4 files changed, 269 insertions, 18 deletions

diff --git a/src/renderer/imm_renderer.c b/src/renderer/imm_renderer.c
new file mode 100644
index 0000000..01cc5bb
--- /dev/null
+++ b/src/renderer/imm_renderer.c
@@ -0,0 +1,192 @@
+#include "imm_renderer_impl.h"
+
+#include <gfx/core.h>
+#include <gfx/llr/llr.h>
+#include <gfx/renderer/imm_renderer.h>
+#include <gfx/util/shader.h>
+
+#include <math/aabb3.h>
+
+#include <assert.h>
+#include <string.h> // memcpy
+
+bool gfx_imm_make(ImmRenderer* renderer, GfxCore* gfxcore, LLR* llr) {
+  assert(renderer);
+  assert(gfxcore);
+  assert(llr);
+
+  const size_t num_triangle_verts = GFX_IMM_MAX_NUM_TRIANGLES * 3;
+
+  renderer->gfxcore = gfxcore;
+  renderer->llr     = llr;
+
+  renderer->triangles = gfx_make_geometry(
+      gfxcore,
+      &(GeometryDesc){.type         = Triangles,
+                      .buffer_usage = BufferDynamic,
+                      .num_verts    = num_triangle_verts,
+                      .positions3d  = (BufferView3d){
+                           .size_bytes = num_triangle_verts * sizeof(vec3)}});
+  if (!renderer->triangles) {
+    goto cleanup;
+  }
+
+  renderer->shader = gfx_make_immediate_mode_shader(gfxcore);
+  if (!renderer->shader) {
+    goto cleanup;
+  }
+
+  gfx_imm_set_colour(renderer, vec4_make(0.0f, 0.0f, 0.0f, 1.0f));
+
+  return true;
+
+cleanup:
+  gfx_imm_destroy(renderer);
+  return false;
+}
+
+void gfx_imm_destroy(ImmRenderer* renderer) {
+  assert(renderer);
+  assert(renderer->gfxcore);
+
+  if (renderer->triangles) {
+    gfx_destroy_geometry(renderer->gfxcore, &renderer->triangles);
+    // TODO: Could also destroy the geometry's buffers here.
+  }
+
+  if (renderer->shader) {
+    gfx_destroy_shader_program(renderer->gfxcore, &renderer->shader);
+  }
+}
+
+void gfx_imm_flush(ImmRenderer* renderer) {
+  assert(renderer);
+
+  if (renderer->num_triangle_verts > 0) {
+    gfx_update_geometry(
+        renderer->triangles,
+        &(GeometryDesc){
+            .num_verts   = renderer->num_triangle_verts,
+            .positions3d = (BufferView3d){
+                                          .data       = renderer->triangle_verts,
+                                          .size_bytes = renderer->num_triangle_verts * sizeof(vec3)}
+    });
+
+    gfx_llr_render_geometry(renderer->llr, renderer->triangles);
+
+    renderer->num_triangle_verts = 0;
+  }
+}
+
+void gfx_imm_start(ImmRenderer* renderer) {
+  assert(renderer);
+
+  // Shader uniforms are applied lazily.
+  // TODO: In the event that gfx_activate_shader_program() activates uniforms
+  //  automatically for convenience, call an overload here that doesn't do so.
+  // gfx_activate_shader_program(renderer->shader);
+  gfx_llr_set_shader(renderer->llr, renderer->shader);
+}
+
+void gfx_imm_end(ImmRenderer* renderer) {
+  assert(renderer);
+
+  gfx_imm_flush(renderer);
+  // gfx_deactivate_shader_program(renderer->shader);
+  gfx_llr_set_shader(renderer->llr, 0);
+}
+
+void gfx_imm_draw_triangles(
+    ImmRenderer* renderer, const vec3 verts[], size_t num_triangles) {
+  assert(renderer);
+  assert(verts);
+  const size_t new_verts = num_triangles * 3;
+  assert(
+      renderer->num_triangle_verts + new_verts <
+      (GFX_IMM_MAX_NUM_TRIANGLES * 3));
+
+  memcpy(
+      renderer->triangle_verts + renderer->num_triangle_verts, verts,
+      new_verts * sizeof(vec3));
+
+  renderer->num_triangle_verts += new_verts;
+}
+
+void gfx_imm_draw_triangle(ImmRenderer* renderer, const vec3 verts[3]) {
+  gfx_imm_draw_triangles(renderer, verts, 1);
+}
+
+void gfx_imm_draw_aabb2(ImmRenderer* renderer, aabb2 box) {
+  assert(renderer);
+
+  // clang-format off
+  const vec3 verts[4] = {
+      vec3_make(box.min.x, box.min.y, 0),    // 3 ---- 2
