/*
RENDER.C

symbols in this file:
001743B0 0020:
	_render_effects (0000)
001743D0 0010:
	_render_initialize (0000)
001743E0 0010:
	_render_initialize_for_new_map (0000)
001743F0 0010:
	_render_dispose_from_old_map (0000)
00174400 0010:
	_render_dispose (0000)
00174410 0110:
	_render_nonplayer_frame (0000)
00174520 00f0:
	_render_frame_pregame (0000)
00174610 0020:
	_render_frame_present (0000)
00174630 0070:
	_render_location_visible (0000)
001746A0 0050:
	_rendered_cluster_get (0000)
001746F0 03f0:
	_render_window (0000)
00174AE0 03f0:
	_render_player_frame (0000)
00174ED0 00f0:
	_render_frame (0000)
0029F44C 001f:
	??_C@_0BP@JNDFGHKA@c?3?2halo?2SOURCE?2render?2render?4c?$AA@ (0000)
0029F470 0061:
	??_C@_0GB@NHJDHKGO@location?9?$DOcluster_index?$DO?$DN0?5?$CG?$CG?5lo@ (0000)
0029F4D8 0052:
	??_C@_0FC@DLFICDJP@rendered_cluster_index?$DO?$DN0?5?$CG?$CG?5ren@ (0000)
0029F530 0052:
	??_C@_0FC@NBMIPGBN@window?9?$DOrender_camera?4viewport_b@ (0000)
0029F588 0051:
	??_C@_0FB@IDPOBHAJ@window?9?$DOrender_camera?4viewport_b@ (0000)
0029F5DC 002c:
	??_C@_0CM@LKHLGDKF@window?9?$DOrender_camera?4viewport_b@ (0000)
0029F608 002c:
	??_C@_0CM@HBCHLAAA@window?9?$DOrender_camera?4viewport_b@ (0000)
0029F638 006d:
	??_C@_0GN@PKELCNNH@?$CBmemcmp?$CI?$CGwindow?9?$DOrender_camera?4w@ (0000)
0029F6A8 0071:
	??_C@_0HB@BCLIBPGM@?$CBmemcmp?$CI?$CGwindow?9?$DOrender_camera?4v@ (0000)
0029F720 0048:
	??_C@_0EI@NGOLLMDP@?$CD?$CD?$CD?5ERROR?5something?5is?5wrong?5wit@ (0000)
0030D4D2 0004:
	_render_contrails_enabled (0000)
	_render_particles_enabled (0001)
	_render_particle_systems_enabled (0002)
	_render_weather_particle_systems_enabled (0003)
004B8B22 0001:
	_render_invalid_fog_warning_displayed (0000)
*/

/* ---------- headers */

#include "cseries.h"
#include "render.h"
#include "render_cameras_internal.h"
#include "render_particles.h"
#include "objects.h"
#include "scenario.h"
#include "structure_bsp_definitions.h"
#include "structures/structure_visibility.h"
#include "rasterizer.h"
#include "rasterizer/rasterizer_lights.h"
#include "profile.h"
#include "progress_bar.h"
#include "ui_widget.h"
#include "bink_playback.h"
#include "game.h"
#include "game_engine.h"
#include "interface/first_person_weapons.h"
#include "editor_stubs.h"
#include "render_debug.h"
#include "objects/object_lights_rendering.h"
#include "effects/particle_systems.h"
#include "effects/weather_particle_systems.h"
#ifdef HALO_ANDROID
#include "cutscene/cinematics.h"
#include "game/players.h"
#include "game/player_control.h"
#include "interface/hud.h"
#include "physics/collisions.h"
#include "units/units.h"
#include "halo_vr.h"
#endif

/* ---------- constants */

enum
{
	_render_target_primary = 0,
	_render_target_secondary,
};

enum
{
	_decal_layer_primary = 0,
	_decal_layer_secondary,
	_decal_layer_light,
	_decal_layer_alpha_tested,
	_decal_layer_water,
};

enum
{
	_render_planar_fog_mode_fully_fogged = 2,
};

/* ---------- macros */

#ifdef HALO_LINUX
#define RASTERIZER_TARGET_RENDER_PRIMARY_WIDTH halo_screen_width()
#else
#define RASTERIZER_TARGET_RENDER_PRIMARY_WIDTH 640
#endif
#define RASTERIZER_TARGET_RENDER_PRIMARY_HEIGHT 480

