Add alpha scissor

CMakeLists.txt

@@ -27,10 +27,18 @@ target_link_libraries(couch ${LUA_LIBRARIES})
 
 include(UseSWIG)
 set_property(SOURCE scripting/couch.i PROPERTY CPLUSPLUS ON)
+if (NOT WIN32)
 swig_add_library(couchlua
   TYPE SHARED
   LANGUAGE lua
   SOURCES scripting/couch.i scripting/lua/helpers.i)
+else()
+  swig_add_library(couchlua
+  TYPE STATIC
+  LANGUAGE lua
+  SOURCES scripting/couch.i scripting/lua/helpers.i)
+endif()
+
 target_link_libraries(couchlua ${LUA_LIBRARIES})
 target_link_libraries(couch couchlua)
 

core/Material.cpp

@@ -15,8 +15,6 @@ Color::Color(cfloat r, cfloat g, cfloat b) {
 Texture::Texture() {}
 
 Texture Texture::FromFile(const char *filename) {
-  // Lotta hocus pocus
-  // https://learnopengl.com/Getting-started/Textures
   Texture tex;
   glGenTextures(1, &tex.id);
   glBindTexture(GL_TEXTURE_2D, tex.id);
@@ -43,4 +41,5 @@ Texture Texture::FromFile(const char *filename) {
 Material::Material() {
   usesColor = false;
   usesTex = false;
+  alphaScissor = 0.0f;
 }

core/Material.h

@@ -26,6 +26,7 @@ struct Material {
   bool usesColor;
   Texture tex;
   bool usesTex;
+  cfloat alphaScissor;
   Material();
 };
 

core/Mesh.cpp

@@ -35,6 +35,7 @@ void SubMesh::SetupSubMesh() {
 void SubMesh::Draw(Shader *shader) {
   shader->UpdateColor(material.usesColor, material.color);
   shader->UpdateTex(material.usesTex, material.tex);
+  shader->UpdateAlphaScissor(material.alphaScissor);
   glBindVertexArray(VAO);
   glDrawElements(GL_TRIANGLES, indices.size() * 3, GL_UNSIGNED_INT, 0);
   glBindVertexArray(0);
@@ -54,6 +55,10 @@ void Mesh::SetupMesh() {
   }
 }
 
+Material Mesh::GetMaterial(int submesh) {
+  return submeshes[submesh]->material;
+}
+
 void Mesh::SetMaterial(int submesh, Material material) {
   submeshes[submesh]->material = material;
 }

core/Mesh.h

@@ -38,6 +38,7 @@ class Mesh : public Spatial {
 public:
   Mesh();
   ~Mesh();
+  Material GetMaterial(int submesh);
   void SetMaterial(int submesh, Material material);
   static Mesh *FromFile(const char *filename);
   virtual bool IsDrawable() const {return true;}

core/Shaders/FlatShader.cpp

@@ -3,3 +3,5 @@
 #include "flat.frag.h"
 
 FlatShader::FlatShader() : Shader(flat_vert, flat_frag) {}
+
+Name FlatShader::GetName() const {return "Flat Shader";}

core/Shaders/FlatShader.h

@@ -6,6 +6,7 @@
 class FlatShader : public Shader {
 public:
   FlatShader();
+  Name GetName() const;
 };
 
 #endif /* FLATSHADER_H */

core/Shaders/ScreenShader.cpp

@@ -3,3 +3,5 @@
 #include "screen.frag.h"
 
 ScreenShader::ScreenShader() : Shader(screen_vert, screen_frag) {}
+
+Name ScreenShader::GetName() const {return "Screen Shader";}

core/Shaders/ScreenShader.h

@@ -3,4 +3,5 @@
 class ScreenShader : public Shader {
 public:
   ScreenShader();
+  Name GetName() const;
 };

core/Shaders/Shader.cpp

@@ -69,6 +69,9 @@ void Shader::UpdateTex(bool usesTex, Texture tex) {
   glUniform1i(glGetUniformLocation(id, "material.usesTex"), (int) usesTex);
   glBindTexture(GL_TEXTURE_2D, tex.id);
 }
+void Shader::UpdateAlphaScissor(cfloat alphaScissor) {
+  glUniform1f(glGetUniformLocation(id, "material.alphaScissor"), alphaScissor);
+}
 
 Name Shader::GetName() const {
   return "Unnamed Shader";

core/Shaders/Shader.h

@@ -19,6 +19,7 @@ public:
   void UpdateColor(bool usesColor, Color color);
   void UpdateTex(bool usesTex);
   void UpdateTex(bool usesTex, Texture tex);
+  void UpdateAlphaScissor(cfloat alphaScissor);
 
   virtual Name GetName() const;
 };

demo/main.lua

@@ -52,6 +52,15 @@ function init()
    trough.transform.scale = trough.transform.scale * 3.0
 
    scaffold = couch.TexturedMesh("scaffold.glb", "grate_floor_lowres.png", "railing.png")
+   
+   material = scaffold:GetMaterial(0)
+   material.alphaScissor = 0.9
+   scaffold:SetMaterial(0, material)
+
+   material = scaffold:GetMaterial(1)
+   material.alphaScissor = 0.1
+   scaffold:SetMaterial(1, material)
+   
    couch.Node.GetRoot().children:Append(scaffold)
    scaffold.transform:Translate(-10.0, 0.0, 0.0)
 end

shaders/flat.frag

@@ -2,24 +2,27 @@
 
 in vec3 UV;
 
+out vec4 FragColor;
+
 struct Material {
   vec3 color;
   bool usesColor;
   sampler2D tex;
   bool usesTex;
+  float alphaScissor;
 };
 
 uniform Material material;
 
 void main() {
-  gl_FragColor = vec4(0.0);
+  FragColor = vec4(0.0);
   if (material.usesColor) {
-    gl_FragColor += vec4(material.color, 1.0);
+    FragColor += vec4(material.color, 1.0);
   }
   if (material.usesTex) {
-    gl_FragColor += texture(material.tex, UV.xy / UV.z);
+    FragColor += texture(material.tex, UV.xy / UV.z);
   }
-  if (gl_FragColor.w < 0.99) {
+  if (FragColor.w < material.alphaScissor) {
     discard;
   }
 }