {
+            if (!qp_internal_fillrect_helper_impl(device, xpx, ypy, xmx, ypy)) {
+                return false;
+            }
+            if (!qp_internal_fillrect_helper_impl(device, xpx, ymy, xmx, ymy)) {
+                return false;
+            }
+            if (!qp_internal_fillrect_helper_impl(device, xpy, ypx, xmy, ypx)) {
+                return false;
+            }
+            if (!qp_internal_fillrect_helper_impl(device, xpy, ymx, xmy, ymx)) {
+                return false;
+            }
+        } else {
+            if (!qp_internal_setpixel_impl(device, xpx, ypy)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xmx, ypy)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xpx, ymy)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xmx, ymy)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xpy, ypx)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xmy, ypx)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xpy, ymx)) {
+                return false;
+            }
+            if (!qp_internal_setpixel_impl(device, xmy, ymx)) {
+                return false;
+            }
+        }
+    }
+
+    return true;
+}
+
+////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+// Quantum Painter External API: qp_circle
+
+bool qp_circle(painter_device_t device, uint16_t x, uint16_t y, uint16_t radius, uint8_t hue, uint8_t sat, uint8_t val, bool filled) {
+    qp_dprintf("qp_circle: entry\n");
+    struct painter_driver_t *driver = (struct painter_driver_t *)device;
+    if (!driver->validate_ok) {
+        qp_dprintf("qp_circle: fail (validation_ok == false)\n");
+        return false;
+    }
+
+    // plot the initial set of points for x, y and r
+    int16_t xcalc = 0;
+    int16_t ycalc = (int16_t)radius;
+    int16_t err   = ((5 - (radius >> 2)) >> 2);
+
+    qp_internal_fill_pixdata(device, (radius * 2) + 1, hue, sat, val);
+
+    if (!qp_comms_start(device)) {
+        qp_dprintf("qp_circle: fail (could not start comms)\n");
+        return false;
+    }
+
+    bool ret = true;
+    if (!qp_circle_helper_impl(device, x, y, xcalc, ycalc, filled)) {
+        ret = false;
+    }
+
+    if (ret) {
+        while (xcalc < ycalc) {
+            xcalc++;
+            if (err < 0) {
+                err += (xcalc << 1) + 1;
+            } else {
+                ycalc--;
+                err += ((xcalc - ycalc) << 1) + 1;
+            }
+            if (!qp_circle_helper_impl(device, x, y, xcalc, ycalc, filled)) {
+                ret = false;
+                break;
+            }
+        }
+    }
+
+    qp_dprintf("qp_circle: %s\n", ret ? "ok" : "fail");
+    qp_comms_stop(device);
+    return ret;
+}