/* ---------- structures */

/* ---------- prototypes */

static void render_nonplayer_frame(
	const struct render_window *window,
	long window_type);
static void render_window(
	short local_player_index,
	const struct render_camera *camera,
	const struct render_frustum *frustum,
	const struct render_camera *rasterizer_camera,
	const struct render_frustum *rasterizer_frustum,
	short rasterizer_target,
	boolean has_mirror);
static void render_player_frame(
	struct render_window *window,
	const point2d *screenshot_combined_index);
#ifdef HALO_ANDROID
static void render_vr_player_frame(
	struct render_window *window);
static void render_vr_overlay(
	const struct render_window *window);
static void render_vr_laser(
	short local_player_index);
static void render_vr_scope(
	struct render_window *window);
#endif

void structure_get_planar_fog(
	short cluster_index,
	struct render_fog *fog);
void player_effect_get_screen_flash(
	short local_player_index,
	struct render_screen_flash *screen_flash);
void build_sprite_prepare_for_window(
	void);
void render_sky(
	void);
void render_objects(
	void);
void render_object_shadows(
	void);
void rasterizer_transparent_geometry_stop(
	void);
void interface_draw_fullscreen_overlays(
	void);
void rasterizer_debug_draw(
	void);
void render_debug(
	void);
void progress_bar_eachframe(
	void);
short main_get_window_count(
	void);

/* ---------- globals */

struct render_globals render;

static boolean render_invalid_fog_warning_displayed;

extern short global_screenshot_count;
extern short global_screenshot_size;

boolean render_contrails_enabled = TRUE;
boolean render_particles_enabled = TRUE;
boolean render_particle_systems_enabled = TRUE;
boolean render_weather_particle_systems_enabled = TRUE;

#ifdef HALO_ANDROID
/* VR (render_vr_player_frame): drawing an eye, which leaves out the HUD and
the menus, and that eye's frustum bounds */
static boolean render_vr_eye_pass = FALSE;
static const real_rectangle2d *render_vr_frustum_bounds = NULL;
#endif

/* ---------- public code */

void render_effects(
	boolean enable)
{
	render_weather_particle_systems_enabled = enable;
	render_particle_systems_enabled = enable;
	render_particles_enabled = enable;
	render_contrails_enabled = enable;
}

void render_initialize(
	void)
{
	render_objects_initialize();
}

void render_initialize_for_new_map(
	void)
{
	render_objects_initialize_for_new_map();
}

void render_dispose_from_old_map(
	void)
{
	render_objects_dispose_from_old_map();
}

void render_dispose(
	void)
{
	render_objects_dispose();
}

static void render_nonplayer_frame(
	const struct render_window *window,
	long window_type)
{
	struct rasterizer_window_begin_parameters parameters;

	profile_render_window_start(FALSE);
	memset(&parameters, 0, sizeof(parameters));

	render.camera = window->render_camera;
	render_camera_build_frustum(&render.camera, NULL, &render.frustum, TRUE);

	parameters.camera = window->rasterizer_camera;
	render_camera_build_frustum(&parameters.camera, NULL, &parameters.frustum, TRUE);

	parameters.rasterizer_target = _render_target_primary;
	parameters.suppress_clear = window_type == 0;
	parameters.window_index = NONE;
	rasterizer_window_begin(&parameters);

	switch (window_type)
	{
	case 0:
		/* letterbox bars and split screen dividers: laid out from the
		viewport, so not centered like the menus on a wide screen */
		interface_draw_fullscreen_overlays();
		rasterizer_debug_draw();
		break;

	case 1:
#ifdef HALO_LINUX
		halo_screen_ui_offset(TRUE);
		game_engine_nonplayer_post_rasterize();
		halo_screen_ui_offset(FALSE);
#else
		game_engine_nonplayer_post_rasterize();
#endif
		break;

	default:
		match_assert("c:\\halo\\SOURCE\\render\\render.c", 287, !"unreachable");
		break;
	}

	rasterizer_window_end();
	profile_render_window_end();

