From c86e2a8d70f6c8ac1cc89c1d6d06d5011c5a3cef Mon Sep 17 00:00:00 2001
From: N0NameN0 <alonetrio@yahoo.com>
Date: Sat, 7 Nov 2009 13:26:03 +0000
Subject: [PATCH] [ADD] GRRLIB_DrawPart to draw a specific part of a Texture.

---
 GRRLIB/GRRLIB/GRRLIB_render.c      | 86 ++++++++++++++++++++++++++++++
 GRRLIB/GRRLIB/grrlib/GRRLIB__lib.h |  4 ++
 2 files changed, 90 insertions(+)

diff --git a/GRRLIB/GRRLIB/GRRLIB_render.c b/GRRLIB/GRRLIB/GRRLIB_render.c
index dfb963a..1d08102 100644
--- a/GRRLIB/GRRLIB/GRRLIB_render.c
+++ b/GRRLIB/GRRLIB/GRRLIB_render.c
@@ -237,6 +237,92 @@ void  GRRLIB_DrawTile (const f32 xpos, const f32 ypos, const GRRLIB_texImg *tex,
     GX_SetVtxDesc(GX_VA_TEX0,   GX_NONE);
 }
 
+/**
+ * Draw a part of a texture
+ * @param xpos Specifies the x-coordinate of the upper-left corner.
+ * @param ypos Specifies the y-coordinate of the upper-left corner.
+ * @param partx Specifies the x-coordinate of the upper-left corner in the Texture.
+ * @param party Specifies the y-coordinate of the upper-left corner in the Texture.
+ * @param partw Specifies the width in the Texture.
+ * @param parth Specifies the height in the Texture.
+ * @param tex The texture containing the tile to draw.
+ * @param degrees Angle of rotation.
+ * @param scaleX Specifies the x-coordinate scale. -1 could be used for flipping the texture horizontally.
+ * @param scaleY Specifies the y-coordinate scale. -1 could be used for flipping the texture vertically.
+ * @param color Color in RGBA format.
+ * @param frame Specifies the frame to draw.
+ */
+void  GRRLIB_DrawPart (const f32 xpos, const f32 ypos, const f32 partx, const f32 party, const f32 partw, const f32 parth, const GRRLIB_texImg *tex,
+                       const f32 degrees, const f32 scaleX, const f32 scaleY,
+                       const u32 color) {
+    GXTexObj  texObj;
+    f32       width, height;
+    Mtx       m, m1, m2, mv;
+    f32       s1, s2, t1, t2;
+
+    if (tex == NULL || tex->data == NULL)  return ;
+
+    // The 0.001f/x is the frame correction formula by spiffen
+    s1 = (partx /tex->w) +(0.001f /tex->w);
+    s2 = ((partx + partw)/tex->w) -(0.001f /tex->w);
+    t1 = (party /tex->h) +(0.001f /tex->h);
+    t2 = ((party + parth)/tex->h) -(0.001f /tex->h);
+
+    GX_InitTexObj(&texObj, tex->data,
+                  tex->w, tex->h,
+                  GX_TF_RGBA8, GX_CLAMP, GX_CLAMP, GX_FALSE);
+
+    if (GRRLIB_Settings.antialias == false)
+        GX_InitTexObjLOD(&texObj, GX_NEAR, GX_NEAR,
+                         0.0f, 0.0f, 0.0f, 0, 0, GX_ANISO_1);
+
+    GX_LoadTexObj(&texObj,      GX_TEXMAP0);
+    GX_SetTevOp  (GX_TEVSTAGE0, GX_MODULATE);
+    GX_SetVtxDesc(GX_VA_TEX0,   GX_DIRECT);
+
+    width  = partw * 0.5f;
+    height = parth * 0.5f;
+
+    guMtxIdentity  (m1);
+    guMtxScaleApply(m1, m1, scaleX, scaleY, 1.0f);
+    guMtxRotAxisDeg(m2, &axis, degrees);
+    guMtxConcat    (m2, m1, m);
+
+    guMtxTransApply(m, m,
+        xpos +width  +tex->handlex
+            -tex->offsetx +( scaleX *(-tex->handley *sin(-DegToRad(degrees))
+                                      -tex->handlex *cos(-DegToRad(degrees))) ),
+        ypos +height +tex->handley
+            -tex->offsety +( scaleY *(-tex->handley *cos(-DegToRad(degrees))
+                                      +tex->handlex *sin(-DegToRad(degrees))) ),
+        0);
+
+    guMtxConcat(GXmodelView2D, m, mv);
+
+    GX_LoadPosMtxImm(mv, GX_PNMTX0);
+    GX_Begin(GX_QUADS, GX_VTXFMT0, 4);
+        GX_Position3f32(-width, -height, 0);
+        GX_Color1u32   (color);
+        GX_TexCoord2f32(s1, t1);
+
+        GX_Position3f32(width, -height,  0);
+        GX_Color1u32   (color);
+        GX_TexCoord2f32(s2, t1);
+
+        GX_Position3f32(width, height,  0);
+        GX_Color1u32   (color);
+        GX_TexCoord2f32(s2, t2);
+
+        GX_Position3f32(-width, height,  0);
+        GX_Color1u32   (color);
+        GX_TexCoord2f32(s1, t2);
+    GX_End();
+    GX_LoadPosMtxImm(GXmodelView2D, GX_PNMTX0);
+
+    GX_SetTevOp  (GX_TEVSTAGE0, GX_PASSCLR);
+    GX_SetVtxDesc(GX_VA_TEX0,   GX_NONE);
+}
+
 /**
  * Draw a tile in a quad.
  * @param pos Vector array of the 4 points.
diff --git a/GRRLIB/GRRLIB/grrlib/GRRLIB__lib.h b/GRRLIB/GRRLIB/grrlib/GRRLIB__lib.h
index d9d6eb6..4cf108d 100644
--- a/GRRLIB/GRRLIB/grrlib/GRRLIB__lib.h
+++ b/GRRLIB/GRRLIB/grrlib/GRRLIB__lib.h
@@ -111,6 +111,10 @@ void  GRRLIB_DrawTile (const f32 xpos, const f32 ypos, const GRRLIB_texImg *tex,
                        const f32 degrees, const f32 scaleX, const f32 scaleY,
                        const u32 color, const int frame) ;
 
+void  GRRLIB_DrawPart (const f32 xpos, const f32 ypos, const f32 partx, const f32 party, const f32 partw, const f32 parth, const GRRLIB_texImg *tex,
+                       const f32 degrees, const f32 scaleX, const f32 scaleY,
+                       const u32 color);
+
 void  GRRLIB_DrawTileQuad (const guVector pos[4], GRRLIB_texImg *tex,
                            const u32 color, const int frame) ;