8 files changed, 664 insertions, 0 deletions

diff --git a/src/llr/light.c b/src/llr/light.c
new file mode 100644
index 0000000..0fa1522
--- /dev/null
+++ b/src/llr/light.c
@@ -0,0 +1,42 @@
+#include "light_impl.h"
+
+#include "memory.h"
+#include "scene/node_impl.h"
+
+#include <error.h>
+
+static void make_environment_light(
+    Light* light, const EnvironmentLightDesc* desc) {
+  assert(light);
+  assert(desc);
+  light->type                        = EnvironmentLightType;
+  light->environment.environment_map = desc->environment_map;
+}
+
+Light* gfx_make_light(const LightDesc* desc) {
+  assert(desc);
+
+  Light* light = mem_alloc_light();
+
+  switch (desc->type) {
+  case EnvironmentLightType:
+    make_environment_light(light, &desc->light.environment);
+    break;
+  default:
+    log_error("Unhandled light type");
+    gfx_destroy_light(&light);
+    return 0;
+  }
+
+  return light;
+}
+
+void gfx_destroy_light(Light** light) {
+  assert(light);
+  if (*light) {
+    if ((*light)->parent.val) {
+      gfx_del_node((*light)->parent);
+    }
+    mem_free_light(light);
+  }
+}
diff --git a/src/llr/light_impl.h b/src/llr/light_impl.h
new file mode 100644
index 0000000..5ec8145
--- /dev/null
+++ b/src/llr/light_impl.h
@@ -0,0 +1,25 @@
+#pragma once
+
+#include <gfx/llr/light.h>
+
+#include "scene/types.h"
+
+typedef struct Texture Texture;
+
+/// An environment light.
+typedef struct EnvironmentLight {
+  const Texture* environment_map;
+  const Texture* irradiance_map;              // Renderer implementation.
+  const Texture* prefiltered_environment_map; // Renderer implementation.
+  int max_reflection_lod; // Mandatory when prefiltered_environment_map is
+                          // given.
+} EnvironmentLight;
+
+/// A scene light.
+typedef struct Light {
+  LightType type;
+  union {
+    EnvironmentLight environment;
+  };
+  node_idx parent; // Parent SceneNode.
+} Light;
diff --git a/src/llr/llr.c b/src/llr/llr.c
new file mode 100644
index 0000000..fe02c0d
--- /dev/null
+++ b/src/llr/llr.c
@@ -0,0 +1,406 @@
+#include "light_impl.h"
+#include "llr_impl.h"
+#include "mesh_impl.h"
+
+#include "llr/material_impl.h"
+#include "scene/animation_impl.h"
+
+#include <gfx/core.h>
+#include <gfx/util/ibl.h>
+
+#include <cassert.h>
+
+static const int IRRADIANCE_MAP_WIDTH               = 1024;
+static const int IRRADIANCE_MAP_HEIGHT              = 1024;
+static const int PREFILTERED_ENVIRONMENT_MAP_WIDTH  = 128;
+static const int PREFILTERED_ENVIRONMENT_MAP_HEIGHT = 128;
+static const int BRDF_INTEGRATION_MAP_WIDTH         = 512;
+static const int BRDF_INTEGRATION_MAP_HEIGHT        = 512;
+
+/// Initialize renderer state for IBL.
+static bool init_ibl(LLR* renderer) {
+  assert(renderer);
+  assert(!renderer->ibl);
+  assert(!renderer->brdf_integration_map);
+
+  if (!((renderer->ibl = gfx_make_ibl(renderer->gfxcore)))) {
+    return false;
+  }
+
+  if (!((renderer->brdf_integration_map = gfx_make_brdf_integration_map(
+             renderer->ibl, renderer->gfxcore, BRDF_INTEGRATION_MAP_WIDTH,
+             BRDF_INTEGRATION_MAP_HEIGHT)))) {
+    return false;
+  }
+
+  return true;
+}
+
+/// Compute irradiance and prefiltered environment maps for the light if they
+/// have not been already computed.
+///
+/// This is done lazily here, and not when the light is created, because we
+/// need an IBL instance to do this and it is more convenient for the public
+/// API to create lights without worrying about those details. It also makes the
+/// public API cheaper, since the maps are only computed when they are actually
+/// needed.