	return;
}

void render_frame_pregame(
	struct render_window const *window,
	struct bitmap_data *bitmap)
{
	struct rasterizer_frame_begin_parameters parameters;
	struct rasterizer_window_begin_parameters rasterizer_parameters;

	render.frame_index++;

	rasterizer_frame_begin(&parameters);
	rasterizer_windows_begin();
	profile_render_window_start(FALSE);

	memset(&rasterizer_parameters, 0, sizeof(rasterizer_parameters));

	render.camera = window->render_camera;
	render_camera_build_frustum(&render.camera, NULL, &render.frustum, TRUE);

	rasterizer_parameters.camera = window->rasterizer_camera;
	render_camera_build_frustum(&rasterizer_parameters.camera, NULL, &rasterizer_parameters.frustum, TRUE);

	rasterizer_parameters.rasterizer_target = 0;
	rasterizer_window_begin(&rasterizer_parameters);

#ifdef HALO_LINUX
	halo_screen_ui_offset(TRUE);
	render_ui_widgets(0, &window->rasterizer_camera.viewport_bounds);
	halo_screen_ui_offset(FALSE);
#else
	render_ui_widgets(0, &window->rasterizer_camera.viewport_bounds);
#endif
	bink_playback_render();

	{
		real progress;
		if (game_map_loading_in_progress(&progress))
		{
			progress_bar_display(progress);
		}
	}

	rasterizer_window_end();
	profile_render_window_end();
	rasterizer_windows_end();
	rasterizer_frame_end();

	return;
}

void render_frame_present(
	const point2d *screenshot_index,
	struct bitmap_data *bitmap)
{
	rasterizer_present(bitmap, screenshot_index);

	return;
}

boolean render_location_visible(
	struct location *location)
{
	match_assert("c:\\halo\\SOURCE\\render\\render.c", 584, location->cluster_index>=0 && location->cluster_index<global_structure_bsp_get()->clusters.count);
	return TEST_FLAG(render.visible_cluster_flags[location->cluster_index>>5], location->cluster_index&31);
}

struct rendered_cluster *rendered_cluster_get(
	short rendered_cluster_index)
{
	match_assert("c:\\halo\\SOURCE\\render\\render.c", 592, rendered_cluster_index>=0 && rendered_cluster_index<render.rendered_cluster_count);
	return &render.rendered_clusters[rendered_cluster_index];
}

static void render_window(
	short local_player_index,
	const struct render_camera *camera,
	const struct render_frustum *frustum,
	const struct render_camera *rasterizer_camera,
	const struct render_frustum *rasterizer_frustum,
	short rasterizer_target,
	boolean has_mirror)
{
	struct rasterizer_window_begin_parameters parameters;
	short rendered_cluster_index;

	profile_render_window_start(TRUE);
	render.scene_index++;
	memset(&parameters, 0, sizeof(parameters));

	render.local_player_index = local_player_index;
	render.camera = *camera;
	render.frustum = *frustum;
	parameters.camera = *rasterizer_camera;
	parameters.frustum = *rasterizer_frustum;
	parameters.rasterizer_target = rasterizer_target;
	parameters.has_mirror = has_mirror;
	parameters.window_index = render.window_index;
	parameters.fog = render.fog;

	structure_visibility_compute();
	player_effect_get_screen_flash(local_player_index, &parameters.screen_flash);
	rasterizer_window_begin(&parameters);

	if (!bink_playback_in_progress())
	{
		build_sprite_prepare_for_window();
#ifdef HALO_ANDROID
		halo_vr_multiview_sky(TRUE);
#endif
		render_sky();
#ifdef HALO_ANDROID
		halo_vr_multiview_sky(FALSE);
#endif
		first_person_weapon_render_update();
		lights_preprocess_scene();
		render_objects();
		structure_render_preprocess();
		structure_render_lightmaps();
		rasterizer_lens_flares_submit_occlusion_tests();
		render_object_shadows();
		lights_render_diffuse();

		rasterizer_decals_begin(_decal_layer_light);
		for (rendered_cluster_index = 0;
			rendered_cluster_index < render.rendered_cluster_count;
			rendered_cluster_index++)
		{
			rasterizer_decals_draw(rendered_cluster_get(rendered_cluster_index)->cluster_index);
		}
		rasterizer_decals_end();

