From 27e5d0bdca7fd113788f8f37f1b74cb3c8affd7f Mon Sep 17 00:00:00 2001
From: hyzboy <hyzboy@gmail.com>
Date: Wed, 25 Jun 2025 02:04:36 +0800
Subject: [PATCH] =?UTF-8?q?Billboard=20Shader=E5=A2=9E=E5=8A=A0=E5=8F=AF?=
 =?UTF-8?q?=E6=8C=87=E5=AE=9A=E6=AD=A3=E9=9D=A2=E4=B8=BA=E9=A1=BA=E6=97=B6?=
 =?UTF-8?q?=E9=92=88/=E9=80=86=E6=97=B6=E9=92=88?=
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Content-Transfer-Encoding: 8bit

---
 inc/hgl/graph/mtl/Material3DCreateConfig.h  |  2 ++
 src/ShaderGen/3d/M_BillboardDynamicSize.cpp | 17 ++++++-------
 src/ShaderGen/3d/M_BillboardFixedSize.cpp   | 17 ++++++-------
 src/ShaderGen/3d/S_BillboardVertex.h        | 28 +++++++++++++++++++++
 4 files changed, 46 insertions(+), 18 deletions(-)
 create mode 100644 src/ShaderGen/3d/S_BillboardVertex.h

diff --git a/inc/hgl/graph/mtl/Material3DCreateConfig.h b/inc/hgl/graph/mtl/Material3DCreateConfig.h
index d9847ad3..97aed9bd 100644
--- a/inc/hgl/graph/mtl/Material3DCreateConfig.h
+++ b/inc/hgl/graph/mtl/Material3DCreateConfig.h
@@ -66,6 +66,8 @@ struct BillboardMaterialCreateConfig:public Material3DCreateConfig
 
     Vector2u    pixel_size;             ///<像素尺寸
 
+    VkFrontFace front_face=VK_FRONT_FACE_CLOCKWISE; ///<正面朝向
+
 public:
 
     using Material3DCreateConfig::Material3DCreateConfig;
diff --git a/src/ShaderGen/3d/M_BillboardDynamicSize.cpp b/src/ShaderGen/3d/M_BillboardDynamicSize.cpp
index 12c8f484..1acda133 100644
--- a/src/ShaderGen/3d/M_BillboardDynamicSize.cpp
+++ b/src/ShaderGen/3d/M_BillboardDynamicSize.cpp
@@ -1,4 +1,5 @@
 #include"Std3DMaterial.h"
+#include"S_BillboardVertex.h"
 #include<hgl/shadergen/MaterialCreateInfo.h>
 
 STD_MTL_NAMESPACE_BEGIN
@@ -14,14 +15,6 @@ void main()
     constexpr const char gs_main[]=R"(
 void main()
 {
-    const vec2 BillboardVertex[4]=vec2[]
-    (
-        vec2(-0.5,-0.5),
-        vec2( 0.5,-0.5),
-        vec2(-0.5, 0.5),
-        vec2( 0.5, 0.5)
-    );
-
     mat4 MVPMatrix=camera.vp*l2w.mats[Input[0].l2w_id];
 
     for(int i=0;i<4;i++)
@@ -48,9 +41,14 @@ void main()
 
     class MaterialBillboard2DDynamicSize:public Std3DMaterial
     {
+        mtl::BillboardMaterialCreateConfig *billboard_config;
+
     public:
 
-        using Std3DMaterial::Std3DMaterial;
+        MaterialBillboard2DDynamicSize(mtl::BillboardMaterialCreateConfig *bcfg):Std3DMaterial(bcfg)
+        {
+            billboard_config=bcfg;
+        }
         ~MaterialBillboard2DDynamicSize()=default;
 
         bool CustomVertexShader(ShaderCreateInfoVertex *vsc) override
@@ -70,6 +68,7 @@ void main()
 
             gsc->AddOutput(SVT_VEC2,"TexCoord");
 
+            gsc->AddUserData(billboard_config->front_face==VK_FRONT_FACE_CLOCKWISE?shader_billboard_vertex_cw:shader_billboard_vertex_ccw);
             gsc->SetMain(gs_main);
             return(true);
         }
diff --git a/src/ShaderGen/3d/M_BillboardFixedSize.cpp b/src/ShaderGen/3d/M_BillboardFixedSize.cpp
index 0d012674..84efab4c 100644
--- a/src/ShaderGen/3d/M_BillboardFixedSize.cpp
+++ b/src/ShaderGen/3d/M_BillboardFixedSize.cpp
@@ -1,4 +1,5 @@
 #include"Std3DMaterial.h"
+#include"S_BillboardVertex.h"
 #include<hgl/shadergen/MaterialCreateInfo.h>
 
 STD_MTL_NAMESPACE_BEGIN
@@ -21,14 +22,6 @@ void main()
     constexpr const char gs_main[]=R"(
 void main()
 {
-    const vec2 BillboardVertex[4]=vec2[]
-    (
-        vec2(-0.5,-0.5),
-        vec2(-0.5, 0.5),
-        vec2( 0.5,-0.5),
-        vec2( 0.5, 0.5)
-    );
-
     for(int i=0;i<4;i++)
     {
         gl_Position=gl_in[0].gl_Position;
@@ -49,9 +42,14 @@ void main()
 
     class MaterialBillboard2DFixedSize:public Std3DMaterial
     {
+        mtl::BillboardMaterialCreateConfig *billboard_config;
+
     public:
 
-        using Std3DMaterial::Std3DMaterial;
+        MaterialBillboard2DFixedSize(mtl::BillboardMaterialCreateConfig *bcfg):Std3DMaterial(bcfg)
+        {
+            billboard_config=bcfg;
+        }
         ~MaterialBillboard2DFixedSize()=default;
 
         bool CustomVertexShader(ShaderCreateInfoVertex *vsc) override
@@ -71,6 +69,7 @@ void main()
 
             gsc->AddOutput(SVT_VEC2,"TexCoord");
 
+            gsc->AddUserData(billboard_config->front_face==VK_FRONT_FACE_CLOCKWISE?shader_billboard_vertex_cw:shader_billboard_vertex_ccw);
             gsc->SetMain(gs_main);
             return(true);
         }
diff --git a/src/ShaderGen/3d/S_BillboardVertex.h b/src/ShaderGen/3d/S_BillboardVertex.h
new file mode 100644
index 00000000..5b660aa4
--- /dev/null
+++ b/src/ShaderGen/3d/S_BillboardVertex.h
@@ -0,0 +1,28 @@
+#pragma once
+#include<hgl/graph/mtl/StdMaterial.h>
+
+STD_MTL_NAMESPACE_BEGIN
+
+// 注意：走的几何Shader，输出是三角形条
+
+constexpr const char shader_billboard_vertex_ccw[]=R"(
+const vec2 BillboardVertex[4]=vec2[]
+(
+    vec2(-0.5,-0.5),
+    vec2(-0.5, 0.5),
+    vec2( 0.5,-0.5),
+    vec2( 0.5, 0.5)
+);
+)";
+
+constexpr const char shader_billboard_vertex_cw[]=R"(
+const vec2 BillboardVertex[4]=vec2[]
+(
+    vec2(-0.5,-0.5),
+    vec2( 0.5,-0.5),
+    vec2(-0.5, 0.5),
+    vec2( 0.5, 0.5)
+);
+)";
+
+STD_MTL_NAMESPACE_END