+static bool set_up_environment_light(LLR* renderer, EnvironmentLight* light) {
+  assert(renderer);
+  assert(light);
+  assert(renderer->ibl);
+  assert(renderer->brdf_integration_map);
+
+  if (light->irradiance_map) {
+    assert(light->prefiltered_environment_map);
+    return true;
+  }
+
+  // For convenience.
+  GfxCore* gfxcore = renderer->gfxcore;
+
+  Texture* irradiance_map              = 0;
+  Texture* prefiltered_environment_map = 0;
+
+  if (!((irradiance_map = gfx_make_irradiance_map(
+             renderer->ibl, gfxcore, light->environment_map,
+             IRRADIANCE_MAP_WIDTH, IRRADIANCE_MAP_HEIGHT)))) {
+    goto cleanup;
+  }
+
+  int max_mip_level = 0;
+  if (!((prefiltered_environment_map = gfx_make_prefiltered_environment_map(
+             renderer->ibl, gfxcore, light->environment_map,
+             PREFILTERED_ENVIRONMENT_MAP_WIDTH,
+             PREFILTERED_ENVIRONMENT_MAP_HEIGHT, &max_mip_level)))) {
+    goto cleanup;
+  }
+
+  light->irradiance_map              = irradiance_map;
+  light->prefiltered_environment_map = prefiltered_environment_map;
+  light->max_reflection_lod          = max_mip_level;
+
+  return true;
+
+cleanup:
+  if (irradiance_map) {
+    gfx_destroy_texture(gfxcore, &irradiance_map);
+  }
+  if (prefiltered_environment_map) {
+    gfx_destroy_texture(gfxcore, &prefiltered_environment_map);
+  }
+  return false;
+}
+
+static void configure_light(LLR* renderer, Light* light) {
+  assert(renderer);
+  assert(light);
+
+  // For convenience.
+  ShaderProgram* const shader = renderer->shader;
+
+  switch (light->type) {
+  case EnvironmentLightType: {
+    EnvironmentLight* env = &light->environment;
+
+    const bool initialized = set_up_environment_light(renderer, env);
+    ASSERT(initialized);
+    assert(env->environment_map);
+    assert(env->irradiance_map);
+    assert(env->prefiltered_environment_map);
+    assert(renderer->brdf_integration_map);
+
+    gfx_set_texture_uniform(
+        shader, "BRDFIntegrationMap", renderer->brdf_integration_map);
+    gfx_set_texture_uniform(shader, "Sky", env->environment_map);
+    gfx_set_texture_uniform(shader, "IrradianceMap", env->irradiance_map);
+    gfx_set_texture_uniform(
+        shader, "PrefilteredEnvironmentMap", env->prefiltered_environment_map);
+    gfx_set_float_uniform(
+        shader, "MaxReflectionLOD", (float)env->max_reflection_lod);
+
+    break;
+  }
+  default:
+    assert(false); // TODO: Implement other light types.
+    break;
+  }
+}
+
+static void configure_state(LLR* renderer) {
+  assert(renderer);
+
+  // Check if anything changed first so that we don't call gfx_apply_uniforms()
+  // unnecessarily.
+  const bool nothing_changed = (renderer->changed_flags == 0);
+  if (nothing_changed) {
+    return;
+  }
+  // Setting a null shader is also allowed, in which case there is nothing to
+  // configure.
+  if (renderer->shader == 0) {
+    renderer->shader_changed = false;
+    return;
+  }
+
+  // For convenience.
+  ShaderProgram* const shader = renderer->shader;
+  const mat4* const    model = &renderer->matrix_stack[renderer->stack_pointer];
+
+  // TODO: Check to see which ones the shader actually uses and avoid
+  //  computing the unnecessary matrices.
+
+  if (renderer->matrix_changed || renderer->shader_changed) {
+    renderer->matrix_changed = false;
+
+    gfx_set_mat4_uniform(shader, "Model", model);
+    gfx_set_mat4_uniform(shader, "ModelMatrix", model);
+  }
+
+  // TODO: camera_changed is not set anywhere. Need to think how imm primitive
+  //  rendering and imm mesh rendering work together. We could treat imm
+  //  primitive calls like setting a new shader.
