PicoVector: Big refactor, ppp primitives.

* Remove Polygon types in favour of primitives .circle, .rectangle etc
* Add a new Transform type for building up transformation matrices
* Add support to set/clear transform on drawing

libraries/pico_vector/pico_vector.cpp

@@ -1,8 +1,10 @@
 #define PP_IMPLEMENTATION
 #define AF_IMPLEMENTATION
+#define PPP_IMPLEMENTATION
 #include "pico_vector.hpp"
 #include <vector>
 
+
 namespace pimoroni {
   PicoGraphics *PicoVector::graphics = nullptr;
 

libraries/pico_vector/pico_vector.hpp

@@ -17,6 +17,7 @@
 #define AF_DEBUG(...)          af_debug(__VA_ARGS__)
 
 #include "pretty-poly.h"
+#include "pretty-poly-primitives.h"
 #include "alright-fonts.h"
 #include "pico_graphics.hpp"
 
@@ -29,10 +30,10 @@ namespace pimoroni {
 
     class PicoVector {
         private:
-            static PicoGraphics *graphics;
             af_text_metrics_t text_metrics;
 
         public:
+            static PicoGraphics *graphics;
             PicoVector(PicoGraphics *graphics, void *mem = nullptr) {
                 PicoVector::graphics = graphics;
 

