From 0c4205acbb3526b9f10f8c0adf8f8bdbbadd95e3 Mon Sep 17 00:00:00 2001
From: Isuru Samarathunga <isuru.00.aravinda@gmail.com>
Date: Sat, 13 Sep 2025 23:33:26 +0530
Subject: [PATCH] Depth Buffer

---
 Src/IAESandbox/imp/cpp/Game.cpp               |  7 +++--
 .../imp/cpp/Rendering/Pipeline/UnlitMesh.cpp  | 14 +++++++++
 Src/IAEngine/imp/cpp/Rendering/Renderer.cpp   | 30 +++++++++++++++++--
 3 files changed, 47 insertions(+), 4 deletions(-)

diff --git a/Src/IAESandbox/imp/cpp/Game.cpp b/Src/IAESandbox/imp/cpp/Game.cpp
index 8a9e344..1e8c0c2 100644
--- a/Src/IAESandbox/imp/cpp/Game.cpp
+++ b/Src/IAESandbox/imp/cpp/Game.cpp
@@ -9,6 +9,7 @@ namespace ia::iae::game
     RefPtr<iae::Scene> scene;
 
     Texture g_tex;
+    Texture g_tex2;
 
     VOID Game::Initialize()
     {
@@ -17,6 +18,7 @@ namespace ia::iae::game
 
         const auto d = File::ReadToVector("Graphics/1.jpg");
         g_tex = Engine::CreateTexture(d.data(), d.size());
+        g_tex2 = Engine::CreateTexture(d.data(), d.size());
     }
 
     VOID Game::Terminate()
@@ -25,7 +27,8 @@ namespace ia::iae::game
 
     VOID Game::Update()
     {
-        g_tex.Draw({200.0f, 150.0f, 0.0f}, {1.0f, 1.0f, 1.0f}, 0.0f, false, false, {1.0f, 1.0f, 1.0f, 1.0f});
-        iae::Renderer::GetCamera()->Position().x += 0.1f;
+        g_tex.Draw({200.0f, 150.0f, 10.0f}, {1.0f, 1.0f, 1.0f}, 0.0f, false, false, {1.0f, 1.0f, 1.0f, 1.0f});
+        g_tex2.Draw({300.0f, 150.0f, 15.0f}, {1.0f, 1.0f, 1.0f}, 0.0f, false, false, {1.0f, 0.0f, 1.0f, 1.0f});
+        //iae::Renderer::GetCamera()->Position().x += 0.1f;
     }
 }
\ No newline at end of file
diff --git a/Src/IAEngine/imp/cpp/Rendering/Pipeline/UnlitMesh.cpp b/Src/IAEngine/imp/cpp/Rendering/Pipeline/UnlitMesh.cpp
index ebb8d87..d062d79 100644
--- a/Src/IAEngine/imp/cpp/Rendering/Pipeline/UnlitMesh.cpp
+++ b/Src/IAEngine/imp/cpp/Rendering/Pipeline/UnlitMesh.cpp
@@ -62,10 +62,24 @@ namespace ia::iae
                                         .num_vertex_attributes =
                                             sizeof(vertexAttributes) / sizeof(vertexAttributes[0])},
             .primitive_type = SDL_GPU_PRIMITIVETYPE_TRIANGLELIST,
+            .rasterizer_state = SDL_GPURasterizerState{
+				.fill_mode = SDL_GPU_FILLMODE_FILL,
+				.cull_mode = SDL_GPU_CULLMODE_NONE,
+				.front_face = SDL_GPU_FRONTFACE_COUNTER_CLOCKWISE
+			},
+            .depth_stencil_state = SDL_GPUDepthStencilState{
+				.compare_op = SDL_GPU_COMPAREOP_LESS,
+				.write_mask = 0xFF,
+				.enable_depth_test = true,
+				.enable_depth_write = true,
+				.enable_stencil_test = false
+			},
             .target_info =
                 {
                     .color_target_descriptions = colorTargets,
                     .num_color_targets = sizeof(colorTargets) / sizeof(colorTargets[0]),
+				    .depth_stencil_format = SDL_GPU_TEXTUREFORMAT_D16_UNORM,
+                    .has_depth_stencil_target = true
                 },
         };
 