		rasterizer_decals_begin(_decal_layer_alpha_tested);
		for (rendered_cluster_index = 0;
			rendered_cluster_index < render.rendered_cluster_count;
			rendered_cluster_index++)
		{
			rasterizer_decals_draw(rendered_cluster_get(rendered_cluster_index)->cluster_index);
		}
		rasterizer_decals_end();

		structure_render_diffuse_texture();

		rasterizer_decals_begin(_decal_layer_primary);
		for (rendered_cluster_index = 0;
			rendered_cluster_index < render.rendered_cluster_count;
			rendered_cluster_index++)
		{
			rasterizer_decals_draw(rendered_cluster_get(rendered_cluster_index)->cluster_index);
		}
		rasterizer_decals_end();

		rasterizer_decals_begin(_decal_layer_secondary);
		for (rendered_cluster_index = 0;
			rendered_cluster_index < render.rendered_cluster_count;
			rendered_cluster_index++)
		{
			rasterizer_decals_draw(rendered_cluster_get(rendered_cluster_index)->cluster_index);
		}
		rasterizer_decals_end();

		lights_render_specular();
		structure_render_specular_lightmaps();
		structure_render_reflection_lightmap_masks();
		structure_render_reflection_mirrors();
		structure_render_reflections();
		structure_render_transparent_geometry();
		structure_render_fog();
		game_engine_post_rasterize_objects();
		weather_particle_systems_render();
		render_particles();
		particle_systems_render();
		render_contrails_normal();
		rasterizer_transparent_geometry_draw(TRUE);

		rasterizer_decals_begin(_decal_layer_water);
		for (rendered_cluster_index = 0;
			rendered_cluster_index < render.rendered_cluster_count;
			rendered_cluster_index++)
		{
			rasterizer_decals_draw(rendered_cluster_get(rendered_cluster_index)->cluster_index);
		}
		rasterizer_decals_end();

		structure_render_detail_objects();
		rasterizer_transparent_geometry_draw(FALSE);
		rasterizer_transparent_geometry_stop();
		structure_render_fog_screen();
		rasterizer_lens_flares_draw();
#ifdef HALO_ANDROID
		if (render_vr_eye_pass)
		{
			/* the HUD and the menus go on the overlay (render_vr_overlay) */
			rasterizer_screen_flash();
		}
		else
#endif
		{
			interface_draw_screen();
			rasterizer_screen_flash();
#ifdef HALO_LINUX
			halo_screen_ui_offset(TRUE);
			render_ui_widgets(local_player_index, &rasterizer_camera->viewport_bounds);
			halo_screen_ui_offset(FALSE);
#else
			render_ui_widgets(local_player_index, &rasterizer_camera->viewport_bounds);
#endif
		}
	}

	bink_playback_render();
#ifdef HALO_ANDROID
	if (render_vr_eye_pass)
		render_vr_laser(local_player_index);
#endif
	render_camera_debug_frustum(&render.camera, &render.frustum);
	render_debug();
	editor_render();
	rasterizer_debug_draw();
	rasterizer_window_end();
	profile_render_window_end();

	return;
}

static void render_player_frame(
	struct render_window *window,
	const point2d *screenshot_combined_index)
{
	struct render_camera *camera;
	boolean has_mirror;
	real_rectangle2d frustum_bounds;
	struct render_frustum frustum;
	struct render_frustum rasterizer_frustum;
	struct render_mirror mirror;

	camera = &window->render_camera;
	has_mirror = FALSE;

	structure_visibility_find_camera(camera);
	render.fog.runtime_flags = 0;
	scenario_get_atmospheric_fog(
		window->local_player_index,
		(word)render.visible_sky_index,
		&camera->position,
		&render.fog);
	structure_get_planar_fog((short)render.cluster_index, &render.fog);

	if (render.fog.atmospheric_maximum_distance != 0.0f &&
		render.visible_sky_index == NONE &&
		render.fog.planar_maximum_distance > render.fog.atmospheric_maximum_distance)
	{
		render.fog.planar_maximum_distance = render.fog.atmospheric_maximum_distance;
	}

	if (render.fog.atmospheric_maximum_density == 1.0f &&
		render.fog.atmospheric_maximum_distance != 0.0f)
	{
		window->render_camera.z_far = MIN(
			window->render_camera.z_far,
			render.fog.atmospheric_maximum_distance);
	}

