fix: Replace rotation with spinning

1 files changed, 35 insertions, 28 deletions

diff --git a/graphics.c b/graphics.c
index cd4f561..499bd6c 100644
--- a/graphics.c
+++ b/graphics.c
@@ -126,7 +126,7 @@ typedef struct Animation {
 	AnimationEventNode* events;
 } Animation;
 
-typedef ARGB (*PixelRenderer)(const Animation* anim, u32 currentFrame, ARGB pixel, u32 row, u32 col, void* priv);
+typedef ARGB (*PixelRenderer)(const Animation* anim, u32 currentFrame, ARGB pixel, i32 row, i32 col, void* priv);
 
 struct AnimationEventNode {
 	AnimationEventNode* next;
@@ -205,8 +205,8 @@ Animation_render(Animation* anim) {
 	for (int currFrame = 0; currFrame < anim->frameCount; ++currFrame) {
 
 		if (anim->events != NULL)
-			for (int r = 0; r < anim->frameBuffer.width; ++r)
-			for (int c = 0; c < anim->frameBuffer.height; ++c) {
+			for (i32 r = 0; r < anim->frameBuffer.width; ++r)
+			for (i32 c = 0; c < anim->frameBuffer.height; ++c) {
 				for (AnimationEventNode* aen = anim->events; aen != NULL && aen->startFrame <= currFrame; aen = aen->next) {
 					ARGB* pixel = RGBImage_at(anim->frameBuffer, r, c);
 					ARGB newPixel = aen->renderCallback(anim, currFrame, *pixel, r, c, aen->privateData);
@@ -245,7 +245,7 @@ struct CheckerPattern {
 };
 
 ARGB
-CheckerPattern(const Animation* anim, u32 frameIndex, ARGB pixel, u32 r, u32 c, void* priv) {
+CheckerPattern(const Animation* anim, u32 frameIndex, ARGB pixel, i32 r, i32 c, void* priv) {
 	struct CheckerPattern chp = *(struct CheckerPattern*)priv;
 
 	r /= chp.squareSize;
@@ -268,7 +268,7 @@ struct SquareSettings {
 };
 
 ARGB
-Square(const Animation* anim, u32 frameIndex, ARGB pixel, u32 r, u32 c, void* priv) {
+Square(const Animation* anim, u32 frameIndex, ARGB pixel, i32 r, i32 c, void* priv) {
 	struct SquareSettings* set = (struct SquareSettings*)priv;
 
 	if (0 <= r && r <= set->width && 0 <= c && c <= set->height) {
@@ -285,12 +285,12 @@ struct Image {
 };
 
 ARGB
-Image(const Animation* anim, u32 frameIndex, ARGB pixel, u32 r, u32 c, void* priv) {
+Image(const Animation* anim, u32 frameIndex, ARGB pixel, i32 r, i32 c, void* priv) {
 	struct Image img = *(struct Image*)priv;
 
 	if (img.noRepeat == true &&
-		(img.img.width * img.zoom <= c ||
-		 img.img.height * img.zoom <= r))
+		(c < 0 || img.img.width * img.zoom <= c ||
+		 r < 0 || img.img.height * img.zoom <= r))
 	{
 		return pixel;
 	}
@@ -307,7 +307,7 @@ struct Line {
 };
 
 ARGB
-Line(const Animation* anim, u32 frameIndex, ARGB pixel, u32 r, u32 c, void* priv) {
+Line(const Animation* anim, u32 frameIndex, ARGB pixel, i32 r, i32 c, void* priv) {
 	struct Line l = *(struct Line*)priv;
 
 	if (fabs(l.a * c + l.b * r + l.c) / sqrt(l.a * l.a + l.b * l.b) < l.width) {
@@ -348,19 +348,19 @@ struct MoveLinear {
 	PixelRenderer callback;
 	void* priv;
 
-	u32 startRow;
-	u32 startCol;
+	i32 startRow;
+	i32 startCol;
 	float dRow;
 	float dCol;
 	bool wrapCoordinates;
 };
 