+      vec3_make(box.max.x, box.min.y, 0),    // |      |
+      vec3_make(box.max.x, box.max.y, 0),    // |      |
+      vec3_make(box.min.x, box.max.y, 0)};   // 0 ---- 1
+  // clang-format on
+
+#define tri(i0, i1, i2) verts[i0], verts[i1], verts[i2]
+  const vec3 tris[6] = {tri(0, 1, 2), tri(0, 2, 3)};
+#undef tri
+
+  gfx_imm_draw_triangles(renderer, tris, 2);
+}
+
+void gfx_imm_draw_aabb3(ImmRenderer* renderer, aabb3 box) {
+  assert(renderer);
+
+  // clang-format off
+  const vec3 vertices[8] = {
+      vec3_make(box.min.x, box.min.y, box.max.z), //     7 ----- 6
+      vec3_make(box.max.x, box.min.y, box.max.z), //    /       /|
+      vec3_make(box.max.x, box.max.y, box.max.z), //   3 ----- 2 |
+      vec3_make(box.min.x, box.max.y, box.max.z), //   |       | |
+      vec3_make(box.min.x, box.min.y, box.min.z), //   | 4 ----- 5
+      vec3_make(box.max.x, box.min.y, box.min.z), //   |/      |/
+      vec3_make(box.max.x, box.max.y, box.min.z), //   0 ----- 1
+      vec3_make(box.min.x, box.max.y, box.min.z)};
+  // clang-format on
+
+  gfx_imm_draw_box3(renderer, vertices);
+}
+
+void gfx_imm_draw_box3(ImmRenderer* renderer, const vec3 vertices[8]) {
+  assert(renderer);
+  assert(vertices);
+
+  //     7 ----- 6
+  //    /       /|
+  //   3 ----- 2 |
+  //   |       | |
+  //   | 4 ----- 5
+  //   |/      |/
+  //   0 ----- 1
+
+#define tri(i0, i1, i2) vertices[i0], vertices[i1], vertices[i2]
+  const vec3 tris[36] = {
+      // Front.
+      tri(0, 1, 2), tri(0, 2, 3),
+      // Right.
+      tri(1, 5, 6), tri(1, 6, 2),
+      // Back.
+      tri(5, 4, 7), tri(5, 7, 6),
+      // Left.
+      tri(4, 0, 03), tri(4, 3, 7),
+      // Top.
+      tri(3, 2, 6), tri(3, 6, 7),
+      // Bottom.
+      tri(0, 4, 5), tri(0, 5, 1)};
+
+  gfx_imm_draw_triangles(renderer, tris, 12);
+}
+
+void gfx_imm_set_colour(ImmRenderer* renderer, vec4 colour) {
+  assert(renderer);
+  assert(renderer->shader);
+
+  gfx_imm_flush(renderer);
+
+  gfx_set_vec4_uniform(renderer->shader, "Colour", colour);
+}
diff --git a/src/renderer/imm_renderer_impl.h b/src/renderer/imm_renderer_impl.h
new file mode 100644
index 0000000..61b49a7
--- /dev/null
+++ b/src/renderer/imm_renderer_impl.h
@@ -0,0 +1,43 @@
+#pragma once
+
+#include <gfx/sizes.h>
+
+#include <math/vec3.h>
+
+#include <stdbool.h>
+#include <stddef.h>
+
+typedef struct Geometry      Geometry;
+typedef struct GfxCore       GfxCore;
+typedef struct IBL           IBL;
+typedef struct LLR           LLR;
+typedef struct Material      Material;
+typedef struct ShaderProgram ShaderProgram;
+typedef struct Texture       Texture;
+
+/// Immediate mode renderer.
+///
+/// Currently, the immediate mode renderer can only draw up to a maximum number
+/// of primitives per frame. It does not adjust this number dynamically. Keeps
+/// things simple while the extra complexity is not needed.
+/// TODO: Flush the buffer when it reaches its maximum size to remove this
+///  constraint.
+typedef struct ImmRenderer {
+  GfxCore* gfxcore;
+  LLR*     llr;
+
+  ShaderProgram* shader; // Immediate-mode shader program for primitives.
+  Geometry*      triangles;
+  size_t         num_triangle_verts; // Number of triangle verts this frame.
+  // TODO: wireframe rendering.
+  struct {
+    bool wireframe : 1;
+  } flags;
+  vec3 triangle_verts[GFX_IMM_MAX_NUM_TRIANGLES * 3];
+} ImmRenderer;
+
+/// Create a new immediate mode renderer.
+bool gfx_imm_make(ImmRenderer*, GfxCore*, LLR*);
+
+/// Destroy the immediate mode renderer.
+void gfx_imm_destroy(ImmRenderer*);
diff --git a/src/renderer/renderer.c b/src/renderer/renderer.c
index c2a7dda..0c1fe78 100644
--- a/src/renderer/renderer.c
+++ b/src/renderer/renderer.c
@@ -1,10 +1,10 @@
 #include "renderer_impl.h"
 