	if (render.fog.planar_mode == _render_planar_fog_mode_fully_fogged &&
		render.fog.planar_maximum_distance != 0.0f)
	{
		window->render_camera.z_far = MIN(
			window->render_camera.z_far,
			render.fog.planar_maximum_distance);
	}

	if (window->render_camera.z_far <= window->render_camera.z_near)
	{
		if (!render_invalid_fog_warning_displayed)
		{
			error(2, "### ERROR something is wrong with the fog in the sky tag or the fog tag");
			render_invalid_fog_warning_displayed = TRUE;
		}

		window->render_camera.z_far = window->render_camera.z_near + 0.01f;
	}

	match_assert(
		"c:\\halo\\SOURCE\\render\\render.c",
		187,
		!memcmp(&window->render_camera.viewport_bounds,
			&window->rasterizer_camera.viewport_bounds,
			sizeof(rectangle2d)));
	match_assert(
		"c:\\halo\\SOURCE\\render\\render.c",
		188,
		!memcmp(&window->render_camera.window_bounds,
			&window->rasterizer_camera.window_bounds,
			sizeof(rectangle2d)));

	render_camera_build_frustum_bounds(camera, &frustum_bounds);
#ifdef HALO_ANDROID
	if (render_vr_frustum_bounds)
		frustum_bounds = *render_vr_frustum_bounds;
#endif

	if (screenshot_combined_index != NULL)
	{
		long tile_count;

		tile_count = global_screenshot_count * global_screenshot_size;
		if (tile_count > 0)
		{
			real tile_width;
			real tile_height;
			real_rectangle2d adjusted_bounds;

			tile_width = (frustum_bounds.x1 - frustum_bounds.x0) / (real)tile_count;
			tile_height = (frustum_bounds.y1 - frustum_bounds.y0) / (real)tile_count;
			adjusted_bounds.x0 =
				(real)screenshot_combined_index->x * tile_width + frustum_bounds.x0;
			adjusted_bounds.y0 =
				(real)(tile_count - screenshot_combined_index->y - 1) * tile_height + frustum_bounds.y0;
			adjusted_bounds.x1 = adjusted_bounds.x0 + tile_width;
			adjusted_bounds.y1 = adjusted_bounds.y0 + tile_height;
			frustum_bounds = adjusted_bounds;
		}
	}

	render_camera_build_frustum(camera, &frustum_bounds, &frustum, TRUE);
	render_camera_build_frustum(
		&window->rasterizer_camera,
		&frustum_bounds,
		&rasterizer_frustum,
		TRUE);

	if (main_get_window_count() == 1)
	{
		if (structure_visibility_find_mirror(camera, &frustum, &mirror))
		{
			short saved_cluster_index;
			struct render_camera mirror_camera;
			struct render_frustum mirror_frustum;

			saved_cluster_index = (short)render.cluster_index;
			match_assert("c:\\halo\\SOURCE\\render\\render.c", 225, window->render_camera.viewport_bounds.x0==0);
			match_assert("c:\\halo\\SOURCE\\render\\render.c", 226, window->render_camera.viewport_bounds.y0==0);
			match_assert("c:\\halo\\SOURCE\\render\\render.c", 227, window->render_camera.viewport_bounds.x1==RASTERIZER_TARGET_RENDER_PRIMARY_WIDTH);
			match_assert("c:\\halo\\SOURCE\\render\\render.c", 228, window->render_camera.viewport_bounds.y1==RASTERIZER_TARGET_RENDER_PRIMARY_HEIGHT);

			render_camera_mirror(camera, &mirror, &mirror_camera);
			render_camera_build_frustum(
				&mirror_camera,
				&frustum_bounds,
				&mirror_frustum,
				TRUE);

			rasterizer_profile_enable(FALSE);
			render.cluster_index = mirror.cluster_index;
			render_window(
				NONE,
				&mirror_camera,
				&mirror_frustum,
				&mirror_camera,
				&mirror_frustum,
				_render_target_secondary,
				FALSE);
			render.cluster_index = saved_cluster_index;
			rasterizer_profile_enable(TRUE);
			has_mirror = TRUE;
		}
	}

