3 files changed, 61 insertions, 0 deletions
diff --git a/source/lessons/stencil_testing/shaders/depth_test.fs.glsl b/source/lessons/stencil_testing/shaders/depth_test.fs.glsl
new file mode 100644
index 0000000..796d849
--- /dev/null
+++ b/source/lessons/stencil_testing/shaders/depth_test.fs.glsl
@@ -0,0 +1,30 @@
+#version 330 core
+
+
+in vec2 TexCoords;
+in vec3 VertexWorldPos;
+uniform sampler2D TexId;
+out vec4 FragColor;
+
+uniform float near = 0.1f;
+uniform float far = 100.0f;
+
+/* @note
+float linear_fragment_depth = MakeDepthLinear(non_linear_fragment_depth);
+float scaled_lfd = linear_fragment_depth/far;
+
+gives us the z value in eye space.
+This is purely for learning purposes.
+The equation used in MakeDepthLinear is derived from the PerspectiveProjectionMatrix.
+Take a look at the equation for that in the codebase 
+or here: https://www.songho.ca/opengl/gl_projectionmatrix.html
+*/
+float MakeDepthLinear(float depth) {
+  float ndc = 2.0f*depth - 1;
+  float linear_depth = (2.0 * far * near)/(far + near - ndc*(far - near));
+  return linear_depth;
+}
+
+void main() {
+    FragColor = texture(TexId, TexCoords);
+}
diff --git a/source/lessons/stencil_testing/shaders/depth_test.vs.glsl b/source/lessons/stencil_testing/shaders/depth_test.vs.glsl
new file mode 100644
index 0000000..b3b81cc
--- /dev/null
+++ b/source/lessons/stencil_testing/shaders/depth_test.vs.glsl
@@ -0,0 +1,19 @@
+#version 330 core
+layout(location=0) in vec3 aPos;
+layout(location=1) in vec2 aTex;
+
+uniform mat4 Model;
+uniform mat4 View;
+uniform mat4 Projection;
+
+out vec2 TexCoords;
+out vec3 VertexWorldPos;
+
+// @note: I still do not fully understand how the FragNormal calculation works. Need to make sure I intuitively 
+// get that
+
+void main() {
+  gl_Position = Projection*View*Model*vec4(aPos, 1.0);
+  VertexWorldPos = vec3(Model * vec4(aPos, 1.0));
+  TexCoords = aTex;
+};
diff --git a/source/lessons/stencil_testing/shaders/stencil_outline.fs.glsl b/source/lessons/stencil_testing/shaders/stencil_outline.fs.glsl
new file mode 100644
index 0000000..63d6a75
--- /dev/null
+++ b/source/lessons/stencil_testing/shaders/stencil_outline.fs.glsl
@@ -0,0 +1,12 @@
+#version 330 core
+
+
+in vec2 TexCoords;
+in vec3 VertexWorldPos;
+uniform sampler2D TexId;
+uniform vec4 hlt_color;
+out vec4 FragColor;
+
+void main() {
+    FragColor = hlt_color;
+}