+  if (renderer->camera_changed || renderer->shader_changed) {
+    renderer->camera_changed = false;
+
+    // Set all supported camera-related uniforms. Shaders can choose which ones
+    // to use.
+    const mat4 modelview = mat4_mul(renderer->view, *model);
+    const mat4 view_proj = mat4_mul(renderer->projection, renderer->view);
+    const mat4 mvp       = mat4_mul(renderer->projection, modelview);
+
+    gfx_set_mat4_uniform(shader, "Modelview", &modelview);
+    gfx_set_mat4_uniform(shader, "View", &renderer->view);
+    gfx_set_mat4_uniform(shader, "Projection", &renderer->projection);
+    gfx_set_mat4_uniform(shader, "ViewProjection", &view_proj);
+    gfx_set_mat4_uniform(shader, "MVP", &mvp);
+    gfx_set_vec3_uniform(shader, "CameraPosition", renderer->camera_position);
+    gfx_set_mat4_uniform(shader, "CameraRotation", &renderer->camera_rotation);
+    gfx_set_float_uniform(shader, "Fovy", renderer->fovy);
+    gfx_set_float_uniform(shader, "Aspect", renderer->aspect);
+  }
+
+  if (renderer->lights_changed || renderer->shader_changed) {
+    renderer->lights_changed = false;
+
+    // TODO: Could do better by only setting the lights that have actually
+    //  changed.
+    // TODO: Will also need to pass the number of lights to the shader once the
+    //  other light types are implemented.
+    for (int i = 0; i < renderer->num_lights; ++i) {
+      configure_light(renderer, renderer->lights[i]);
+    }
+  }
+
+  if (renderer->skeleton_changed || renderer->shader_changed) {
+    renderer->skeleton_changed = false;
+
+    if (renderer->num_joints > 0) {
+      gfx_set_mat4_array_uniform(
+          shader, "JointMatrices", renderer->joint_matrices,
+          renderer->num_joints);
+    }
+  }
+
+  if (renderer->material_changed || renderer->shader_changed) {
+    renderer->material_changed = false;
+
+    gfx_material_activate(renderer->shader, renderer->material);
+  }
+
+  if (renderer->shader_changed) {
+    renderer->shader_changed = false;
+    gfx_activate_shader_program(renderer->shader);
+  }
+
+  // TODO: At present, this results in many redundant calls to
+  //  glGetUniformLocation() and glUniformXyz(). Look at the trace.
+  //
+  // TODO: Could add to qapitrace functionality to detect redundant calls and
+  //  other inefficiencies. Maybe ask in the Github first if there would be
+  //  interest in this.
+  //
+  // Must be called after activating the program.
+  gfx_apply_uniforms(renderer->shader);
+}
+
+bool gfx_llr_make(LLR* renderer, GfxCore* gfxcore) {
+  assert(renderer);
+  assert(gfxcore);
+
+  renderer->gfxcore = gfxcore;
+  if (!init_ibl(renderer)) {
+    goto cleanup;
+  }
+  gfx_llr_load_identity(renderer);
+  renderer->view            = mat4_id();
+  renderer->projection      = mat4_id();
+  renderer->camera_rotation = mat4_id();
+  return true;
+
+cleanup:
+  gfx_llr_destroy(renderer);
+  return false;
+}
+
+void gfx_llr_destroy(LLR* renderer) {
+  assert(renderer);
+  assert(renderer->gfxcore);
+
+  if (renderer->brdf_integration_map) {
+    gfx_destroy_texture(renderer->gfxcore, &renderer->brdf_integration_map);
+  }
+
+  // TODO: Do this once the IBL from the scene renderer is gone.
+  if (renderer->ibl) {
+    // gfx_destroy_ibl(renderer->gfxcore, &renderer->ibl);
+  }
+}
+
+void gfx_llr_set_shader(LLR* renderer, ShaderProgram* shader) {
+  assert(renderer);
+  // null shader is allowed, so do not assert it.
+
+  // It's important to not set shader_changed unnecessarily, since that would
+  // re-trigger the setting of uniforms.