	render_window(
		window->local_player_index,
		camera,
		&frustum,
		&window->rasterizer_camera,
		&rasterizer_frustum,
		_render_target_primary,
		has_mirror);

	return;
}

#ifdef HALO_ANDROID
static void render_vr_camera_set(
	struct render_camera *camera,
	const float position[3],
	const float forward[3],
	const float up[3],
	real vertical_field_of_view)
{
	camera->position.x = position[0];
	camera->position.y = position[1];
	camera->position.z = position[2];
	camera->forward.i = forward[0];
	camera->forward.j = forward[1];
	camera->forward.k = forward[2];
	camera->up.i = up[0];
	camera->up.j = up[1];
	camera->up.k = up[2];
	camera->vertical_field_of_view = vertical_field_of_view;
}

/* A player's view in VR (port/linux/include/halo_vr.h): drawn once per eye
from the headset's eye poses, placed at the game's camera, each copied to
its eye image; then the HUD and the menus, over nothing, for the overlay
the headset shows in front of the eyes. */
static void render_vr_player_frame(
	struct render_window *window)
{
	float game_position[3];
	short eye;

	game_position[0] = window->render_camera.position.x;
	game_position[1] = window->render_camera.position.y;
	game_position[2] = window->render_camera.position.z;
	{
		/* seated, the vehicle's heading as this frame draws it (between
		ticks): the view turns with it smoothly */
		long player_index = local_player_get_player_index(window->local_player_index);
		long unit_index = player_index == NONE ? NONE : player_get(player_index)->unit_index;
		long vehicle_index = unit_index == NONE ? NONE : object_get(unit_index)->object.parent_object_index;
		real_matrix4x3 *nodes = vehicle_index == NONE ? NULL : render_interpolation_object_node_matrices(vehicle_index);

		if (nodes)
			halo_vr_set_seat_frame(window->local_player_index, (float)atan2(nodes[0].forward.j, nodes[0].forward.i));
	}
	if (halo_vr_multiview())
	{
		/* both eyes at once, from between them */
		struct render_window eye_window = *window;
		float position[3], forward[3], up[3], bounds[4];
		float vertical_field_of_view;
		real_rectangle2d frustum_bounds;

		halo_vr_center_camera(game_position, position, forward, up, &vertical_field_of_view, bounds);
		render_vr_camera_set(&eye_window.render_camera, position, forward, up, vertical_field_of_view);
		render_vr_camera_set(&eye_window.rasterizer_camera, position, forward, up, vertical_field_of_view);
		frustum_bounds.x0 = bounds[0];
		frustum_bounds.x1 = bounds[1];
		frustum_bounds.y0 = bounds[2];
		frustum_bounds.y1 = bounds[3];
		{
			/* the depth of what the game projects itself (its sprites) */
			struct render_frustum frustum;

			render_camera_build_frustum(&eye_window.rasterizer_camera, &frustum_bounds, &frustum, TRUE);
			halo_vr_multiview_projection(frustum.projection_matrix[2][2], frustum.projection_matrix[3][2]);
		}
		render_vr_eye_pass = TRUE;
		render_vr_frustum_bounds = &frustum_bounds;
		render_player_frame(&eye_window, NULL);
		render_vr_frustum_bounds = NULL;
		render_vr_eye_pass = FALSE;
		halo_vr_capture_multiview();
	}
	else for (eye = 0; eye < 2; eye++)
	{
		struct render_window eye_window = *window;
		float position[3], forward[3], up[3], bounds[4];
		float vertical_field_of_view;
		real_rectangle2d frustum_bounds;

		halo_vr_eye_camera(eye, game_position, position, forward, up, &vertical_field_of_view, bounds);
		render_vr_camera_set(&eye_window.render_camera, position, forward, up, vertical_field_of_view);
		render_vr_camera_set(&eye_window.rasterizer_camera, position, forward, up, vertical_field_of_view);
		frustum_bounds.x0 = bounds[0];
		frustum_bounds.x1 = bounds[1];
		frustum_bounds.y0 = bounds[2];
		frustum_bounds.y1 = bounds[3];