+#include "llr/light_impl.h"
+#include "llr/material_impl.h"
+#include "llr/mesh_impl.h"
 #include "scene/animation_impl.h"
 #include "scene/camera_impl.h"
-#include "scene/light_impl.h"
-#include "scene/material_impl.h"
-#include "scene/mesh_impl.h"
 #include "scene/model_impl.h"
 #include "scene/node_impl.h"
 #include "scene/object_impl.h"
@@ -12,16 +12,18 @@
 #include "scene/scene_memory.h"
 
 #include <gfx/core.h>
+#include <gfx/llr/llr.h>
 #include <gfx/util/ibl.h>
 #include <gfx/util/shader.h>
 
-#include <log/log.h>
+// #include <log/log.h>
+#include "gfx/gfx.h"
+
 #include <math/mat4.h>
 #include <math/spatial3.h>
 
 #include <assert.h>
 
-// TODO: Move to a header like "constants.h".
 static const int IRRADIANCE_MAP_WIDTH               = 1024;
 static const int IRRADIANCE_MAP_HEIGHT              = 1024;
 static const int PREFILTERED_ENVIRONMENT_MAP_WIDTH  = 128;
@@ -29,16 +31,18 @@ static const int PREFILTERED_ENVIRONMENT_MAP_HEIGHT = 128;
 static const int BRDF_INTEGRATION_MAP_WIDTH         = 512;
 static const int BRDF_INTEGRATION_MAP_HEIGHT        = 512;
 
-bool renderer_make(Renderer* renderer, GfxCore* gfxcore) {
+bool gfx_renderer_make(Renderer* renderer, LLR* llr, GfxCore* gfxcore) {
   assert(renderer);
+  assert(llr);
   assert(gfxcore);
 
   renderer->gfxcore = gfxcore;
+  renderer->llr     = llr;
 
   return true;
 }
 
-void renderer_destroy(Renderer* renderer) {
+void gfx_renderer_destroy(Renderer* renderer) {
   if (!renderer) {
     return;
   }
@@ -117,9 +121,9 @@ static ShaderProgram* load_shader(Renderer* renderer, RenderSceneMode mode) {
 //   }
 // }
 
-/// Computes irradiance and prefiltered environment maps for the light if they
+/// Compute irradiance and prefiltered environment maps for the light if they
 /// have not been already computed.
-static bool setup_environment_light(
+static bool set_up_environment_light(
     Renderer* renderer, GfxCore* gfxcore, EnvironmentLight* light) {
   assert(renderer);
   assert(light);
@@ -168,6 +172,7 @@ cleanup:
 
 typedef struct RenderState {
   GfxCore*       gfxcore;
+  LLR*           llr;
   Renderer*      renderer;
   ShaderProgram* shader; // Null to use scene shaders.
   const Scene*   scene;
@@ -209,6 +214,7 @@ static void draw_recursively(
 
   // Anima.
   if (node->type == AnimaNode) {
+    // Save the anima so that we can animate objects.
     state->anima = gfx_get_node_anima(node);
   }
   // Activate light.
@@ -217,7 +223,7 @@ static void draw_recursively(
     assert(light);
 
     if (light->type == EnvironmentLightType) {
-      bool result = setup_environment_light(
+      bool result = set_up_environment_light(
           state->renderer, state->gfxcore, &light->environment);
       // TODO: Handle the result in a better way.
       assert(result);
@@ -238,11 +244,13 @@ static void draw_recursively(
     // TODO: Here we would frustum-cull the object.
 
