Add ability to move sprite with d-pad and rotate with L/R flippers

sprite_simple/arm9/source/template.c

@@ -4,13 +4,27 @@
 	- 1D palette-based sprite on both screens using the touchpad for location
 	- We generate the image data(tile map/palette) on our own
 	- OAM is used to manage the sprite data (max of 128 sprites - 32 can be affine-transformed)
+	BONUS:
+	- Move the sprite around with the keypad
+	- Add some rotation with the L/R flippers - sub is double speed of the main
+
+	QUESTIONS:
+	- The movement spills off the screen and continues on the other side. There must be some overflow.
+	  What size are ints on the NDS?
 
 ---------------------------------------------------------------------------------*/
 #include <nds.h>
 
+#define MOVEMENT_RATE			2
+#define ROTATION_RATE			2
+#define SPRITE_DIMENSION_SIZE	16
+
 int main() {
 
 	int i;
+	int currentPosX = (SCREEN_WIDTH - (SPRITE_DIMENSION_SIZE/2)) / 2;
+	int currentPosY = (SCREEN_HEIGHT - (SPRITE_DIMENSION_SIZE/2)) / 2;
+	int angle = degreesToAngle(0);
 	touchPosition touch;
 	u16 *gfx;
 	u16 *gfxSub;
@@ -46,21 +60,56 @@ int main() {
 
 		// check our touch location
 		scanKeys();
-		if(keysHeld() & KEY_TOUCH)
+		if(keysHeld() & KEY_TOUCH) {
 			touchRead(&touch);
+			currentPosX = touch.px;
+			currentPosY = touch.py;
+		}
+		else if(keysHeld() & KEY_UP) {
+			currentPosY -= MOVEMENT_RATE;
+		}
+		else if(keysHeld() & KEY_DOWN) {
+			currentPosY += MOVEMENT_RATE; 
+		}
+		else if(keysHeld() & KEY_LEFT) {
+			currentPosX -= MOVEMENT_RATE;
+		}
+		else if(keysHeld() & KEY_RIGHT) {
+			currentPosX += MOVEMENT_RATE;
+		}
+		else if(keysHeld() & KEY_L) {
+			angle -= degreesToAngle(ROTATION_RATE);
+		}
+		else if(keysHeld() & KEY_R) {
+			angle += degreesToAngle(ROTATION_RATE);
+		}
+
+		oamRotateScale(&oamMain,
+			0,							// rotation ID (we can have up to 32 different affine matrices!)
+			angle,						// angle of the rotation
+			intToFixed(1, 8),			// inverse scale factor of X
+			intToFixed(1, 8)			// inverse scale factor of Y
+			);
+
+		oamRotateScale(&oamSub,
+			0,							// rotation ID (we can have up to 32 different affine matrices!)
+			angle * 2,					// angle of the rotation (double the main screen[0])
+			intToFixed(1, 8),			// inverse scale factor of X
+			intToFixed(1, 8)			// inverse scale factor of Y
+			);
 
 		// set our new OAM data
 		oamSet(&oamMain,
 			0,							// setting the OAM ID
-			touch.px,					// X location of the sprite
-			touch.py,					// Y location of the sprite
+			currentPosX,				// X location of the sprite
+			currentPosY,				// Y location of the sprite
 			0,							// sprite priority
 			0,							// palette index, or alpha value of using a bitmap sprite
 			SpriteSize_16x16, 			// size of the sprite
 			SpriteColorFormat_256Color,	// color format of the sprite
 			gfx,						// address of the sprite data
-			-1,							// affine index of sprite (< 0 or > 31 means unrotated)
-			false,						// double size for rotation?
+			0,							// affine index of sprite (< 0 or > 31 means unrotated)
+			true,						// double size for rotation? (so it doesn't get clipped)
 			false,						// hide the sprite?
 			false,						// V-flip the sprite?
 			false,						// H-flip the sprite?
@@ -69,15 +118,15 @@ int main() {
 
 		oamSet(&oamSub,
 			0,							// setting the OAM ID
-			touch.px,					// X location of the sprite
-			touch.py,					// Y location of the sprite
+			currentPosX,				// X location of the sprite
+			currentPosY,				// Y location of the sprite
 			0,							// sprite priority
 			0,							// palette index, or alpha value of using a bitmap sprite
 			SpriteSize_16x16, 			// size of the sprite
 			SpriteColorFormat_256Color,	// color format of the sprite
 			gfxSub,						// address of the sprite data
-			-1,							// affine index of sprite (< 0 or > 31 means unrotated)
-			false,						// double size for rotation?
+			0,							// affine index of sprite (< 0 or > 31 means unrotated)
+			true,						// double size for rotation? (so it doesn't get clipped)
 			false,						// hide the sprite?
 			false,						// V-flip the sprite?
 			false,						// H-flip the sprite?