 ARGB
-MoveLinear(const Animation* anim, u32 frameIndex, ARGB pixel, u32 r, u32 c, void* priv) {
+MoveLinear(const Animation* anim, u32 frameIndex, ARGB pixel, i32 r, i32 c, void* priv) {
 	struct MoveLinear ml = *(struct MoveLinear*)priv;
 
-	r = (r - ml.startRow - (u32)(frameIndex * ml.dRow));
-	c = (c - ml.startCol - (u32)(frameIndex * ml.dCol));
+	r = (r - ml.startRow - (i32)(frameIndex * ml.dRow));
+	c = (c - ml.startCol - (i32)(frameIndex * ml.dCol));
 
 	if (ml.wrapCoordinates == true) {
 		r %= anim->width;
@@ -370,24 +370,31 @@ MoveLinear(const Animation* anim, u32 frameIndex, ARGB pixel, u32 r, u32 c, void
 	return ml.callback(anim, frameIndex, pixel, r, c, ml.priv);
 }
 
-struct MoveRotate {
+struct MoveSpin {
 	PixelRenderer callback;
 	void* priv;
 
-	float radius;
 	float theta;
+	i32 centerRow;
+	i32 centerCol;
 };
 
 ARGB
-MoveRotate(const Animation* anim, u32 frameIndex, ARGB pixel, u32 r, u32 c, void* priv) {
-	struct MoveRotate mr = *(struct MoveRotate*)priv;
+MoveSpin(const Animation* anim, u32 frameIndex, ARGB pixel, i32 r, i32 c, void* priv) {
+	struct MoveSpin ms = *(struct MoveSpin*)priv;
 
-	r = (r + (u32)(mr.radius * cos(mr.theta * frameIndex))) % anim->width;
-	c = (c + (u32)(mr.radius * sin(mr.theta * frameIndex))) % anim->height;
+	double radius = sqrt(r * r + c * c);
+	double phi = atan2(c, r);
 
-	return mr.callback(anim, frameIndex, pixel, r, c, mr.priv);
+	phi += ms.theta * frameIndex;
+
+	r = (ms.centerRow + (i32)(radius * cos(phi)));
+	c = (ms.centerCol + (i32)(radius * sin(phi)));
+
+	return ms.callback(anim, frameIndex, pixel, r, c, ms.priv);
 }
 
+
 struct Interpolate {
 	PixelRenderer callback;
 	void* priv;
@@ -401,7 +408,7 @@ struct Interpolate {
 };
 
 ARGB
-Interpolate(const Animation* anim, u32 frameIndex, ARGB pixel, u32 r, u32 c, void* priv) {
+Interpolate(const Animation* anim, u32 frameIndex, ARGB pixel, i32 r, i32 c, void* priv) {
 	struct Interpolate in = *(struct Interpolate*)priv;
 
 	double perc = (double)(frameIndex - in.startFrame) / (in.endFrame - in.startFrame);
@@ -474,20 +481,20 @@ main() {
 	struct SquareSettings s1 = {
 		.width = 20, .height = 20, .color = 0xFFFFFF00,
 	};
-	struct MoveRotate mr1 = {
-		.radius = 20, .theta = 3.14159 / 20,
+	struct MoveSpin ms1 = {
+		.theta = 3.14159 / 15, .centerCol = 10, .centerRow = 10,
 
 		.callback = Square, .priv = &s1,
 	};
 	struct MoveLinear ml3 = {
-		.startRow = 0, .startCol = 0,
-		.dRow = -3, .dCol = 3,
+		.startRow = 100, .startCol = 100,
+		.dRow = 3, .dCol = 1,
 
-		.callback = MoveRotate, .priv = &mr1,
+		.callback = MoveSpin, .priv = &ms1,
 	};
 	Animation_pushEvent(&anim, 0, 80, MoveLinear, &ml3);
 
-	// Yellow square
+	// White square
 	struct SquareSettings s4 = {
 		.width = 20, .height = 20, .color = 0xFFFFFFFF,
 	};