		render_vr_eye_pass = TRUE;
		render_vr_frustum_bounds = &frustum_bounds;
		render_player_frame(&eye_window, NULL);
		render_vr_frustum_bounds = NULL;
		render_vr_eye_pass = FALSE;
		halo_vr_capture_eye(eye);
	}
	render_vr_scope(window);
	render_vr_overlay(window);

	return;
}

/* The scope's view (halo_vr_scope): zoomed in, the player's view once more,
from the weapon along its aim through the zoom's field of view, into a
small square at the back buffer's top left (a sixteenth of it: the disc
is a few centimetres across), which becomes the disc over the weapon. */
#define RENDER_VR_SCOPE_SIZE 120

static void render_vr_scope(
	struct render_window *window)
{
	short zoom_level = player_control_get_zoom_level(window->local_player_index);
	long player_index = local_player_get_player_index(window->local_player_index);
	float position[3], forward[3], up[3];
	float vertical_field_of_view;
	real magnification;
	struct render_window scope_window;

	if (zoom_level == NONE || player_index == NONE || player_get(player_index)->unit_index == NONE)
		return;
	magnification = unit_get_zoom_magnification(player_get(player_index)->unit_index, zoom_level);
	if (!halo_vr_scope(window->local_player_index, magnification, position, forward, up, &vertical_field_of_view))
		return;
	scope_window = *window;
	render_vr_camera_set(&scope_window.render_camera, position, forward, up, vertical_field_of_view);
	render_vr_camera_set(&scope_window.rasterizer_camera, position, forward, up, vertical_field_of_view);
	scope_window.render_camera.viewport_bounds.x0 = scope_window.render_camera.viewport_bounds.y0 = 0;
	scope_window.render_camera.viewport_bounds.x1 = scope_window.render_camera.viewport_bounds.y1 = RENDER_VR_SCOPE_SIZE;
	scope_window.render_camera.window_bounds = scope_window.render_camera.viewport_bounds;
	scope_window.rasterizer_camera.viewport_bounds = scope_window.render_camera.viewport_bounds;
	scope_window.rasterizer_camera.window_bounds = scope_window.render_camera.viewport_bounds;

	render_vr_eye_pass = TRUE;
	render_player_frame(&scope_window, NULL);
	render_vr_eye_pass = FALSE;
	halo_vr_capture_scope(0.f, 0.f, (float)RENDER_VR_SCOPE_SIZE / RASTERIZER_TARGET_RENDER_PRIMARY_WIDTH,
		(float)RENDER_VR_SCOPE_SIZE / RASTERIZER_TARGET_RENDER_PRIMARY_HEIGHT);

	return;
}

/* where a ray from the weapon, as far as the longest-ranged weapons reach,
hits something, or its end */
static void render_vr_ray_end(
	float const start[3],
	float const direction[3],
	long unit_index,
	real_point3d *origin,
	real_point3d *end)
{
	real_vector3d ray;
	struct collision_result collision;

	origin->x = start[0];
	origin->y = start[1];
	origin->z = start[2];
	ray.i = direction[0] * 100.f;
	ray.j = direction[1] * 100.f;
	ray.k = direction[2] * 100.f;
	if (collision_test_vector(_collision_test_for_projectiles_flags, origin, &ray, unit_index, &collision))
		*end = collision.point;
	else
		point_from_line3d(origin, &ray, 1.f, end);
}

/* how far the weapon in the right hand aims before it hits something (the
crosshair floats there, halo_vr_set_aim_distance), and its laser up to
there, along the barrel as a reload turns it (halo_vr_laser), if vr.laser
is on, but not over the menus */
static void render_vr_laser(
	short local_player_index)
{
	static real_argb_color const laser_color = { 1.f, 1.f, 0.15f, 0.1f };
	float start[3], direction[3];
	real_point3d origin, end;
	long player_index;
	long unit_index = NONE;

	player_index = local_player_get_player_index(local_player_index);
	if (player_index != NONE)
		unit_index = player_get(player_index)->unit_index;
	if (!halo_vr_ready_laser(local_player_index, start, direction))
		return;
	/* seated, the aim passes through the player's own vehicle (a gun's
	barrel and shield are in front of the hand) */
	if (unit_index != NONE && object_get(unit_index)->object.parent_object_index != NONE)
		unit_index = object_get(unit_index)->object.parent_object_index;
	render_vr_ray_end(start, direction, unit_index, &origin, &end);
	halo_vr_set_aim_distance(distance3d(&origin, &end));

