Commit b403da22 authored by Jakob Bornecrantz's avatar Jakob Bornecrantz Committed by Jakob Bornecrantz

aux/util: Add distortion mesh generation

parent b67d65b4
......@@ -49,6 +49,8 @@ set(UTIL_SOURCE_FILES
util/u_debug.h
util/u_device.c
util/u_device.h
util/u_distortion_mesh.c
util/u_distortion_mesh.h
util/u_documentation.h
util/u_format.c
util/u_format.h
......
......@@ -12,6 +12,8 @@ lib_aux_util = static_library(
'util/u_debug.h',
'util/u_device.c',
'util/u_device.h',
'util/u_distortion_mesh.c',
'util/u_distortion_mesh.h',
'util/u_documentation.h',
'util/u_format.c',
'util/u_format.h',
......
// Copyright 2019, Collabora, Ltd.
// SPDX-License-Identifier: BSL-1.0
/*!
* @file
* @brief @ref xrt_frame helpers.
* @author Jakob Bornecrantz <jakob@collabora.com>
* @ingroup aux_util
*/
#include "util/u_misc.h"
#include "util/u_frame.h"
#include "util/u_debug.h"
#include "util/u_format.h"
#include "util/u_distortion_mesh.h"
#include "math/m_vec2.h"
#include <stdio.h>
#include <assert.h>
DEBUG_GET_ONCE_NUM_OPTION(mesh_size, "XRT_MESH_SIZE", 64)
/*
*
* Func running helpers.
*
*/
static int
index_for(int row, int col, int stride, int offset)
{
return row * stride + col + offset;
}
void
run_func(u_distortion_mesh_func func,
void *user_ptr,
int num_views,
struct xrt_hmd_parts *target,
size_t num)
{
assert(num_views == 2);
assert(num_views <= 2);
size_t offset_vertices[2] = {0};
size_t offset_indices[2] = {0};
int cells_cols = num;
int cells_rows = num;
int vert_cols = cells_cols + 1;
int vert_rows = cells_rows + 1;
size_t num_vertices_per_view = vert_rows * vert_cols;
size_t num_vertices = num_vertices_per_view * num_views;
size_t stride_in_floats = 8;
size_t num_floats = num_vertices * stride_in_floats;
float *verts = U_TYPED_ARRAY_CALLOC(float, num_floats);
// Setup the vertices for all views.
size_t i = 0;
for (int view = 0; view < num_views; view++) {
offset_vertices[view] = i / stride_in_floats;
for (int r = 0; r < vert_rows; r++) {
// This goes from 0 to 1.0 inclusive.
float v = (float)r / (float)cells_rows;
for (int c = 0; c < vert_cols; c++) {
// This goes from 0 to 1.0 inclusive.
float u = (float)c / (float)cells_cols;
func(view, u, v, &verts[i], user_ptr);
i += stride_in_floats;
}
}
}
size_t num_indices_per_view = cells_rows * (vert_cols * 2 + 2);
size_t num_indices = num_indices_per_view * num_views;
int *indices = U_TYPED_ARRAY_CALLOC(int, num_indices);
// Set up indices for all views.
i = 0;
for (int view = 0; view < num_views; view++) {
offset_indices[view] = i;
size_t off = offset_vertices[view];
for (int r = 0; r < cells_rows; r++) {
// Top vertex row for this cell row, left most vertex.
indices[i++] = index_for(r, 0, vert_cols, off);
for (int c = 0; c < vert_cols; c++) {
indices[i++] = index_for(r, c, vert_cols, off);
indices[i++] =
index_for(r + 1, c, vert_cols, off);
}
// Bottom vertex row for this cell row, right most
// vertex.
indices[i++] =
index_for(r + 1, vert_cols - 1, vert_cols, off);
}
}
target->distortion.models = XRT_DISTORTION_MODEL_MESHUV;
target->distortion.preferred = XRT_DISTORTION_MODEL_MESHUV;
target->distortion.mesh.vertices = verts;
target->distortion.mesh.stride = stride_in_floats * sizeof(float);
target->distortion.mesh.num_vertices = num_vertices;
target->distortion.mesh.num_uv_channels = 3;
target->distortion.mesh.indices = indices;
target->distortion.mesh.num_indices[0] = num_indices_per_view;
target->distortion.mesh.num_indices[1] = num_indices_per_view;
target->distortion.mesh.offset_indices[0] = offset_indices[0];
target->distortion.mesh.offset_indices[1] = offset_indices[1];
target->distortion.mesh.total_num_indices = num_indices;
}
void
u_distortion_mesh_from_func(u_distortion_mesh_func func,
void *user_ptr,
int num_views,
struct xrt_hmd_parts *target)
{
size_t num = debug_get_num_option_mesh_size();
run_func(func, user_ptr, num_views, target, num);
}
/*
*
* Panotools.