     // TODO: Avoid computing matrices like Modelview or MVP if the shader does
-    // not use them.
+    //  not use them.
     const mat4 model_matrix = node_transform;
     const mat4 modelview    = mat4_mul(*state->view_matrix, model_matrix);
     const mat4 mvp          = mat4_mul(*state->projection, modelview);
 
+    // A model/anima can have many skeletons. We need to animate the given
+    // object using its skeleton, not just any skeleton of the anima.
     if (object->skeleton.val) {
       load_skeleton(state, object->skeleton);
     }
@@ -260,9 +268,11 @@ static void draw_recursively(
       assert(mesh->material);
 
       // TODO: Here we would frustum-cull the mesh. The AABB would have to be
-      // transformed by the model matrix. Rotation would make the AABB
-      // relatively large, but still, the culling would be conservative.
+      //  transformed by the model matrix. Rotation would make the AABB
+      //  relatively large, but still, the culling would be conservative.
 
+      // TODO: Make sure we strictly set only the uniforms that are required by
+      //  mesh rendering. See the other item below.
       // Apply common shader uniforms not captured by materials.
       ShaderProgram* shader = state->shader ? state->shader : mesh->shader;
       gfx_set_mat4_uniform(shader, "ModelMatrix", &model_matrix);
@@ -270,7 +280,10 @@ static void draw_recursively(
       gfx_set_mat4_uniform(shader, "View", state->view_matrix);
       gfx_set_mat4_uniform(shader, "Projection", state->projection);
       gfx_set_mat4_uniform(shader, "MVP", &mvp);
+      // TODO: CameraRotation is only used by the skyquad and cubemap_filtering
+      //  shaders, not mesh rendering.
       gfx_set_mat4_uniform(shader, "CameraRotation", state->camera_rotation);
+      // TODO: Fovy and Aspect are only used by the skyquad, not necessary here.
       gfx_set_float_uniform(shader, "Fovy", state->fovy);
       gfx_set_float_uniform(shader, "Aspect", state->aspect);
       if (state->camera) {
@@ -297,9 +310,9 @@ static void draw_recursively(
             shader, "PrefilteredEnvironmentMap",
             light->prefiltered_environment_map);
         gfx_set_float_uniform(
-            shader, "MaxReflectionLOD", light->max_reflection_lod);
+            shader, "MaxReflectionLOD", (float)light->max_reflection_lod);
       }
-      material_activate(shader, mesh->material);
+      gfx_material_activate(shader, mesh->material);
       gfx_activate_shader_program(shader);
       gfx_apply_uniforms(shader);
       gfx_render_geometry(mesh->geometry);
@@ -327,7 +340,7 @@ void gfx_render_scene(Renderer* renderer, const RenderSceneParams* params) {
   const Scene*       scene  = params->scene;
   const SceneCamera* camera = params->camera;
 
-  GfxCore* gfxcore = renderer->gfxcore;
+  GfxCore* const gfxcore = renderer->gfxcore;
 
   mat4 projection, camera_rotation, view_matrix;
   if (camera) {
@@ -347,6 +360,7 @@ void gfx_render_scene(Renderer* renderer, const RenderSceneParams* params) {
 
   RenderState state = {
       .gfxcore           = gfxcore,
+      .llr               = renderer->llr,
       .renderer          = renderer,
       .shader            = shader,
       .scene             = scene,
diff --git a/src/renderer/renderer_impl.h b/src/renderer/renderer_impl.h
index fc14dcb..6fd0c15 100644
--- a/src/renderer/renderer_impl.h
+++ b/src/renderer/renderer_impl.h
@@ -5,11 +5,13 @@
 #include <stdbool.h>
 
 typedef struct IBL           IBL;
+typedef struct LLR           LLR;
 typedef struct ShaderProgram ShaderProgram;
 typedef struct Texture       Texture;
 
 typedef struct Renderer {
   GfxCore* gfxcore;
+  LLR*     llr;
   IBL*     ibl;
   Texture* brdf_integration_map;
   struct {
@@ -21,7 +23,7 @@ typedef struct Renderer {
 } Renderer;
 
 /// Create a new renderer.
-bool renderer_make(Renderer*, GfxCore*);
+bool gfx_renderer_make(Renderer*, LLR*, GfxCore*);
 
 /// Destroy the renderer.
-void renderer_destroy(Renderer*);
+void gfx_renderer_destroy(Renderer*);