From bce8d1b1e019e12402feff28ee2abeb1bbef63f4 Mon Sep 17 00:00:00 2001
From: cxp2249 <moritz.pirk@tuhh.de>
Date: Sun, 21 Jan 2018 17:24:19 +0100
Subject: added multithreading

---
 src/render.c | 92 +++++++++++++++++++++++++++++++++++++++++++++++-------------
 1 file changed, 73 insertions(+), 19 deletions(-)

diff --git a/src/render.c b/src/render.c
index e06c967..528d775 100644
--- a/src/render.c
+++ b/src/render.c
@@ -6,6 +6,8 @@
  */
 
 #include "render.h"
+#define HAVE_STRUCT_TIMESPEC
+#include <pthread.h>
 
 void render_init(Config *config, u32 (*sfunc) (double, double, u32))
 {
@@ -39,34 +41,86 @@ void on_draw(GtkWidget *widget, cairo_t *cr, gpointer data)
 	cairo_paint(cr);
 }
 
+struct arg_thread {
+	cairo_surface_t *result;
+	unsigned short threadCount;
+	unsigned short threadNumber;
+	unsigned char *current_row;
+};
+
+void *imageCalcThread(void *arguments)
+{
+
+
+	struct arg_thread *args = arguments;
+	cairo_surface_t *result = args->result;
+	unsigned int threadCount = args->threadCount;
+	unsigned int threadNumber = args->threadNumber;
+	unsigned char *current_row = args->current_row;
+
+
+
+	int stride;
+	double x_math, y_math;
+	u32 iterations;
+
+	printf("thread calculating %s",result);
+	current_row = cairo_image_surface_get_data(result);
+	stride = cairo_image_surface_get_stride(result);
+
+
+	//Calculating start and endpoint for current thread to calculate
+	int startingPoint = (_config->height/threadCount)*(threadNumber);
+	int endPoint = ((_config->height/threadCount)*(threadNumber + 1)) - 1;
+
+
+	for (int y = startingPoint; y < endPoint && y < _config->height; y++) {
+		u32 *row = (void *) current_row;
+		for (int x = 0; x < _config->width; x++) {
+			x_math = /*x_MIN*/-2.0 + ((double) x * (/*x_MAX*/1.0 - /*x_MIN*/-2.0)) / _config->width;
+			y_math = /*y_MIN*/-1.0 + ((double) (_config->height - y) * (/*y_MAX*/1.0 - /*y_MIN*/-1.0)) / _config->height;
+			iterations = _sfunc(x_math, y_math, _config->iterations);
+			row[x] = (((1<<24)-1)*iterations)/_config->iterations;
+//            if (iterations > 1<<8)
+//            	printf("schon gruen\n");
+		}
+
+		current_row += stride;
+	}
+
+}
+
 cairo_surface_t *render_surface()
 {
     cairo_surface_t *result;
+    unsigned short threadCount = 4;
     unsigned char *current_row;
-    int stride;
-    double x_math, y_math;
-    u32 iterations;
 
-    result = cairo_image_surface_create(CAIRO_FORMAT_RGB24, _config->width, _config->height);
-    if (cairo_surface_status(result) != CAIRO_STATUS_SUCCESS)
-        return result;
+	result = cairo_image_surface_create(CAIRO_FORMAT_RGB24, _config->width, _config->height);
+		if (cairo_surface_status(result) != CAIRO_STATUS_SUCCESS)
+			return result;
 
     cairo_surface_flush(result);
-    current_row = cairo_image_surface_get_data(result);
-    stride = cairo_image_surface_get_stride(result);
-    for (int y = 0; y < _config->height; y++) {
-        u32 *row = (void *) current_row;
-        for (int x = 0; x < _config->width; x++) {
-        	x_math = /*x_MIN*/-2.0 + ((double) x * (/*x_MAX*/1.0 - /*x_MIN*/-2.0)) / _config->width;
-        	y_math = /*y_MIN*/-1.0 + ((double) (_config->height - y) * (/*y_MAX*/1.0 - /*y_MIN*/-1.0)) / _config->height;
-        	iterations = _sfunc(x_math, y_math, _config->iterations);
-            row[x] = (((1<<24)-1)*iterations)/_config->iterations;
-//            if (iterations > 1<<8)
-//            	printf("schon gruen\n");
-        }
 
-        current_row += stride;
+
+
+    //initialize thread related values and put them into a struct, as just one parameter is passed
+    struct arg_thread args;
+    args.result = result;
+    args.threadCount = threadCount;
+    args.current_row = current_row;
+
+    pthread_t tid;
+
+    //Create threads up to the number specified in threadCount
+    for (int i = 0; i < threadCount; i++){
+    	   args.threadNumber = i;
+           pthread_create(&tid, NULL, imageCalcThread, (void *)&args);
     }
+
+    //Wait for threads to finish and continue with the program
+    pthread_join(tid,NULL);
+
     cairo_surface_mark_dirty(result);
     return result;
 }
-- 
cgit v1.2.1