+  if (renderer->shader != shader) {
+    renderer->shader         = shader;
+    renderer->shader_changed = true;
+  }
+}
+
+void gfx_llr_push_light(LLR* renderer, Light* light) {
+  assert(renderer);
+  assert(light);
+  assert(renderer->num_lights >= 0);
+  ASSERT(renderer->num_lights < GFX_LLR_MAX_NUM_LIGHTS);
+
+  renderer->lights[renderer->num_lights++] = light;
+  renderer->lights_changed                 = true;
+}
+
+void gfx_llr_pop_light(LLR* renderer) {
+  assert(renderer);
+  ASSERT(renderer->num_lights > 0);
+
+  renderer->lights[--renderer->num_lights] = 0;
+  renderer->lights_changed                 = true;
+}
+
+void gfx_llr_set_skeleton(
+    LLR* renderer, const Anima* anima, const Skeleton* skeleton) {
+  assert(renderer);
+  assert(anima);
+  assert(skeleton);
+  assert(skeleton->num_joints <= GFX_MAX_NUM_JOINTS);
+
+  for (size_t i = 0; i < skeleton->num_joints; ++i) {
+    const joint_idx joint_index = skeleton->joints[i];
+    const Joint*    joint       = &anima->joints[joint_index];
+    renderer->joint_matrices[i] = joint->joint_matrix;
+  }
+  renderer->num_joints       = skeleton->num_joints;
+  renderer->skeleton_changed = true;
+}
+
+void gfx_llr_clear_skeleton(LLR* renderer) {
+  assert(renderer);
+
+  renderer->num_joints       = 0;
+  renderer->skeleton_changed = true;
+}
+
+void gfx_llr_set_material(LLR* renderer, const Material* material) {
+  assert(renderer);
+  assert(material);
+
+  renderer->material         = material;
+  renderer->material_changed = true;
+}
+
+void gfx_llr_set_camera(LLR* renderer, const Camera* camera) {
+  assert(renderer);
+
+  renderer->camera_position = camera->spatial.p;
+  renderer->camera_rotation =
+      mat4_rotation(spatial3_transform(&camera->spatial));
+  renderer->view       = spatial3_inverse_transform(&camera->spatial);
+  renderer->projection = camera->projection;
+  // Assuming a perspective matrix.
+  renderer->fovy = (R)atan(1.0 / (mat4_at(camera->projection, 1, 1))) * 2;
+  renderer->camera_changed = true;
+}
+
+void gfx_llr_set_aspect(LLR* renderer, float aspect) {
+  assert(renderer);
+
+  renderer->aspect         = aspect;
+  renderer->camera_changed = true;
+}
+
+void gfx_llr_render_geometry(LLR* renderer, const Geometry* geometry) {
+  assert(renderer);
+  assert(geometry);
+
+  configure_state(renderer);
+  gfx_render_geometry(geometry);
+}
+
+void gfx_llr_render_mesh(LLR* renderer, const Mesh* mesh) {
+  assert(renderer);
+  assert(mesh);
+  assert(mesh->geometry);
+  assert(mesh->material);
+  assert(mesh->shader);
+
+  gfx_llr_set_material(renderer, mesh->material);
+  gfx_llr_set_shader(renderer, mesh->shader);
+  gfx_llr_render_geometry(renderer, mesh->geometry);
+}
+
+void gfx_llr_load_identity(LLR* renderer) {
+  assert(renderer);
+
+  renderer->matrix_stack[0] = mat4_id();
+  renderer->stack_pointer   = 0;
+  renderer->matrix_changed  = true;
+}
+
+void gfx_llr_push_matrix(LLR* renderer, const mat4* matrix) {
+  assert(renderer);
+  assert(matrix);
+  assert(renderer->stack_pointer >= 0);
+  ASSERT(renderer->stack_pointer < GFX_LLR_MAX_NUM_MATRICES);
+
+  renderer->stack_pointer += 1;
+  renderer->matrix_stack[renderer->stack_pointer] =
+      mat4_mul(*matrix, renderer->matrix_stack[renderer->stack_pointer - 1]);
+  renderer->matrix_changed = true;
+}
+
+void gfx_llr_pop_matrix(LLR* renderer) {
+  assert(renderer);
+  ASSERT(renderer->stack_pointer > 0);
+
+  // For debugging, zero out the matrix stack as matrices are popped out.
