From 0dfeaa9dbc9305b7cabd3498f77bc27739e9d842 Mon Sep 17 00:00:00 2001
From: Vito Caputo <vcaputo@pengaru.com>
Date: Sat, 22 Apr 2017 16:01:59 -0700
Subject: julia: utilize context struct for module state

---
 src/modules/julia/julia.c | 130 +++++++++++++++++++++++++++-------------------
 1 file changed, 76 insertions(+), 54 deletions(-)

(limited to 'src/modules/julia')

diff --git a/src/modules/julia/julia.c b/src/modules/julia/julia.c
index 3811d0d..3215902 100644
--- a/src/modules/julia/julia.c
+++ b/src/modules/julia/julia.c
@@ -1,6 +1,7 @@
 #include <stdint.h>
 #include <inttypes.h>
 #include <math.h>
+#include <stdlib.h>
 
 #include "fb.h"
 #include "rototiller.h"
@@ -11,11 +12,69 @@
 
 /* TODO: explore using C99 complex.h and its types? */
 
-static float	rr;
-static float	realscale;
-static float	imagscale;
-static float	creal;
-static float	cimag;
+typedef struct julia_context_t {
+	float	rr;
+	float	realscale;
+	float	imagscale;
+	float	creal;
+	float	cimag;
+} julia_context_t;
+
+static uint32_t	colors[] = {
+			/* this palette is just something I slapped together, definitely needs improvement. TODO */
+			0x000000,
+			0x000044,
+			0x000088,
+			0x0000aa,
+			0x0000ff,
+			0x0044ff,
+			0x0088ff,
+			0x00aaff,
+			0x00ffff,
+			0x44ffaa,
+			0x88ff88,
+			0xaaff44,
+			0xffff00,
+			0xffaa00,
+			0xff8800,
+			0xff4400,
+			0xff0000,
+			0xaa0000,
+			0x880000,
+			0x440000,
+			0x440044,
+			0x880088,
+			0xaa00aa,
+			0xff00ff,
+			0xff4400,
+			0xff8800,
+			0xffaa00,
+			0xffff00,
+			0xaaff44,
+			0x88ff88,
+			0x44ffaa,
+			0x00ffff,
+			0x00aaff,
+			0x0088ff,
+			0xff4400,
+			0xff00ff,
+			0xaa00aa,
+			0x880088,
+			0x440044,
+		};
+
+
+static void * julia_create_context(void)
+{
+	return calloc(1, sizeof(julia_context_t));
+}
+
+
+static void julia_destroy_context(void *context)
+{
+	free(context);
+
+}
 
 static inline unsigned julia_iter(float real, float imag, float creal, float cimag, unsigned max_iters)
 {
@@ -44,66 +103,26 @@ static inline unsigned julia_iter(float real, float imag, float creal, float cim
 /* Prepare a frame for concurrent drawing of fragment using multiple fragments */
 static void julia_prepare_frame(void *context, unsigned n_cpus, fb_fragment_t *fragment, rototiller_frame_t *res_frame)
 {
+	julia_context_t	*ctxt = context;
+
 	res_frame->n_fragments = n_cpus;
 	fb_fragment_divide(fragment, n_cpus, res_frame->fragments);
 
-	rr += .01;
+	ctxt->rr += .01;
 			/* Rather than just sweeping creal,cimag from -2.0-+2.0, I try to keep things confined
 			 * to an interesting (visually) range.  TODO: could certainly use refinement.
 			 */
-	realscale = 0.01f * cosf(rr) + 0.01f;
-	imagscale = 0.01f * sinf(rr * 3.0f) + 0.01f;
-	creal = (1.01f + (realscale * cosf(1.5f*M_PI+rr) + realscale)) * cosf(rr * .3f);
-	cimag = (1.01f + (imagscale * sinf(rr * 3.0f) + imagscale)) * sinf(rr);
+	ctxt->realscale = 0.01f * cosf(ctxt->rr) + 0.01f;
+	ctxt->imagscale = 0.01f * sinf(ctxt->rr * 3.0f) + 0.01f;
+	ctxt->creal = (1.01f + (ctxt->realscale * cosf(1.5f * M_PI + ctxt->rr) + ctxt->realscale)) * cosf(ctxt->rr * .3f);
+	ctxt->cimag = (1.01f + (ctxt->imagscale * sinf(ctxt->rr * 3.0f) + ctxt->imagscale)) * sinf(ctxt->rr);
 }
 
 
 /* Draw a morphing Julia set */
 static void julia_render_fragment(void *context, fb_fragment_t *fragment)
 {
-	static uint32_t	colors[] = {
-				/* this palette is just something I slapped together, definitely needs improvement. TODO */
-				0x000000,
-				0x000044,
-				0x000088,
-				0x0000aa,
-				0x0000ff,
-				0x0044ff,
-				0x0088ff,
-				0x00aaff,
-				0x00ffff,
-				0x44ffaa,
-				0x88ff88,
-				0xaaff44,
-				0xffff00,
-				0xffaa00,
-				0xff8800,
-				0xff4400,
-				0xff0000,
-				0xaa0000,
-				0x880000,
-				0x440000,
-				0x440044,
-				0x880088,
-				0xaa00aa,
-				0xff00ff,
-				0xff4400,
-				0xff8800,
-				0xffaa00,
-				0xffff00,
-				0xaaff44,
-				0x88ff88,
-				0x44ffaa,
-				0x00ffff,
-				0x00aaff,
-				0x0088ff,
-				0xff4400,
-				0xff00ff,
-				0xaa00aa,
-				0x880088,
-				0x440044,
-			};
-
+	julia_context_t	*ctxt = context;
 	unsigned	x, y;
 	unsigned	stride = fragment->stride / 4, width = fragment->width, height = fragment->height;
 	uint32_t	*buf = fragment->buf;
@@ -114,14 +133,17 @@ static void julia_render_fragment(void *context, fb_fragment_t *fragment)
 	/* Complex plane confined to {-1.8 - 1.8} on both axis (slightly zoomed), no dynamic zooming is performed. */
 	for (imag = 1.8 + -(imagstep * (float)fragment->y), y = fragment->y; y < fragment->y + height; y++, imag += -imagstep) {
 		for (real = -1.8 + realstep * (float)fragment->x, x = fragment->x; x < fragment->x + width; x++, buf++, real += realstep) {
-			*buf = colors[julia_iter(real, imag, creal, cimag, sizeof(colors) / sizeof(*colors))];
+			*buf = colors[julia_iter(real, imag, ctxt->creal, ctxt->cimag, sizeof(colors) / sizeof(*colors))];
 		}
 
 		buf += stride;
 	}
 }
 
+
 rototiller_module_t	julia_module = {
+	.create_context = julia_create_context,
+	.destroy_context = julia_destroy_context,
 	.prepare_frame = julia_prepare_frame,
 	.render_fragment = julia_render_fragment,
 	.name = "julia",
-- 
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