	if (!halo_vr_laser(local_player_index, start, direction) || ui_widgets_menus_active())
		return;
	render_vr_ray_end(start, direction, unit_index, &origin, &end);
	render_debug_line(TRUE, &origin, &end, &laser_color);
	render_debug_point(TRUE, &end, 0.02f, &laser_color);

	return;
}

/* the HUD and the menus of a player's view, on the cleared back buffer */
static void render_vr_overlay(
	const struct render_window *window)
{
	struct rasterizer_window_begin_parameters parameters;
	boolean menus_active = ui_widgets_menus_active();

	halo_vr_begin_overlay(menus_active);
	profile_render_window_start(FALSE);
	memset(&parameters, 0, sizeof(parameters));
	render.local_player_index = window->local_player_index;
	render.camera = window->render_camera;
	render_camera_build_frustum(&render.camera, NULL, &render.frustum, TRUE);
	parameters.camera = window->rasterizer_camera;
	render_camera_build_frustum(&parameters.camera, NULL, &parameters.frustum, TRUE);
	parameters.rasterizer_target = _render_target_primary;
	parameters.suppress_clear = TRUE;
	parameters.window_index = render.window_index;

	if (!menus_active && halo_vr_crosshair_apart())
	{
		/* the weapon's crosshair alone, taken to where the weapon aims */
		rasterizer_window_begin(&parameters);
		hud_draw_crosshair();
		rasterizer_window_end();
		halo_vr_capture_crosshair();
	}
	rasterizer_window_begin(&parameters);

	interface_draw_screen();
	halo_screen_ui_offset(TRUE);
	render_ui_widgets(window->local_player_index, &window->rasterizer_camera.viewport_bounds);
	halo_screen_ui_offset(FALSE);

	rasterizer_window_end();
	profile_render_window_end();

	return;
}

#endif
void render_frame(
	struct render_window *windoze,
	short window_count,
	const point2d *screenshot_page_index,
	const point2d *screenshot_index,
	struct bitmap_data *screenshot_bitmap,
	real time_delta_since_tick_sec)
{
	struct rasterizer_frame_begin_parameters parameters;
	short window_index;
	struct render_window *window;
	point2d screenshot_combined_index;

	render.frame_index++;
	render.time_delta_since_tick_sec = time_delta_since_tick_sec;
	memset(&parameters, 0, sizeof(parameters));
#ifdef HALO_LINUX
	/* continuous between ticks (render_interpolation.c) */
	parameters.game_time_sec = render_interpolation_game_time_sec(game_time_get());
#else
	parameters.game_time_sec = (real)game_time_get() * (1.0f / TICKS_PER_SECOND);
#endif
	rasterizer_frame_begin(&parameters);
	rasterizer_windows_begin();

	for (window_index = 0; window_index < window_count; window_index++)
	{
		long window_type;

		window = &windoze[window_index];
		render.window_index = window_index;
		if (window->console_window)
		{
			window_type = 0;
		}
#ifdef HALO_ANDROID
		else if (window->local_player_index != NONE && screenshot_index == NULL &&
			halo_vr_stereo_player(window->local_player_index, cinematic_in_progress()))
		{
			render_vr_player_frame(window);
			continue;
		}
#endif
		else if (window->local_player_index != NONE)
		{
			if (screenshot_index != NULL && screenshot_page_index != NULL)
			{
				screenshot_combined_index.x =
					screenshot_page_index->x * global_screenshot_size + screenshot_index->x;
				screenshot_combined_index.y =
					screenshot_page_index->y * global_screenshot_size + screenshot_index->y;
			}

			render_player_frame(
				window,
				screenshot_index != NULL ? &screenshot_combined_index : NULL);
			continue;
		}
		else
		{
			window_type = 1;
		}

		render_nonplayer_frame(window, window_type);
	}

#ifdef HALO_LINUX
	halo_screen_ui_offset(TRUE);
	progress_bar_eachframe();
	halo_screen_ui_offset(FALSE);
#else
	progress_bar_eachframe();
#endif
	rasterizer_windows_end();
	rasterizer_frame_end();

	return;
}

/* ---------- private code */