+  memset(
+      &renderer->matrix_stack[renderer->stack_pointer], 0,
+      sizeof(renderer->matrix_stack[0]));
+  renderer->stack_pointer -= 1;
+  renderer->matrix_changed = true;
+}
+
+void gfx_llr_translate(LLR* renderer, vec3 offset) {
+  assert(renderer);
+
+  const mat4 mat = mat4_translate(offset);
+  gfx_llr_push_matrix(renderer, &mat);
+}
+
+void gfx_llr_set_model_matrix(LLR* renderer, const mat4* model) {
+  assert(renderer);
+  assert(model);
+
+  renderer->matrix_stack[0] = *model;
+  renderer->stack_pointer   = 0;
+  renderer->matrix_changed  = true;
+}
diff --git a/src/llr/llr_impl.h b/src/llr/llr_impl.h
new file mode 100644
index 0000000..3f6a68f
--- /dev/null
+++ b/src/llr/llr_impl.h
@@ -0,0 +1,86 @@
+#pragma once
+
+#include <gfx/llr/llr.h>
+#include <gfx/sizes.h>
+
+#include <math/mat4.h>
+#include <math/vec3.h>
+
+#include <stdbool.h>
+#include <stddef.h>
+#include <stdint.h>
+
+typedef struct Geometry      Geometry;
+typedef struct GfxCore       GfxCore;
+typedef struct IBL           IBL;
+typedef struct Material      Material;
+typedef struct ShaderProgram ShaderProgram;
+typedef struct Texture       Texture;
+
+/// Immediate mode renderer.
+///
+/// The renderer caches state changes in memory and only programs the underlying
+/// shader program when a draw call is issued and if anything has changed. This
+/// keeps the number of graphics API calls to a minimum, but requires tracking
+/// state changes. The 'changed' booleans below fulfill this purpose, and
+/// indicate whether a given state has changed since the last draw call.
+///
+/// The renderer must combine state changes accordingly. For example, if only
+/// the lights have changed, then it is sufficient to update light uniforms in
+/// the current shader program. On the other hand, if the shader program has
+/// changed, then the renderer must reconfigure it from scratch and set light
+/// uniforms, camera uniforms, etc.
+///
+/// Note that the shader program API has its own level of caching as well, so
+/// reconfiguration at the level of the renderer does not result in the
+/// worst-case set of graphics API calls.
+typedef struct LLR {
+  GfxCore* gfxcore;
+
+  union {
+    struct {
+      bool shader_changed   : 1; // Whether the shader has changed.
+      bool camera_changed   : 1; // Whether the camera parameters have changed.
+      bool lights_changed   : 1; // Whether the lights have changed.
+      bool skeleton_changed : 1; // Whether the skeleton has changed.
+      bool material_changed : 1; // Whether the material has changed.
+      bool matrix_changed   : 1; // Whether the matrix stack has changed.
+    };
+    uint8_t changed_flags;
+  };
+
+  IBL*     ibl;
+  Texture* brdf_integration_map;
+
+  ShaderProgram* shader; // Active shader. Not owned.
+
+  const Material* material; // Active material. Not owned.
+
+  vec3 camera_position;
+  mat4 camera_rotation;
+  mat4 view;       // Camera view matrix.
+  mat4 projection; // Camera projection matrix.
+  R    fovy;       // Camera vertical field of view.
+  R    aspect;     // Aspect ratio.
+
+  // Lights are not const because environment lights store lazily-computed
+  // irradiance maps.
+  Light* lights[GFX_LLR_MAX_NUM_LIGHTS]; // Lights stack.
+  int    num_lights; // Number of lights enabled at a given point in time. It
+                     // points to one past the top of the stack.
+
+  size_t num_joints;
+  mat4   joint_matrices[GFX_MAX_NUM_JOINTS];
+
+  // The matrix stack contains pre-multiplied matrices.
+  // It is also never empty. The top of the stack is an identity matrix when the
+  // stack is "empty" from the user's perspective.
+  mat4 matrix_stack[GFX_LLR_MAX_NUM_MATRICES];
+  int  stack_pointer; // Points to the top of the stack.
+} LLR;
+
+/// Create a new immediate mode renderer.
+bool gfx_llr_make(LLR*, GfxCore*);
+
+/// Destroy the immediate mode renderer.
