1 files changed, 204 insertions, 0 deletions
diff --git a/archive/src/systems/terrain.c b/archive/src/systems/terrain.c
new file mode 100644
index 0000000..069000e
--- /dev/null
+++ b/archive/src/systems/terrain.c
@@ -0,0 +1,204 @@
+/**
+ * @brief
+ */
+#include "terrain.h"
+#include <assert.h>
+#include "file.h"
+#include "glad/glad.h"
+#include "log.h"
+#include "maths.h"
+#include "mem.h"
+#include "ral_common.h"
+#include "ral_impl.h"
+#include "ral_types.h"
+#include "render.h"
+#include "shader_layouts.h"
+#include "str.h"
+
+#define TERRAIN_GRID_U 505
+#define TERRAIN_GRID_V 505
+
+bool Terrain_Init(Terrain_Storage* storage) {
+  storage->grid_dimensions = u32x2(TERRAIN_GRID_U, TERRAIN_GRID_V);
+  storage->hmap_loaded = false;
+
+  GPU_RenderpassDesc rpass_desc = {
+    .default_framebuffer = true,
+  };
+  storage->hmap_renderpass = GPU_Renderpass_Create(rpass_desc);
+
+  arena scratch = arena_create(malloc(1024 * 1024), 1024 * 1024);
+
+  Str8 vert_path = str8("assets/shaders/terrain.vert");
+  Str8 frag_path = str8("assets/shaders/terrain.frag");
+  str8_opt vertex_shader = str8_from_file(&scratch, vert_path);
+  str8_opt fragment_shader = str8_from_file(&scratch, frag_path);
+  if (!vertex_shader.has_value || !fragment_shader.has_value) {
+    ERROR_EXIT("Failed to load shaders from disk")
+  }
+
+  ShaderDataLayout camera_data = Binding_Camera_GetLayout(NULL);
+  ShaderDataLayout terrain_data = TerrainUniforms_GetLayout(NULL);
+
+  GraphicsPipelineDesc pipeline_desc = {
+    .debug_name = "terrain rendering pipeline",
+    .vertex_desc = static_3d_vertex_description(),
+    .data_layouts = { camera_data, terrain_data },
+    .data_layouts_count = 2,
+    .vs = {
+      .debug_name = "terrain vertex shader",
+      .filepath = vert_path,
+      .code = vertex_shader.contents,
+    },
+    .fs = {
+      .debug_name = "terrain fragment shader",
+      .filepath = frag_path,
+      .code = fragment_shader.contents,
+    },
+    .wireframe = false,
+  };
+  storage->hmap_pipeline = GPU_GraphicsPipeline_Create(pipeline_desc, storage->hmap_renderpass);
+
+  storage->texture = TextureLoadFromFile("assets/demo/textures/grass2.png");
+
+  return true;
+}
+
+void Terrain_Shutdown(Terrain_Storage* storage) {}
+
+void Terrain_LoadHeightmap(Terrain_Storage* storage, Heightmap hmap, f32 grid_scale,
+                           bool free_on_upload) {
+  // If there's a current one we will delete it and reallocate buffers
+  if (storage->hmap_loaded) {
+    GPU_BufferDestroy(storage->vertex_buffer);
+    GPU_BufferDestroy(storage->index_buffer);
+  }
+
+  u32 width = hmap.pixel_dimensions.x;
+  u32 height = hmap.pixel_dimensions.y;
+  storage->grid_scale = grid_scale;
+
+  size_t num_vertices = storage->grid_dimensions.x * storage->grid_dimensions.y;
+  storage->num_vertices = num_vertices;
+
+  Vertex_darray* vertices = Vertex_darray_new(num_vertices);
+  u32 index = 0;
+  for (u32 i = 0; i < storage->grid_dimensions.x; i++) {
+    for (u32 j = 0; j < storage->grid_dimensions.y; j++) {
+      size_t position = j * storage->grid_dimensions.x + i;
+      u8* bytes = hmap.image_data;
+      u8 channel = bytes[position];
+      float value = (float)channel / 255.0;
+      // printf("(%d, %d) %d : %f \n", i, j, channel, value);
+
+      assert(index < num_vertices);
+      f32 height = Heightmap_HeightXZ(&hmap, i, j);
+      Vec3 v_pos = vec3_create(i * grid_scale, height, j * grid_scale);
+      Vec3 v_normal = VEC3_Y;
+      float tiling_factor = 505.0f;
+      Vec2 v_uv = vec2((f32)i / width * tiling_factor, (f32)j / height * tiling_factor);
+      Vertex v = { .static_3d = { .position = v_pos, .normal = v_normal, .tex_coords = v_uv } };
