twn_draw: draw_camera_unproject()
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veclavtalica
parent
733a1786ab
commit
923cd81571
@ -100,6 +100,20 @@ TWN_API void draw_camera(Vec3 position, /* optional, default: (0, 0, 0)
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float zoom, /* optional, default: 1 */
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float draw_distance); /* optional, default: 100 */
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/* find position and looking direction of a 2d point into 3d space */
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/* make sure it's called with matching parameters to last draw_camera(), if you need them to match */
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typedef struct DrawCameraUnprojectResult {
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Vec3 position;
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Vec3 direction;
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} DrawCameraUnprojectResult;
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TWN_API DrawCameraUnprojectResult draw_camera_unproject(Vec2 point,
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Vec3 position,
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Vec3 direction,
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Vec3 up,
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float fov,
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float zoom,
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float draw_distance);
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/* same as draw_camera(), but with first person controller in mind */
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/* direction and up vectors are inferred from roll, pitch and yaw parameters (in radians) */
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/* return value is direction and up vectors, so that you can use them in logic (such as controllers) */
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@ -5,6 +5,7 @@
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#include "twn_types.h"
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#include "twn_util.h"
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#include "twn_vec.h"
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#include "twn_vec_c.h"
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#include "twn_deferred_commands.h"
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#include <SDL2/SDL.h>
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@ -497,6 +498,69 @@ DrawCameraFromPrincipalAxesResult draw_camera_from_principal_axes(Vec3 position,
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}
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DrawCameraUnprojectResult draw_camera_unproject(Vec2 point,
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Vec3 position,
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Vec3 direction,
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Vec3 up,
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float fov,
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float zoom,
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float draw_distance)
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{
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bool const orthographic = fabsf(0.0f - fov) < 0.00001f;
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if (!orthographic && fov >= (float)(M_PI))
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log_warn("Invalid fov given (%f)", (double)fov);
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/* inital zoom = 1.0 correlates to perspective from this */
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zoom *= 0.1f;
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float const aspect = (float)ctx.base_render_width / (float)ctx.base_render_height;
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Camera const camera = {
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.fov = fov,
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.pos = position,
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.target = vec3_norm(direction),
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.up = up,
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.viewbox = {
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aspect/-zoom, aspect/zoom,
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1/zoom, 1/-zoom
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},
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.far_z = draw_distance
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};
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Matrix4 const projection_matrix = orthographic ? camera_orthographic(&camera) : camera_perspective(&camera);
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Matrix4 const look_at_matrix = camera_look_at(&camera);
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/* TODO: cache matrices for repeated camera inputs, those are expensive */
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Matrix4 const inverse_view_proj = matrix_inverse(matrix_multiply(projection_matrix, look_at_matrix));
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point.y = (float)ctx.base_render_height - point.y;
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if (!orthographic) {
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point = (Vec2) {
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point.x,
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point.y,
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};
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}
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Vec4 v;
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v.x = 2.0f * point.x / (float)ctx.base_render_width - 1.0f;
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v.y = 2.0f * point.y / (float)ctx.base_render_height - 1.0f;
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v.z = 2.0f * 1.0f - 1.0f;
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v.w = 1.0f;
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log_vec2(point, "point");
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v = matrix_vector_multiply(inverse_view_proj, v);
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/* TODO: is it even ever not equal to 1 in our case ? */
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v = vec4_scale(v, 1.0f / v.w);
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return (DrawCameraUnprojectResult){
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.position = (Vec3){ v.x, v.y, v.z },
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.direction = vec3_norm(vec3_sub(position, (Vec3){ v.x, v.y, v.z })),
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};
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}
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void set_depth_range(double low, double high) {
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depth_range_low = low;
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depth_range_high = high;
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98
src/twn_vec_c.h
Normal file
98
src/twn_vec_c.h
Normal file
@ -0,0 +1,98 @@
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#ifndef TWN_VEC_C_H
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#define TWN_VEC_C_H
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#include "twn_types_c.h"
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#include <stdint.h>