+void gfx_llr_destroy(LLR*);
diff --git a/src/llr/material.c b/src/llr/material.c
new file mode 100644
index 0000000..f09dd3f
--- /dev/null
+++ b/src/llr/material.c
@@ -0,0 +1,57 @@
+#include "material_impl.h"
+
+#include "memory.h"
+
+#include <gfx/core.h>
+
+static void material_make(Material* material, const MaterialDesc* desc) {
+  assert(material);
+  assert(desc);
+  assert(desc->num_uniforms < GFX_MAX_UNIFORMS_PER_MATERIAL);
+  material->num_uniforms = desc->num_uniforms;
+  for (int i = 0; i < desc->num_uniforms; ++i) {
+    material->uniforms[i] = desc->uniforms[i];
+  }
+}
+
+Material* gfx_make_material(const MaterialDesc* desc) {
+  assert(desc);
+  Material* material = mem_alloc_material();
+  material_make(material, desc);
+  return material;
+}
+
+void gfx_destroy_material(Material** material) { mem_free_material(material); }
+
+static void set_uniform(ShaderProgram* prog, const ShaderUniform* uniform) {
+  switch (uniform->type) {
+  case UniformTexture:
+    gfx_set_texture_uniform(prog, uniform->name.str, uniform->value.texture);
+    break;
+  case UniformMat4:
+    gfx_set_mat4_uniform(prog, uniform->name.str, &uniform->value.mat4);
+    break;
+  case UniformVec3:
+    gfx_set_vec3_uniform(prog, uniform->name.str, uniform->value.vec3);
+    break;
+  case UniformVec4:
+    gfx_set_vec4_uniform(prog, uniform->name.str, uniform->value.vec4);
+    break;
+  case UniformFloat:
+    gfx_set_float_uniform(prog, uniform->name.str, uniform->value.scalar);
+    break;
+  case UniformMat4Array:
+    gfx_set_mat4_array_uniform(
+        prog, uniform->name.str, uniform->value.array.values,
+        uniform->value.array.count);
+    break;
+  }
+}
+
+void gfx_material_activate(ShaderProgram* shader, const Material* material) {
+  assert(material);
+  for (int i = 0; i < material->num_uniforms; ++i) {
+    const ShaderUniform* uniform = &material->uniforms[i];
+    set_uniform(shader, uniform);
+  }
+}
diff --git a/src/llr/material_impl.h b/src/llr/material_impl.h
new file mode 100644
index 0000000..2b7cd89
--- /dev/null
+++ b/src/llr/material_impl.h
@@ -0,0 +1,15 @@
+#pragma once
+
+#include <gfx/llr/material.h>
+
+typedef struct ShaderProgram ShaderProgram;
+
+typedef struct Material {
+  ShaderUniform uniforms[GFX_MAX_UNIFORMS_PER_MATERIAL];
+  int           num_uniforms;
+} Material;
+
+/// Activate the material.
+///
+/// This configures the shader uniforms that are specific to the material.
+void gfx_material_activate(ShaderProgram* shader, const Material* material);
diff --git a/src/llr/mesh.c b/src/llr/mesh.c
new file mode 100644
index 0000000..5f9e5d0
--- /dev/null
+++ b/src/llr/mesh.c
@@ -0,0 +1,24 @@
+#include "mesh_impl.h"
+
+#include "memory.h"
+
+#include <assert.h>
+
+static void mesh_make(Mesh* mesh, const MeshDesc* desc) {
+  assert(mesh);
+  assert(desc);
+  assert(desc->geometry);
+  assert(desc->material);
+  assert(desc->shader);
+  mesh->geometry = desc->geometry;
+  mesh->material = desc->material;
+  mesh->shader   = desc->shader;
+}
+
+Mesh* gfx_make_mesh(const MeshDesc* desc) {
+  Mesh* mesh = mem_alloc_mesh();
+  mesh_make(mesh, desc);
+  return mesh;
+}
+
+void gfx_destroy_mesh(Mesh** mesh) { mem_free_mesh(mesh); }
diff --git a/src/llr/mesh_impl.h b/src/llr/mesh_impl.h
new file mode 100644
index 0000000..96e60df
--- /dev/null
+++ b/src/llr/mesh_impl.h
@@ -0,0 +1,9 @@
+#pragma once
+
+#include <gfx/llr/mesh.h>
+
+typedef struct Mesh {
+  const Geometry* geometry;
+  const Material* material;
+  ShaderProgram*  shader;
+} Mesh;