Skia Compute core files
Bug: skia:
Change-Id: I4bba49cf20eff013e581800a3f114c85acd8498c
Reviewed-on: https://skia-review.googlesource.com/135782
Reviewed-by: Mike Klein <mtklein@google.com>
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
diff --git a/src/compute/skc/path_builder.c b/src/compute/skc/path_builder.c
new file mode 100644
index 0000000..15372de
--- /dev/null
+++ b/src/compute/skc/path_builder.c
@@ -0,0 +1,272 @@
+/*
+ * Copyright 2017 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can
+ * be found in the LICENSE file.
+ *
+ */
+
+//
+//
+//
+
+#include "path_builder.h"
+#include "context.h"
+
+//
+//
+//
+
+skc_err
+skc_path_builder_retain(skc_path_builder_t path_builder)
+{
+ ++path_builder->refcount;
+
+ return SKC_ERR_SUCCESS;
+}
+
+skc_err
+skc_path_builder_release(skc_path_builder_t path_builder)
+{
+ SKC_ASSERT_STATE_ASSERT(SKC_PATH_BUILDER_STATE_READY,path_builder);
+
+ path_builder->release(path_builder->impl);
+
+ return SKC_ERR_SUCCESS;
+}
+
+//
+// PATH BODY
+//
+
+skc_err
+skc_path_begin(skc_path_builder_t path_builder)
+{
+ SKC_ASSERT_STATE_TRANSITION(SKC_PATH_BUILDER_STATE_READY,
+ SKC_PATH_BUILDER_STATE_BUILDING,
+ path_builder);
+
+ // init path builder counters
+ path_builder->line .rem = 0;
+ path_builder->quad .rem = 0;
+ path_builder->cubic.rem = 0;
+
+ // begin the path
+ path_builder->begin(path_builder->impl);
+
+ return SKC_ERR_SUCCESS;
+}
+
+skc_err
+skc_path_end(skc_path_builder_t path_builder, skc_path_t * path)
+{
+ SKC_ASSERT_STATE_TRANSITION(SKC_PATH_BUILDER_STATE_BUILDING,
+ SKC_PATH_BUILDER_STATE_READY,
+ path_builder);
+
+ // update path header with proper counts
+ path_builder->end(path_builder->impl,path);
+
+ return SKC_ERR_SUCCESS;
+}
+
+//
+// PATH SEGMENT OPS
+//
+
+static
+void
+skc_path_move_to_1(skc_path_builder_t path_builder,
+ float x0, float y0)
+{
+ path_builder->curr[0].x = x0;
+ path_builder->curr[0].y = y0;
+ path_builder->curr[1].x = x0;
+ path_builder->curr[1].y = y0;
+}
+
+static
+void
+skc_path_move_to_2(skc_path_builder_t path_builder,
+ float x0, float y0,
+ float x1, float y1)
+{
+ path_builder->curr[0].x = x0;
+ path_builder->curr[0].y = y0;
+ path_builder->curr[1].x = x1;
+ path_builder->curr[1].y = y1;
+}
+
+skc_err
+skc_path_move_to(skc_path_builder_t path_builder,
+ float x0, float y0)
+{
+ skc_path_move_to_1(path_builder,x0,y0);
+
+ return SKC_ERR_SUCCESS;
+}
+
+skc_err
+skc_path_close(skc_path_builder_t path_builder)
+{
+ //
+ // FIXME -- CLARIFY WHY SUBTLE AUTO-CLOSE BEHAVIORS _DON'T BELONG_
+ // IN THE SKIA COMPUTE LAYER
+ //
+ // OR, BETTER YET, GET RID OF THIS FUNC ENTIRELY
+ //
+ return SKC_ERR_NOT_IMPLEMENTED;
+}
+
+skc_err
+skc_path_line_to(skc_path_builder_t path_builder,
+ float x1, float y1)
+{
+ if (path_builder->line.rem == 0) {
+ path_builder->new_line(path_builder->impl);
+ }
+
+ --path_builder->line.rem;
+
+ *path_builder->line.coords[0]++ = path_builder->curr[0].x;
+ *path_builder->line.coords[1]++ = path_builder->curr[0].y;
+ *path_builder->line.coords[2]++ = x1;
+ *path_builder->line.coords[3]++ = y1;
+
+ skc_path_move_to_1(path_builder,x1,y1);
+
+ return SKC_ERR_SUCCESS;