libraries/pico_vector/pretty-poly-primitives.h

@@ -0,0 +1,181 @@
+/*
+
+  Pretty Poly 🦜 - super-sampling polygon renderer for low resource platforms.
+
+  Jonathan Williamson, August 2022
+  Examples, source, and more: https://github.com/lowfatcode/pretty-poly
+  MIT License https://github.com/lowfatcode/pretty-poly/blob/main/LICENSE
+
+  An easy way to render high quality graphics in embedded applications running
+  on resource constrained microcontrollers such as the Cortex M0 and up.
+
+    - Renders polygons: concave, self-intersecting, multi contour, holes, etc.
+    - C11 header only library: simply copy the header file into your project
+    - Tile based renderer: low memory footprint, cache coherency
+    - Low memory usage: ~4kB of heap memory required
+    - High speed on low resource platforms: optionally no floating point
+    - Antialiasing modes: X1 (none), X4 and X16 super sampling
+    - Bounds clipping: all results clipped to supplied clip rectangle
+    - Pixel format agnostic: renders a "tile" to blend into your framebuffer
+    - Support for hardware interpolators on rp2040 (thanks @MichaelBell!)
+
+  Contributor bwaaaaaarks! 🦜
+
+    @MichaelBell - lots of bug fixes, performance boosts, and suggestions.
+    @gadgetoid - integrating into the PicoVector library and testing.
+
+*/
+
+#ifndef PPP_INCLUDE_H
+#define PPP_INCLUDE_H
+
+#include "pretty-poly.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+typedef struct {
+  PP_COORD_TYPE x, y, w, h;      // coordinates
+  PP_COORD_TYPE s;               // stroke thickness (0 == filled)
+  PP_COORD_TYPE r1, r2, r3, r4;  // corner radii (r1 = top left then clockwise)
+} ppp_rect_def;
+
+typedef struct {
+  PP_COORD_TYPE x, y;            // coordinates
+  PP_COORD_TYPE r;               // radius
+  int e;                         // edge count
+  PP_COORD_TYPE s;               // stroke thickness (0 == filled)
+} ppp_regular_def;
+
+typedef struct {
+  PP_COORD_TYPE x, y;            // coordinates
+  PP_COORD_TYPE r;               // radius
+  PP_COORD_TYPE s;               // stroke thickness (0 == filled)
+} ppp_circle_def;
+
+typedef struct {
+  PP_COORD_TYPE x, y;            // coordinates
+  PP_COORD_TYPE r;               // radius
+  PP_COORD_TYPE s;               // stroke thickness (0 == filled)
+  PP_COORD_TYPE f, t;            // angle from and to
+} ppp_arc_def;
+
+pp_poly_t* ppp_rect(ppp_rect_def d);
+pp_poly_t* ppp_regular(ppp_regular_def d);
+pp_poly_t* ppp_circle(ppp_circle_def d);
+pp_poly_t* ppp_arc(ppp_arc_def d);
+
+#ifdef __cplusplus
+}
+#endif
+
+#ifdef PPP_IMPLEMENTATION
+
+void _pp_round_rect_corner_points(pp_path_t *path, PP_COORD_TYPE cx, PP_COORD_TYPE cy, PP_COORD_TYPE r, int q) {
+  float quality = 5; // higher the number, lower the quality - selected by experiment
+  int steps = ceil(r / quality) + 2; // + 2 to include start and end
+  float delta = -(M_PI / 2) / steps;
+  float theta = (M_PI / 2) * q; // select start theta for this quadrant
+  for(int i = 0; i <= steps; i++) {
+    PP_COORD_TYPE xo = sin(theta) * r, yo = cos(theta) * r;
+    pp_path_add_point(path, (pp_point_t){cx + xo, cy + yo});
+    theta += delta;
+  }
+}
+
+void _ppp_rrect_corner(pp_path_t *path, PP_COORD_TYPE cx, PP_COORD_TYPE cy, PP_COORD_TYPE r, int q) {
+  float quality = 5; // higher the number, lower the quality - selected by experiment
+  int steps = ceil(r / quality) + 2; // + 2 to include start and end
+  float delta = -(M_PI / 2) / steps;
+  float theta = (M_PI / 2) * q; // select start theta for this quadrant
+  for(int i = 0; i <= steps; i++) {
+    PP_COORD_TYPE xo = sin(theta) * r, yo = cos(theta) * r;
+    pp_path_add_point(path, (pp_point_t){cx + xo, cy + yo});
+    theta += delta;
+  }
+}
+
+void _ppp_rrect_path(pp_path_t *path, ppp_rect_def d) {
+  d.r1 == 0 ? pp_path_add_point(path, (pp_point_t){d.x, d.y})             : _ppp_rrect_corner(path, d.x + d.r1, d.y + d.r1, d.r1, 3);
+  d.r2 == 0 ? pp_path_add_point(path, (pp_point_t){d.x + d.w, d.y})       : _ppp_rrect_corner(path, d.x + d.w - d.r2, d.y + d.r2, d.r2, 2);
+  d.r3 == 0 ? pp_path_add_point(path, (pp_point_t){d.x + d.w, d.y + d.h}) : _ppp_rrect_corner(path, d.x + d.w - d.r3, d.y + d.h - d.r3, d.r3, 1);
+  d.r4 == 0 ? pp_path_add_point(path, (pp_point_t){d.x, d.y})             : _ppp_rrect_corner(path, d.x + d.r4, d.y + d.h - d.r4, d.r4, 0);
+}
+
+pp_poly_t* ppp_rect(ppp_rect_def d) {
+  pp_poly_t *poly = pp_poly_new();
+  pp_path_t *path = pp_poly_add_path(poly);
+  if(d.r1 == 0.0f && d.r2 ==  0.0f && d.r3 ==  0.0f && d.r4 == 0.0f) { // non rounded rect
+    pp_point_t points[] = {{d.x, d.y}, {d.x + d.w, d.y}, {d.x + d.w, d.y + d.h}, {d.x, d.y + d.h}};
+    pp_path_add_points(path, points, 4);
+    if(d.s != 0) { // stroked, not filled
+      d.x += d.s; d.y += d.s; d.w -= 2 * d.s; d.h -= 2 * d.s;
+      pp_path_t *inner = pp_poly_add_path(poly);
+        pp_point_t points[] = {{d.x, d.y}, {d.x + d.w, d.y}, {d.x + d.w, d.y + d.h}, {d.x, d.y + d.h}};
+      pp_path_add_points(inner, points, 4);
+    }
+  }else{ // rounded rect
+    _ppp_rrect_path(path, d);
+    if(d.s != 0) { // stroked, not filled
+      d.x += d.s; d.y += d.s; d.w -= 2 * d.s; d.h -= 2 * d.s;
+      d.r1 = _pp_max(0, d.r1 - d.s);
+      d.r2 = _pp_max(0, d.r2 - d.s);
+      d.r3 = _pp_max(0, d.r3 - d.s);
+      d.r4 = _pp_max(0, d.r4 - d.s);
+      pp_path_t *inner = pp_poly_add_path(poly);
+      _ppp_rrect_path(inner, d);
+    }
+  }
+  return poly;
+}
+
+pp_poly_t* ppp_regular(ppp_regular_def d) {
+  pp_poly_t *poly = pp_poly_new();
+  pp_path_t *path = pp_poly_add_path(poly);
+  pp_path_t *inner = d.s != 0.0f ? pp_poly_add_path(poly) : NULL;
+  for(int i = 0; i < d.e; i++) {
+    float theta = ((M_PI * 2.0f) / (float)d.e) * (float)i;
+    pp_path_add_point(path, (pp_point_t){sin(theta) * d.r + d.x, cos(theta) * d.r + d.y});
+    if(inner) {
+      pp_path_add_point(inner, (pp_point_t){sin(theta) * (d.r - d.s) + d.x, cos(theta) * (d.r - d.s) + d.y});
+    }
+  }
+  return poly;
+}
+
+pp_poly_t* ppp_circle(ppp_circle_def d) {
+  int e = _pp_max(8, d.r); // edge count
+  ppp_regular_def r = {d.x, d.y, d.r, e, d.s};
+  return ppp_regular(r);
+}
+
+pp_poly_t* ppp_arc(ppp_arc_def d) {
+  pp_poly_t *poly = pp_poly_new();
+  pp_path_t *path = pp_poly_add_path(poly);
+  pp_path_t *inner = (pp_path_t *)(d.s == 0.0f ? NULL : calloc(1, sizeof(pp_path_t)));
+
+  // no thickness, so add centre point to make pie shape
+  if(!inner) pp_path_add_point(path, (pp_point_t){d.x, d.y});
+
+  d.f = d.f * (M_PI / 180.0f); d.t = d.t * (M_PI / 180.0f); // to radians
+  int s = _pp_max(8, d.r); float astep = (d.t - d.f) / s; float a = d.f;
+  for(int i = 0; i <= s; i++) {
+    pp_path_add_point(path, (pp_point_t){sin(a) * d.r + d.x, cos(a) * d.r + d.y});
+    if(inner) {
+      pp_path_add_point(inner, (pp_point_t){sin(d.t - (a - d.f)) * (d.r - d.s) + d.x, cos(d.t - (a - d.f)) * (d.r - d.s) + d.y});
+    }
+    a += astep;
+  }
+
+  if(inner) { // append the inner path
+    pp_path_add_points(path, inner->points, inner->count);
+    free(inner->points); free(inner);
+  }
+
+  return poly;
+}
+
+#endif // PPP_IMPLEMENTATION
+
+#endif // PPP_INCLUDE_H