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static inline Vec4 vec4_scale(Vec4 a, float s) {
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return (Vec4) { a.x * s, a.y * s, a.z * s, a.w * s };
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}
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static inline Matrix4 matrix_multiply(Matrix4 a, Matrix4 b) {
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Matrix4 dest;
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float const
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a00 = a.row[0].x, a01 = a.row[0].y, a02 = a.row[0].z, a03 = a.row[0].w,
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a10 = a.row[1].x, a11 = a.row[1].y, a12 = a.row[1].z, a13 = a.row[1].w,
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a20 = a.row[2].x, a21 = a.row[2].y, a22 = a.row[2].z, a23 = a.row[2].w,
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a30 = a.row[3].x, a31 = a.row[3].y, a32 = a.row[3].z, a33 = a.row[3].w,
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b00 = b.row[0].x, b01 = b.row[0].y, b02 = b.row[0].z, b03 = b.row[0].w,
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b10 = b.row[1].x, b11 = b.row[1].y, b12 = b.row[1].z, b13 = b.row[1].w,
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b20 = b.row[2].x, b21 = b.row[2].y, b22 = b.row[2].z, b23 = b.row[2].w,
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b30 = b.row[3].x, b31 = b.row[3].y, b32 = b.row[3].z, b33 = b.row[3].w;
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dest.row[0].x = a00 * b00 + a10 * b01 + a20 * b02 + a30 * b03;
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dest.row[0].y = a01 * b00 + a11 * b01 + a21 * b02 + a31 * b03;
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dest.row[0].z = a02 * b00 + a12 * b01 + a22 * b02 + a32 * b03;
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dest.row[0].w = a03 * b00 + a13 * b01 + a23 * b02 + a33 * b03;
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dest.row[1].x = a00 * b10 + a10 * b11 + a20 * b12 + a30 * b13;
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dest.row[1].y = a01 * b10 + a11 * b11 + a21 * b12 + a31 * b13;
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dest.row[1].z = a02 * b10 + a12 * b11 + a22 * b12 + a32 * b13;
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dest.row[1].w = a03 * b10 + a13 * b11 + a23 * b12 + a33 * b13;
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dest.row[2].x = a00 * b20 + a10 * b21 + a20 * b22 + a30 * b23;
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dest.row[2].y = a01 * b20 + a11 * b21 + a21 * b22 + a31 * b23;
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dest.row[2].z = a02 * b20 + a12 * b21 + a22 * b22 + a32 * b23;
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dest.row[2].w = a03 * b20 + a13 * b21 + a23 * b22 + a33 * b23;
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dest.row[3].x = a00 * b30 + a10 * b31 + a20 * b32 + a30 * b33;
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dest.row[3].y = a01 * b30 + a11 * b31 + a21 * b32 + a31 * b33;
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dest.row[3].z = a02 * b30 + a12 * b31 + a22 * b32 + a32 * b33;
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dest.row[3].w = a03 * b30 + a13 * b31 + a23 * b32 + a33 * b33;
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return dest;
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}
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static inline Matrix4 matrix_inverse(Matrix4 mat) {
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Matrix4 dest;
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float const
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a = mat.row[0].x, b = mat.row[0].y, c = mat.row[0].z, d = mat.row[0].w,
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e = mat.row[1].x, f = mat.row[1].y, g = mat.row[1].z, h = mat.row[1].w,
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i = mat.row[2].x, j = mat.row[2].y, k = mat.row[2].z, l = mat.row[2].w,
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m = mat.row[3].x, n = mat.row[3].y, o = mat.row[3].z, p = mat.row[3].w,
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c1 = k * p - l * o, c2 = c * h - d * g, c3 = i * p - l * m,
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c4 = a * h - d * e, c5 = j * p - l * n, c6 = b * h - d * f,
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c7 = i * n - j * m, c8 = a * f - b * e, c9 = j * o - k * n,
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c10 = b * g - c * f, c11 = i * o - k * m, c12 = a * g - c * e,
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idt = 1.0f/(c8*c1+c4*c9+c10*c3+c2*c7-c12*c5-c6*c11), ndt = -idt;
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dest.row[0].x = (f * c1 - g * c5 + h * c9) * idt;
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dest.row[0].y = (b * c1 - c * c5 + d * c9) * ndt;
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dest.row[0].z = (n * c2 - o * c6 + p * c10) * idt;
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dest.row[0].w = (j * c2 - k * c6 + l * c10) * ndt;
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dest.row[1].x = (e * c1 - g * c3 + h * c11) * ndt;
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dest.row[1].y = (a * c1 - c * c3 + d * c11) * idt;
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dest.row[1].z = (m * c2 - o * c4 + p * c12) * ndt;
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dest.row[1].w = (i * c2 - k * c4 + l * c12) * idt;
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dest.row[2].x = (e * c5 - f * c3 + h * c7) * idt;
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dest.row[2].y = (a * c5 - b * c3 + d * c7) * ndt;
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dest.row[2].z = (m * c6 - n * c4 + p * c8) * idt;
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dest.row[2].w = (i * c6 - j * c4 + l * c8) * ndt;
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dest.row[3].x = (e * c9 - f * c11 + g * c7) * ndt;
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dest.row[3].y = (a * c9 - b * c11 + c * c7) * idt;
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dest.row[3].z = (m * c10 - n * c12 + o * c8) * ndt;
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dest.row[3].w = (i * c10 - j * c12 + k * c8) * idt;
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return dest;
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}
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static inline Vec4 matrix_vector_multiply(Matrix4 m, Vec4 v) {
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Vec4 res;
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res.x = m.row[0].x * v.x + m.row[1].x * v.y + m.row[2].x * v.z + m.row[3].x * v.w;
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res.y = m.row[0].y * v.x + m.row[1].y * v.y + m.row[2].y * v.z + m.row[3].y * v.w;
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res.z = m.row[0].z * v.x + m.row[1].z * v.y + m.row[2].z * v.z + m.row[3].z * v.w;
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res.w = m.row[0].w * v.x + m.row[1].w * v.y + m.row[2].w * v.z + m.row[3].w * v.w;
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return res;
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}
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#endif
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