+      Vertex_darray_push(vertices, v);
+      index++;
+    }
+  }
+  BufferHandle vertices_handle = GPU_BufferCreate(num_vertices * sizeof(Vertex), BUFFER_VERTEX,
+                                                  BUFFER_FLAG_GPU, vertices->data);
+  storage->vertex_buffer = vertices_handle;
+
+  u32 quad_count = (width - 1) * (height - 1);
+  u32 indices_count = quad_count * 6;
+  storage->indices_count = indices_count;
+  u32_darray* indices = u32_darray_new(indices_count);
+  for (u32 i = 0; i < (width - 1); i++) {     // row
+    for (u32 j = 0; j < (height - 1); j++) {  // col
+      u32 bot_left = i * width + j;
+      u32 top_left = (i + 1) * width + j;
+      u32 top_right = (i + 1) * width + (j + 1);
+      u32 bot_right = i * width + j + 1;
+
+      // top left tri
+      u32_darray_push(indices, top_right);
+      u32_darray_push(indices, top_left);
+      u32_darray_push(indices, bot_left);
+
+      // bottom right tri
+      u32_darray_push(indices, bot_right);
+      u32_darray_push(indices, top_right);
+      u32_darray_push(indices, bot_left);
+    }
+  }
+
+  BufferHandle indices_handle =
+      GPU_BufferCreate(indices_count * sizeof(u32), BUFFER_INDEX, BUFFER_FLAG_GPU, indices->data);
+  storage->index_buffer = indices_handle;
+}
+
+Heightmap Heightmap_FromImage(Str8 filepath) {
+  size_t max_size = MB(16);
+  arena arena = arena_create(malloc(max_size), max_size);
+  // str8_opt maybe_file = str8_from_file(&arena, filepath);
+  // assert(maybe_file.has_value);
+
+  TextureData hmap_tex = TextureDataLoad(Str8_to_cstr(&arena, filepath), false);
+
+  // arena_free_storage(&arena);
+
+  return (Heightmap){
+    .pixel_dimensions = hmap_tex.description.extents,
+    .filepath = filepath,
+    .image_data = hmap_tex.image_data,
+    .num_channels = hmap_tex.description.num_channels,
+    .is_uploaded = false,
+  };
+}
+
+void Terrain_Draw(Terrain_Storage* storage) {
+  GPU_CmdEncoder* enc = GPU_GetDefaultEncoder();
+  GPU_EncodeBindPipeline(enc, storage->hmap_pipeline);
+  RenderScene* scene = Render_GetScene();
+
+  Mat4 view, proj;
+  u32x2 dimensions = GPU_Swapchain_GetDimensions();
+  Camera_ViewProj(&scene->camera, (f32)dimensions.x, (f32)dimensions.y, &view, &proj);
+  Binding_Camera camera_data = { .view = view,
+                                 .projection = proj,
+                                 .viewPos = vec4(scene->camera.position.x, scene->camera.position.y,
+                                                 scene->camera.position.z, 1.0) };
+  GPU_EncodeBindShaderData(enc, 0, Binding_Camera_GetLayout(&camera_data));
+
+  TerrainUniforms uniforms = { .tex_slot_1 = storage->texture };
+  ShaderDataLayout terrain_data = TerrainUniforms_GetLayout(&uniforms);
+  GPU_EncodeBindShaderData(enc, 1, terrain_data);
+
+  GPU_EncodeSetVertexBuffer(enc, storage->vertex_buffer);
+  GPU_EncodeSetIndexBuffer(enc, storage->index_buffer);
+
+  GPU_EncodeDrawIndexedTris(enc, storage->indices_count);
+  // glDrawArrays(GL_POINTS, 0, storage->num_vertices);
+}
+
+f32 Heightmap_HeightXZ(const Heightmap* hmap, u32 x, u32 z) {
+  // its single channel so only one byte per pixel
+  size_t position = x * hmap->pixel_dimensions.x + z;
+  u8* bytes = hmap->image_data;
+  u8 channel = bytes[position];
+  float value = (float)channel / 2.0;  /// 255.0;
+  return value;
+}
+
+ShaderDataLayout TerrainUniforms_GetLayout(void* data) {
+  TerrainUniforms* d = data;
+  bool has_data = data != NULL;
+
+  ShaderBinding b1 = {
+    .label = "TextureSlot1",
+    .kind = BINDING_TEXTURE,
+    .vis = VISIBILITY_FRAGMENT,
+  };
+
+  if (has_data) {
+    b1.data.texture.handle = d->tex_slot_1;
+  }
+  return (ShaderDataLayout){ .bindings = { b1 }, .binding_count = 1 };
+}