+}
+
+skc_err
+skc_path_quad_to(skc_path_builder_t path_builder,
+ float x1, float y1,
+ float x2, float y2)
+{
+ if (path_builder->quad.rem == 0) {
+ path_builder->new_quad(path_builder->impl);
+ }
+
+ --path_builder->quad.rem;
+
+ *path_builder->quad.coords[0]++ = path_builder->curr[0].x;
+ *path_builder->quad.coords[1]++ = path_builder->curr[0].y;
+ *path_builder->quad.coords[2]++ = x1;
+ *path_builder->quad.coords[3]++ = y1;
+ *path_builder->quad.coords[4]++ = x2;
+ *path_builder->quad.coords[5]++ = y2;
+
+ skc_path_move_to_2(path_builder,x2,y2,x1,y1);
+
+ return SKC_ERR_SUCCESS;
+}
+
+skc_err
+skc_path_quad_smooth_to(skc_path_builder_t path_builder,
+ float x2, float y2)
+{
+ float const x1 = path_builder->curr[0].x * 2.0f - path_builder->curr[1].x;
+ float const y1 = path_builder->curr[0].y * 2.0f - path_builder->curr[1].y;
+
+ return skc_path_quad_to(path_builder,x1,y1,x2,y2);
+}
+
+skc_err
+skc_path_cubic_to(skc_path_builder_t path_builder,
+ float x1, float y1,
+ float x2, float y2,
+ float x3, float y3)
+{
+ if (path_builder->cubic.rem == 0) {
+ path_builder->new_cubic(path_builder->impl);
+ }
+
+ --path_builder->cubic.rem;
+
+ *path_builder->cubic.coords[0]++ = path_builder->curr[0].x;
+ *path_builder->cubic.coords[1]++ = path_builder->curr[0].y;
+ *path_builder->cubic.coords[2]++ = x1;
+ *path_builder->cubic.coords[3]++ = y1;
+ *path_builder->cubic.coords[4]++ = x2;
+ *path_builder->cubic.coords[5]++ = y2;
+ *path_builder->cubic.coords[6]++ = x3;
+ *path_builder->cubic.coords[7]++ = y3;
+
+ skc_path_move_to_2(path_builder,x3,y3,x2,y2);
+
+ return SKC_ERR_SUCCESS;
+}
+
+skc_err
+skc_path_cubic_smooth_to(skc_path_builder_t path_builder,
+ float x2, float y2,
+ float x3, float y3)
+{
+ float const x1 = path_builder->curr[0].x * 2.0f - path_builder->curr[1].x;
+ float const y1 = path_builder->curr[0].y * 2.0f - path_builder->curr[1].y;
+
+ return skc_path_cubic_to(path_builder,x1,y1,x2,y2,x3,y3);
+}
+
+//
+// FIXME -- add rational quad and cubic support and move primitives
+// like ellipse into an adapter. They do *not* belong in the core API.
+//
+
+skc_err
+skc_path_ellipse(skc_path_builder_t path_builder,
+ float cx, float cy,
+ float rx, float ry)
+{
+ //
+ // FIXME -- we can implement this with rationals later...
+ //
+
+ //
+ // Approximate a circle with 4 cubics:
+ //
+ // http://en.wikipedia.org/wiki/B%C3%A9zier_spline#Approximating_circular_arcs
+ //
+ skc_path_move_to_1(path_builder, cx, cy + ry);
+
+#define KAPPA_FLOAT 0.55228474983079339840f // moar digits!
+
+ float const kx = rx * KAPPA_FLOAT;
+ float const ky = ry * KAPPA_FLOAT;
+
+ skc_err err;
+
+ err = skc_path_cubic_to(path_builder,
+ cx + kx, cy + ry,
+ cx + rx, cy + ky,
+ cx + rx, cy);
+
+ if (err)
+ return err;
+
+ err = skc_path_cubic_to(path_builder,
+ cx + rx, cy - ky,
+ cx + kx, cy - ry,
+ cx, cy - ry);
+
+ if (err)
+ return err;
+
+ err = skc_path_cubic_to(path_builder,
+ cx - kx, cy - ry,
+ cx - rx, cy - ky,
+ cx - rx, cy);
+
+ if (err)
+ return err;
+
+ err = skc_path_cubic_to(path_builder,
+ cx - rx, cy + ky,
+ cx - kx, cy + ry,
+ cx, cy + ry);
+ return err;
+}
+
+//
+//
+//