diff --git a/Src/IAEngine/imp/cpp/Rendering/Renderer.cpp b/Src/IAEngine/imp/cpp/Rendering/Renderer.cpp
index fabde9f..904d23a 100644
--- a/Src/IAEngine/imp/cpp/Rendering/Renderer.cpp
+++ b/Src/IAEngine/imp/cpp/Rendering/Renderer.cpp
@@ -41,6 +41,7 @@ namespace ia::iae
     SDL_GPUCommandBuffer *g_cmdBuffer{};
     SDL_GPURenderPass *g_renderPass{};
     SDL_GPUTexture *g_swpChainTexture{};
+    SDL_GPUTexture *g_depthBufferTexture{};
 
     // ImGUI State
     ImGuiIO g_imGUIIO{};
@@ -96,13 +97,26 @@ namespace ia::iae
         if (!GPUBuffer::InitializeStagingBuffer())
             return false;
 
+        {
+            SDL_GPUTextureCreateInfo createInfo{.type = SDL_GPU_TEXTURETYPE_2D,
+                                                .format = SDL_GPU_TEXTUREFORMAT_D16_UNORM,
+                                                .usage = SDL_GPU_TEXTUREUSAGE_SAMPLER |
+                                                         SDL_GPU_TEXTUREUSAGE_DEPTH_STENCIL_TARGET,
+                                                .width  = (UINT32)s_width,
+                                                .height = (UINT32)s_height,
+                                                .layer_count_or_depth = 1,
+                                                .num_levels = 1,
+                                                .sample_count = SDL_GPU_SAMPLECOUNT_1};
+            g_depthBufferTexture = SDL_CreateGPUTexture(g_gpuDevice, &createInfo);
+        }
+
         GPUTexture::Initialize();
 
         g_pipelineUnlitMesh = Pipeline_UnlitMesh::Create();
 
         QuadMesh::Initialize();
 
-        matProjection = glm::orthoLH(0.0f, (FLOAT32) s_width, (FLOAT32) s_height, 0.0f, -0.1f, 100.0f);
+        matProjection = glm::orthoLH(0.0f, (FLOAT32) s_width, (FLOAT32) s_height, 0.0f, -1000.0f, 1000.0f);
 
         return true;
     }
@@ -119,6 +133,8 @@ namespace ia::iae
 
         GPUBuffer::TerminateStagingBuffer();
 
+        SDL_ReleaseGPUTexture(g_gpuDevice, g_depthBufferTexture);
+
         ImGui_ImplSDL3_Shutdown();
         ImGui_ImplSDLGPU3_Shutdown();
         ImGui::DestroyContext();
@@ -174,7 +190,17 @@ namespace ia::iae
         colorTargetInfo.load_op = SDL_GPU_LOADOP_CLEAR;
         colorTargetInfo.store_op = SDL_GPU_STOREOP_STORE;
 
-        g_renderPass = SDL_BeginGPURenderPass(g_cmdBuffer, &colorTargetInfo, 1, NULL);
+        SDL_GPUDepthStencilTargetInfo depthStencilTargetInfo = {0};
+        depthStencilTargetInfo.texture = g_depthBufferTexture;
+        depthStencilTargetInfo.cycle = true;
+        depthStencilTargetInfo.clear_depth = 1;
+        depthStencilTargetInfo.clear_stencil = 0;
+        depthStencilTargetInfo.load_op = SDL_GPU_LOADOP_CLEAR;
+        depthStencilTargetInfo.store_op = SDL_GPU_STOREOP_STORE;
+        depthStencilTargetInfo.stencil_load_op = SDL_GPU_LOADOP_CLEAR;
+        depthStencilTargetInfo.stencil_store_op = SDL_GPU_STOREOP_STORE;
+
+        g_renderPass = SDL_BeginGPURenderPass(g_cmdBuffer, &colorTargetInfo, 1, &depthStencilTargetInfo);
 
         g_pipelineUnlitMesh->Bind((Handle) g_renderPass);
         SDL_PushGPUVertexUniformData(g_cmdBuffer, 0, &matProjection, sizeof(matProjection));