blend

4 files changed, 57 insertions, 17 deletions

diff --git a/main.c b/main.c
index 8c5b29e..53e2c30 100644
--- a/main.c
+++ b/main.c
@@ -7,12 +7,21 @@ main(void)
 {
 	mysrand(time(NULL));
 
-	KldImage *img = kldImage_load("samples/cloud.jpg");
-	kldImage_vflip(img);
-	kldImage_bit3(img);
-	kldImage_resize(img, 1024, 512, 0);
-	kldImage_resizetiled(img, 2048, 2048);
-	kldImage_writePAM(img, stdout);
-	kldImage_free(img);
+	KldImage *cloud = kldImage_load("samples/cloud.jpg");
+	KldImage *sky = kldImage_load("samples/sky.jpg");
+
+	kldImage_resize(cloud, sky->width, sky->height, 0);
+
+	kldImage_vflip(cloud);
+	kldImage_chaos3(cloud);
+
+	kldImage_invert(sky);
+	kldImage_chaos3(sky);
+
+	kldImage_blend(cloud, sky, 0.5f);
+	kldImage_writePAM(cloud, stdout);
+
+	kldImage_free(sky);
+	kldImage_free(cloud);
 	return 0;
 }
diff --git a/samples/sky.jpg b/samples/sky.jpg
new file mode 100644
index 0000000..fe10b5a
--- /dev/null
+++ b/samples/sky.jpg
diff --git a/src/image.c b/src/image.c
index 6fac9b1..46daa23 100644
--- a/src/image.c
+++ b/src/image.c
@@ -171,7 +171,7 @@ kldImage_resize(KldImage *img, size_t w, size_t h, KldColor bg)
 		return -1;
 	}
 	kldImage_clear(new_img, bg);
-	kldImage_copy(new_img, img, 0, 0);
+	kldImage_copy(new_img, img, 0, 0, 0, 0);
 
 	/* move new_img to img */
 	free(img->data);
@@ -195,7 +195,7 @@ kldImage_resizetiled(KldImage *img, size_t w, size_t h)
 		log_error("kldImage_alloc failed");
 		return -1;
 	}
-	kldImage_copytiled(new_img, img, 0, 0);
+	kldImage_copytiled(new_img, img, 0, 0, 0, 0);
 
 	/* move new_img to img */
 	free(img->data);
@@ -255,7 +255,7 @@ kldImage_clear(KldImage *img, KldColor color)
 }
 
 void
-kldImage_copy(KldImage *dest, KldImage *src, int x, int y)
+kldImage_copy(KldImage *dest, KldImage *src, int x, int y, int w, int h)
 {
 	NULL_SAFETY_EX_NO_RV(dest);
 	NULL_SAFETY_EX_NO_RV(src);
@@ -269,7 +269,7 @@ kldImage_copy(KldImage *dest, KldImage *src, int x, int y)
 		iy = 0;
 		dy = y;
 	}
-	while (iy < src->height && dy < dest->height) {
+	while (iy < src->height && dy < dest->height && --w != 0) {
 		size_t dx;
 		size_t ix;
 		if (x < 0) {
@@ -279,7 +279,7 @@ kldImage_copy(KldImage *dest, KldImage *src, int x, int y)
 			ix = 0;
 			dx = x;
 		}
-		while (ix < src->width && dx < dest->width) {
+		while (ix < src->width && dx < dest->width && --h != 0) {
 			kldImage_set(dest, dx, dy, kldImage_get(src, ix, iy));
 			dx += 1;
 			ix += 1;
@@ -290,17 +290,17 @@ kldImage_copy(KldImage *dest, KldImage *src, int x, int y)
 }
 
 void
-kldImage_copytiled(KldImage *dest, KldImage *src, int x, int y)
+kldImage_copytiled(KldImage *dest, KldImage *src, int x, int y, int w, int h)
 {
 	NULL_SAFETY_EX_NO_RV(dest);
 	NULL_SAFETY_EX_NO_RV(src);
 
 	size_t iy = -y;
 	size_t dy = 0;
-	while (dy < dest->height) {
+	while (dy < dest->height && --h != 0) {
 		size_t ix = -x;
 		size_t dx = 0;
-		while (dx < dest->width) {
+		while (dx < dest->width && --w != 0) {
 			kldImage_set(dest, dx, dy, kldImage_get(src, ix, iy));
 			dx += 1;
 			ix += 1;
@@ -443,3 +443,31 @@ kldImage_mask(KldImage *img, KldColor mask)
 		);
 	}
 }
+
+int
+kldImage_blend(KldImage *img, KldImage *other, float ratio)
+{
+	NULL_SAFETY(-1);
+	NULL_SAFETY_EX(other, -1);
+
+	if (img->width != other->width || img->height != other->height) {
+		log_error("img (%lu x %lu) and other (%lu x %lu) "
+		          "dims don't match",
+		          img->width, img->height, other->width, other->height);
+		return -1;
+	}
+
+	const float iratio = 1.0f - ratio;
+	for (size_t i = 0; i < img->size; i++) {
+		const KldColor c0 = img->data[i];
+		const KldColor c1 = other->data[i];
+		img->data[i] = KLD_COLOR(
+		    (int)(KLD_COLOR_R(c0) * ratio + KLD_COLOR_R(c1) * iratio),
+		    (int)(KLD_COLOR_G(c0) * ratio + KLD_COLOR_G(c1) * iratio),
+		    (int)(KLD_COLOR_B(c0) * ratio + KLD_COLOR_B(c1) * iratio),
+		    (int)(KLD_COLOR_A(c0) * ratio + KLD_COLOR_A(c1) * iratio)
+		);
+	}
+
+	return 0;
+}
diff --git a/src/image.h b/src/image.h
index 82e2090..afaaa44 100644
--- a/src/image.h
+++ b/src/image.h
@@ -29,9 +29,9 @@ int kldImage_writePAM(KldImage *img, FILE *fp);
 
 void kldImage_clear(KldImage *img, KldColor color);
 
-void kldImage_copy(KldImage *dest, KldImage *src, int x, int y);
+void kldImage_copy(KldImage *dest, KldImage *src, int x, int y, int w, int h);
 
-void kldImage_copytiled(KldImage *dest, KldImage *src, int x, int y);
+void kldImage_copytiled(KldImage *dest, KldImage *src, int x, int y, int w, int h);
 
 /* hflip should be faster than vflip */
 void kldImage_hflip(KldImage *img);
@@ -52,3 +52,6 @@ void kldImage_chaos3(KldImage *img);
 void kldImage_bit3(KldImage *img);
 
 void kldImage_mask(KldImage *img, KldColor mask);
+
+/* return -1 if sizes are not equal */
+int kldImage_blend(KldImage *img, KldImage *other, float ratio);