initial commit!

libs/libgccvb/affine.c

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+#include "types.h"
+#include "affine.h"
+
+
+// clear a world's affine param table based on world height
+void affine_clr_param(u8 world) {
+	int i,tmp;
+	s16 *param;
+
+	tmp = (world<<4);
+	param = (s16*)((WAM[tmp+9]<<1)+0x00020000);
+	for (i = 0; i < (WAM[tmp+8]<<3); i++) param[i]=0;
+}
+
+// scale an affine background
+// world: number of the world to apply scaling to, must be using affine BGM
+// centerX/centerY: center point (relative to the world) to scale around.
+// imageW/imageH: original image width and height
+// scaleX/scaleY: scale factor per axis.
+//   lowest positive:  0.0156254
+//   highest positive: 512
+//   lowest negative:  -512
+//   highest negative: -0.015625
+// '1' is 100% scale, '2' is 200%, '0.05' is 5%, etc
+void affine_scale(u8 world, s16 centerX, s16 centerY, u16 imageW, u16 imageH, float scaleX, float scaleY) {
+	int i,tmp;
+	s16 *param;
+	f16 XSrc,XScl,YScl;
+	f32 YSrc;
+
+	tmp = (world<<4);
+	param = (s16*)((WAM[tmp+9]<<1)+0x00020000);
+
+	XScl = inverse_fixed(scaleX);
+	YScl = inverse_fixed(scaleY);
+
+	XSrc = -fixed_13_3((centerX-((imageW*scaleX)/2))/scaleX); //keep image centered
+	YSrc = -fixed_7_9((centerY-((imageH*scaleY)/2))/scaleY);
+
+	i=0;
+	while (i < (int)(WAM[tmp+8]<<3)) {
+		param[i++] = XSrc;		//XSrc
+		i++;					//Prlx
+		param[i++] = (YSrc>>6);	//YSrc -- convert from 7.9 to 13.3 fixed
+		param[i++] = XScl; 		//XScl
+		i+=4; //skip remaining entries
+
+		YSrc += YScl; //grab value of next scanline
+	}
+}
+
+// scale an affine background
+// world: number of the world to apply scaling to, must be using affine BGM
+// scale: scale factor.
+//   lowest positive:  0.0156254
+//   highest positive: 512
+//   lowest negative:  -512
+//   highest negative: -0.015625
+// '1' is 100% scale, '2' is 200%, '0.05' is 5%, etc
+void affine_fast_scale(u8 world, float scale) {
+	int i,tmp;
+	s16 *param;
+	f16 XScl,YScl;
+	f32 YSrc;
+
+	tmp = (world<<4);
+	param = (s16*)((WAM[tmp+9]<<1)+0x00020000);
+
+	XScl = YScl = inverse_fixed(scale);
+	YSrc = 0;
+
+	i=0;
+	while (i < (int)(WAM[tmp+8]<<3)) {
+		param[i++] = 0;			//XSrc
+		i++;					//Prlx
+		param[i++] = (YSrc>>6);	//YSrc -- convert from 7.9 to 13.3 fixed
+		param[i++] = XScl; 		//XScl
+		i+=4; //skip remaining entries
+
+		YSrc += YScl; //grab value of next scanline
+	}
+}