*
*/
#define mul m_vec2_mul
#define mul_scalar m_vec2_mul_scalar
#define add m_vec2_add
#define sub m_vec2_sub
#define div m_vec2_div
#define div_scalar m_vec2_div_scalar
#define len m_vec2_len
struct panotools_state
{
const struct u_panotools_values *vals[2];
};
static void
panotools_func(int view, float u, float v, float result[8], void *user_ptr)
{
struct panotools_state *state = (struct panotools_state *)user_ptr;
const struct u_panotools_values val = *state->vals[view];
// Make the position in the range of [-1, 1]
result[0] = u * 2.0 - 1.0;
result[1] = v * 2.0 - 1.0;
struct xrt_vec2 r = {u, v};
r = mul(r, val.viewport_size);
r = sub(r, val.lens_center);
r = div_scalar(r, val.scale);
float r_mag = len(r);
r_mag = val.distortion_k[0] + // r^1
val.distortion_k[1] * r_mag + // r^2
val.distortion_k[2] * r_mag * r_mag + // r^3
val.distortion_k[3] * r_mag * r_mag * r_mag + // r^4
val.distortion_k[4] * r_mag * r_mag * r_mag * r_mag; // r^5
struct xrt_vec2 r_dist = mul_scalar(r, r_mag);
r_dist = mul_scalar(r_dist, val.scale);
struct xrt_vec2 r_uv = mul_scalar(r_dist, val.aberration_k[0]);
r_uv = add(r_uv, val.lens_center);
r_uv = div(r_uv, val.viewport_size);
struct xrt_vec2 g_uv = mul_scalar(r_dist, val.aberration_k[1]);
g_uv = add(g_uv, val.lens_center);
g_uv = div(g_uv, val.viewport_size);
struct xrt_vec2 b_uv = mul_scalar(r_dist, val.aberration_k[2]);
b_uv = add(b_uv, val.lens_center);
b_uv = div(b_uv, val.viewport_size);
result[2] = r_uv.x;
result[3] = r_uv.y;
result[4] = g_uv.x;
result[5] = g_uv.y;
result[6] = b_uv.x;
result[7] = b_uv.y;
}
void
u_distortion_mesh_from_panotools(const struct u_panotools_values *left,
const struct u_panotools_values *right,
struct xrt_hmd_parts *target)
{
struct panotools_state state;
state.vals[0] = left;
state.vals[1] = right;
size_t num = debug_get_num_option_mesh_size();
run_func(panotools_func, &state, 2, target, num);
}
/*
*
* No distortion.
*
*/
static void
no_distortion_func(int view, float u, float v, float result[8], void *user_ptr)
{
result[0] = u * 2.0 - 1.0;
result[1] = v * 2.0 - 1.0;
result[2] = u;
result[3] = v;
result[4] = u;
result[5] = v;
result[6] = u;
result[7] = v;
}
void
u_distortion_mesh_none(struct xrt_hmd_parts *target)
{
run_func(no_distortion_func, NULL, 2, target, 8);
}
// Copyright 2019, Collabora, Ltd.
// SPDX-License-Identifier: BSL-1.0
/*!
* @file
* @brief Code to generate disortion meshes.
* @author Jakob Bornecrantz <jakob@collabora.com>
* @ingroup aux_util
*/
#pragma once
#include "xrt/xrt_device.h"
#include "xrt/xrt_defines.h"
#ifdef __cplusplus
extern "C" {
#endif
/*!
* Values to create a distortion mesh from panotools values.
*
* @ingroup aux_util
*/
struct u_panotools_values
{
//! Panotools universal distortion k (reverse order from OpenHMD).
float distortion_k[5];
//! Panotools post distortion scale, <r, g, b>.
float aberration_k[3];
//! Panotools warp scale.
float scale;
//! Center of the lens.
struct xrt_vec2 lens_center;
//! Viewport size.
struct xrt_vec2 viewport_size;
};
/*!
* Callback used when generating a distortion mesh.
*
* @ingroup aux_util
*/
typedef void (*u_distortion_mesh_func)(
int view, float x, float y, float result[8], void *user_ptr);
/*!
* Given a callback and a user_ptr generates num_views meshes.
*
* @ingroup aux_util
*/
void
u_distortion_mesh_from_func(u_distortion_mesh_func func,
void *user_ptr,
int num_views,
struct xrt_hmd_parts *target);
/*!
* Given two sets of panotools values creates the left and th right uv meshes.
*
* @ingroup aux_util
*/
void
u_distortion_mesh_from_panotools(const struct u_panotools_values *left,
const struct u_panotools_values *right,
struct xrt_hmd_parts *target);
/*!
* Create two distortion meshes with no distortion.
*
* @ingroup aux_util
*/
void
u_distortion_mesh_none(struct xrt_hmd_parts *target);
#ifdef __cplusplus
}
#endif
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