starting to merge vulkan with the engine

- refactored scene_main to be able to share code between software and
  hardware renderers, while still sharing code between terminal software
  renderer and graphical software renderer
- made the hardware renderer use scene objects vertices and transforms,
  instead of hardcoded ones
- made the hardware renderer use the scene's camera
- made .obj parser create Vector3 instead of Vector4, which didn't made
  sense
- removed unnecessary std::
- lots of small changes

1 files changed, 19 insertions, 8 deletions

diff --git a/src/shaders/shader.slang b/src/shaders/shader.slang
index 1f055c1..5598e1e 100644
--- a/src/shaders/shader.slang
+++ b/src/shaders/shader.slang
@@ -1,28 +1,28 @@
 struct VertexInput {
     float3 pos;
-    float3 col;
-    float2 uv;
+    float3 normal;
 };
 
 struct UniformBuffer {
     float4x4 model, view, proj;
+    float4x4 camera_rot;
+    float3 camera_loc;
 };
 
 ConstantBuffer<UniformBuffer> ubo;
 
 struct VertexOutput {
     float4 pos : SV_Position;
-    float3 col;
-    float2 uv;
+    float3 world_loc;
+    float3 normal;
 };
 
 [shader("vertex")]
 VertexOutput vert_main(VertexInput vi) {
     VertexOutput vo;
-    // vo.pos = float4(vi.pos, 0., 1.);
     vo.pos = mul(ubo.proj, mul(ubo.view, mul(ubo.model, float4(vi.pos, 1.))));
-    vo.col = vi.col;
-    vo.uv  = vi.uv;
+    vo.world_loc = vi.pos;
+    vo.normal = vi.normal;
     return vo;
 }
 
@@ -30,5 +30,16 @@ Sampler2D texture;
 
 [shader("fragment")]
 float4 frag_main(VertexOutput vo) : SV_Target {
-    return texture.Sample(vo.uv);
+    float3 u = vo.world_loc - ubo.camera_loc;
+    float u_len_sq = dot(u, u);
+    u = normalize(u);
+    float attenuation = dot(mul(ubo.camera_rot, float4(0., 0., -1., 0.)).xyz, u);
+    if (attenuation < .7) attenuation = 0.f;
+    else if (attenuation > .8) attenuation = 1.;
+    else attenuation = (attenuation - .7) / .1;
+    float light = -dot(vo.normal, u) / u_len_sq;
+    if (light < 0.) light = 0.;
+    float final_light = .05 + light * attenuation * .8 * .95;
+    if (final_light > 1.) final_light = 1.;
+    return float4(final_light, final_light, final_light, 1.);
 }