From fd421e32780cad46782c16cd4e15947f295a08c7 Mon Sep 17 00:00:00 2001
From: Tom Smeding <tom.smeding@gmail.com>
Date: Fri, 27 Mar 2020 22:47:57 +0100
Subject: Initial, untested version of controller and worker

Worker has been tested to a marginal extent, but the controller is
litereally untested.
---
 examples/mandel/mandel.c | 57 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 examples/mandel/mandel.c

(limited to 'examples/mandel/mandel.c')

diff --git a/examples/mandel/mandel.c b/examples/mandel/mandel.c
new file mode 100644
index 0000000..f7517ba
--- /dev/null
+++ b/examples/mandel/mandel.c
@@ -0,0 +1,57 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+
+struct input {
+	double ltx, lty;
+	double rbx, rby;
+	size_t width, height;
+	size_t maxiter;
+};
+
+int worker_init(int version) {
+	fprintf(stderr, "mandel: init(%d)\n", version);
+	return version == 1 ? 0 : 1;
+}
+
+int worker_run_job(size_t inputsize, const void *input_, size_t *outputsize, void **outputp) {
+	if (inputsize != sizeof(struct input)) {
+		fprintf(stderr, "mandel: Input has invalid size %zu (expected %zu)\n", inputsize, sizeof(struct input));
+		return -1;
+	}
+
+	fprintf(stderr, "mandel: run_job()\n");
+
+	const struct input *const input = input_;
+
+	*outputsize = 4 * input->width * input->height;
+	uint32_t *const output = *outputp = malloc(*outputsize);
+
+#pragma omp parallel for
+	for (size_t yi = 0; yi < input->height; yi++) {
+		for (size_t xi = 0; xi < input->width; xi++) {
+			const double y = (input->rby - input->lty) / (input->height - 1) * yi;
+			const double x = (input->rbx - input->ltx) / (input->width - 1) * xi;
+
+			double a = x, b = y, a2 = a * a, b2 = b * b;
+			size_t n;
+			for (n = 0; n < input->maxiter && a2 + b2 < 4; n++) {
+				b = 2 * a * b + y;
+				a = a2 - b2 + x;
+				a2 = a * a; b2 = b * b;
+			}
+
+			output[input->width * yi + xi] = n;
+		}
+	}
+
+	fprintf(stderr, "mandel: run_job() finished\n");
+
+	return 0;
+}
+
+void worker_free_outdata(size_t size, void *output) {
+	(void)size;
+	fprintf(stderr, "mandel: free_outdata()\n");
+	free(output);
+}
-- 
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