From e1d5eba1f2cd21c04798192cdf8e0f1c91c6cfb0 Mon Sep 17 00:00:00 2001
From: kichikuou <KichikuouChrome@gmail.com>
Date: Sun, 11 Jun 2023 13:37:09 +0900
Subject: [PATCH] Implement DrawGraph.CopyRotZoom2Bilinear

Used in Daiteikoku.

It's similar to DrawGraph.CopyRotZoom, but specifies source and
destination center points.
---
 include/gfx/gfx.h   |  1 +
 src/draw.c          | 23 +++++++++++++++++++++++
 src/hll/DrawGraph.c |  7 +++++--
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/include/gfx/gfx.h b/include/gfx/gfx.h
index 0c6c9c0..614e4a1 100644
--- a/include/gfx/gfx.h
+++ b/include/gfx/gfx.h
@@ -146,6 +146,7 @@ void gfx_copy_stretch_blend_amap_alpha(struct texture *dst, int dx, int dy, int
 void gfx_copy_rot_zoom(Texture *dst, Texture *src, int sx, int sy, int w, int h, float rotate, float mag);
 void gfx_copy_rot_zoom_amap(Texture *dst, Texture *src, int sx, int sy, int w, int h, float rotate, float mag);
 void gfx_copy_rot_zoom_use_amap(Texture *dst, Texture *src, int sx, int sy, int w, int h, float rotate, float mag);
+void gfx_copy_root_zoom2(Texture *dst, float cx, float cy, Texture *src, float scx, float scy, float rot, float mag);
 void gfx_copy_reverse_LR(Texture *dst, int dx, int dy, Texture *src, int sx, int sy, int w, int h);
 void gfx_copy_reverse_amap_LR(Texture *dst, int dx, int dy, Texture *src, int sx, int sy, int w, int h);
 void gfx_copy_rotate_y(Texture *dst, Texture *front, Texture *back, int sx, int sy, int w, int h, float rot, float mag);
diff --git a/src/draw.c b/src/draw.c
index ec8caf9..23ac847 100644
--- a/src/draw.c
+++ b/src/draw.c
@@ -770,6 +770,29 @@ void gfx_copy_rot_zoom_use_amap(Texture *dst, Texture *src, int sx, int sy, int
 	copy_rot_zoom(dst, src, sx, sy, w, h, rotate, mag, &hitbox_shader.s);
 }
 
+void gfx_copy_root_zoom2(Texture *dst, float cx, float cy, Texture *src, float scx, float scy, float rot, float mag)
+{
+	gfx_fill_amap(dst, 0, 0, dst->w, dst->h, 0);
+
+	// 1. scale src vertices to texture size
+	// 2. translate so that center point of copy region is at origin
+	// 3. rotate
+	// 4. scale
+	// 4. tranlate to center point of dst texture
+	// (applied in reverse order)
+	mat4 mw_transform = GLM_MAT4_IDENTITY_INIT;
+	glm_translate(mw_transform, (vec3){ cx, cy, 0 });
+	glm_scale(mw_transform, (vec3){ mag, mag, 0 });
+	glm_rotate_z(mw_transform, -rot * (M_PI/180.0), mw_transform);
+	glm_translate(mw_transform, (vec3){ -scx, -scy, 0 });
+	glm_scale(mw_transform, (vec3){ src->w, src->h, 1 });
+
+	mat4 wv_transform = WV_TRANSFORM(dst->w, dst->h);
+
+	struct copy_data data = ROTATE_DATA(dst, 0, 0, src->w, src->h);
+	run_draw_shader(&hitbox_noblend_shader.s, dst, src, mw_transform, wv_transform, &data);
+}
+
 static void copy_rotate_y(Texture *dst, Texture *front, Texture *back, int sx, int sy, int w, int h, float rot, float mag, Shader *shader)
 {
 	Texture *src = front;
diff --git a/src/hll/DrawGraph.c b/src/hll/DrawGraph.c
index 729e83b..984181d 100644
--- a/src/hll/DrawGraph.c
+++ b/src/hll/DrawGraph.c
@@ -298,7 +298,10 @@ static void DrawGraph_CopyRotZoomUseAMap(int dst, int src, int sx, int sy, int w
 	gfx_copy_rot_zoom_use_amap(DTEX(dst), STEX(src), sx, sy, w, h, rotate, mag);
 }
 
-//void DrawGraph_CopyRotZoom2Bilinear(int dst, float cx, float cy, int src, float scx, float scy, float rot, float mag);
+static void DrawGraph_CopyRotZoom2Bilinear(int dst, float cx, float cy, int src, float scx, float scy, float rot, float mag)
+{
+	gfx_copy_root_zoom2(DTEX(dst), cx, cy, STEX(src), scx, scy, rot, mag);
+}
 
 static void DrawGraph_CopyRotateY(int write, int dst, int src, int sx, int sy, int w, int h, float rot, float mag)
 {
@@ -469,7 +472,7 @@ HLL_LIBRARY(DrawGraph,
 	    HLL_EXPORT(CopyRotZoom, DrawGraph_CopyRotZoom),
 	    HLL_EXPORT(CopyRotZoomAMap, DrawGraph_CopyRotZoomAMap),
 	    HLL_EXPORT(CopyRotZoomUseAMap, DrawGraph_CopyRotZoomUseAMap),
-	    //HLL_EXPORT(CopyRotZoom2Bilinear, DrawGraph_CopyRotZoom2Bilinear),
+	    HLL_EXPORT(CopyRotZoom2Bilinear, DrawGraph_CopyRotZoom2Bilinear),
 	    HLL_EXPORT(CopyRotateY, DrawGraph_CopyRotateY),
 	    HLL_EXPORT(CopyRotateYUseAMap, DrawGraph_CopyRotateYUseAMap),
 	    //HLL_EXPORT(CopyRotateYFixL, DrawGraph_CopyRotateYFixL),