C API: add radial, sweep, and two-point conical gradient shaders

tests/CTest.cpp

Index: tests/CTest.cpp
diff --git a/tests/CTest.cpp b/tests/CTest.cpp
index 413f629ee3f2f4bfc4f1f24a2b01e4a5817719c3..194b8f04f2366fb06e183aee975d90e8f42ddd32 100644
--- a/tests/CTest.cpp
+++ b/tests/CTest.cpp
@@ -8,9 +8,51 @@
 #include "sk_canvas.h"
 #include "sk_paint.h"
 #include "sk_surface.h"
+#include "sk_shader.h"
 
 #include "Test.h"
 
+
+static void shader_test(skiatest::Reporter* reporter) {
+    sk_imageinfo_t info =
+        {64, 64, sk_colortype_get_default_8888(), PREMUL_SK_ALPHATYPE};
+    sk_surface_t* surface  = sk_surface_new_raster(&info, NULL);
+    sk_canvas_t* canvas = sk_surface_get_canvas(surface);
+    sk_paint_t* paint = sk_paint_new();
+
+    sk_shader_tilemode_t tilemode = CLAMP_SK_SHADER_TILEMODE;
+    sk_point_t point = {0.0f, 0.0f};
+    sk_point_t point2 = {30.0f, 40.0f};
+    sk_color_t colors[] = {
+        (sk_color_t)sk_color_set_argb(0xFF, 0x00, 0x00, 0xFF),
+        (sk_color_t)sk_color_set_argb(0xFF, 0x00, 0xFF, 0x00)
+    };
+    sk_shader_t* shader;
+
+    shader = sk_shader_new_radial_gradient(
+            &point, 1.0f, colors, NULL, 2, tilemode, NULL);
+    REPORTER_ASSERT(reporter, shader != NULL);
+    sk_paint_set_shader(paint, shader);
+    sk_shader_unref(shader);
+    sk_canvas_draw_paint(canvas, paint);
+
+    shader = sk_shader_new_sweep_gradient(&point, colors, NULL, 2, NULL);
+    REPORTER_ASSERT(reporter, shader != NULL);
+    sk_paint_set_shader(paint, shader);
+    sk_shader_unref(shader);
+    sk_canvas_draw_paint(canvas, paint);
+
+    shader = sk_shader_new_two_point_conical_gradient(
+            &point, 10.0f,  &point2, 50.0f, colors, NULL, 2, tilemode, NULL);
+    REPORTER_ASSERT(reporter, shader != NULL);
+    sk_paint_set_shader(paint, shader);
+    sk_shader_unref(shader);
+    sk_canvas_draw_paint(canvas, paint);
+
+    sk_paint_delete(paint);
+    sk_surface_unref(surface);
+}
+
 static void test_c(skiatest::Reporter* reporter) {
     sk_colortype_t ct = sk_colortype_get_default_8888();
 
@@ -38,4 +80,5 @@ static void test_c(skiatest::Reporter* reporter) {
 
 DEF_TEST(C_API, reporter) {
     test_c(reporter);
+    shader_test(reporter);
 }