luboslenco
133 lines
5.0 KiB
C
133 lines
5.0 KiB
C
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#include "global.h"
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raw_mesh_t *geom_make_plane(f32 size_x, f32 size_y, i32 verts_x, i32 verts_y, f32 uv_scale) {
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raw_mesh_t *mesh = GC_ALLOC_INIT(raw_mesh_t, {0});
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mesh->scale_pos = 1.0;
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mesh->scale_tex = uv_scale;
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mesh->name = "Plane";
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mesh->has_next = false;
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// Pack positions to (-1, 1) range
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f32 half_x = size_x / 2.0;
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f32 half_y = size_y / 2.0;
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mesh->scale_pos = math_max(size_x, size_y);
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f32 inv = (1 / (float)mesh->scale_pos) * 32767;
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mesh->posa = i16_array_create(verts_x * verts_y * 4);
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mesh->nora = i16_array_create(verts_x * verts_y * 2);
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mesh->texa = i16_array_create(verts_x * verts_y * 2);
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mesh->inda = u32_array_create((verts_x - 1) * (verts_y - 1) * 6);
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f32 step_x = size_x / (float)(verts_x - 1);
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f32 step_y = size_y / (float)(verts_y - 1);
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for (i32 i = 0; i < verts_x * verts_y; ++i) {
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f32 x = (i % verts_x) * step_x - half_x;
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f32 y = math_floor(i / (float)verts_x) * step_y - half_y;
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mesh->posa->buffer[i * 4] = math_floor(x * inv);
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mesh->posa->buffer[i * 4 + 1] = math_floor(y * inv);
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mesh->posa->buffer[i * 4 + 2] = 0;
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mesh->nora->buffer[i * 2] = 0;
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mesh->nora->buffer[i * 2 + 1] = 0;
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mesh->posa->buffer[i * 4 + 3] = 32767;
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x = (i % verts_x) / (float)(verts_x - 1);
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y = 1.0 - math_floor(i / (float)verts_x) / (float)(verts_y - 1);
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mesh->texa->buffer[i * 2] = math_floor(x * 32767);
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mesh->texa->buffer[i * 2 + 1] = math_floor(y * 32767);
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}
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for (i32 i = 0; i < (verts_x - 1) * (verts_y - 1); ++i) {
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f32 x = i % (verts_x - 1);
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f32 y = math_floor(i / (float)(verts_y - 1));
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mesh->inda->buffer[i * 6] = y * verts_x + x;
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mesh->inda->buffer[i * 6 + 1] = y * verts_x + x + 1;
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mesh->inda->buffer[i * 6 + 2] = (y + 1) * verts_x + x;
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mesh->inda->buffer[i * 6 + 3] = y * verts_x + x + 1;
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mesh->inda->buffer[i * 6 + 4] = (y + 1) * verts_x + x + 1;
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mesh->inda->buffer[i * 6 + 5] = (y + 1) * verts_x + x;
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}
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return mesh;
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}
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raw_mesh_t *geom_make_uv_sphere(f32 radius, i32 width_segments, i32 height_segments, bool stretch_uv, f32 uv_scale) {
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raw_mesh_t *mesh = GC_ALLOC_INIT(raw_mesh_t, {0});
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mesh->scale_pos = 1.0;
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mesh->scale_tex = 1.0;
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mesh->name = "Sphere";
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mesh->has_next = false;
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// Pack positions to (-1, 1) range
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mesh->scale_pos = radius;
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mesh->scale_tex = uv_scale;
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f32 inv = (1 / (float)mesh->scale_pos) * 32767;
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f32 pi2 = math_pi() * 2;
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i32 width_verts = width_segments + 1;
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i32 height_verts = height_segments + 1;
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mesh->posa = i16_array_create(width_verts * height_verts * 4);
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mesh->nora = i16_array_create(width_verts * height_verts * 2);
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mesh->texa = i16_array_create(width_verts * height_verts * 2);
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mesh->inda = u32_array_create(width_segments * height_segments * 6 - width_segments * 6);
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vec4_t nor = (vec4_t){0.0, 0.0, 0.0, 1.0};
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i32 pos = 0;
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for (i32 y = 0; y < height_verts; ++y) {
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f32 v = y / (float)height_segments;
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f32 v_flip = 1.0 - v;
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if (!stretch_uv) {
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v_flip /= 2;
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}
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f32 u_off = y == 0 ? 0.5 / (float)width_segments : y == height_segments ? -0.5 / (float)width_segments : 0.0;
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for (i32 x = 0; x < width_verts; ++x) {
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f32 u = x / (float)width_segments;
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f32 u_pi2 = u * pi2;
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f32 v_pi = v * math_pi();
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f32 v_pi_sin = math_sin(v_pi);
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f32 vx = -radius * math_cos(u_pi2) * v_pi_sin;
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f32 vy = radius * math_sin(u_pi2) * v_pi_sin;
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f32 vz = -radius * math_cos(v_pi);
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i32 i4 = pos * 4;
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i32 i2 = pos * 2;
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mesh->posa->buffer[i4] = math_floor(vx * inv);
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mesh->posa->buffer[i4 + 1] = math_floor(vy * inv);
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mesh->posa->buffer[i4 + 2] = math_floor(vz * inv);
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nor = (vec4_t){vx, vy, vz, 1.0};
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nor = vec4_norm(nor);
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mesh->posa->buffer[i4 + 3] = math_floor(nor.z * 32767);
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mesh->nora->buffer[i2] = math_floor(nor.x * 32767);
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mesh->nora->buffer[i2 + 1] = math_floor(nor.y * 32767);
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i32 tx = (math_floor((u + u_off) * 32767) - 1);
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i32 ty = (math_floor(v_flip * 32767) - 1);
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mesh->texa->buffer[i2] = tx % 32767;
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mesh->texa->buffer[i2 + 1] = ty % 32767;
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pos++;
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}
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}
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pos = 0;
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i32 height_segments1 = height_segments - 1;
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for (i32 y = 0; y < height_segments; ++y) {
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for (i32 x = 0; x < width_segments; ++x) {
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i32 x1 = x + 1;
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i32 y1 = y + 1;
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f32 a = y * width_verts + x1;
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f32 b = y * width_verts + x;
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f32 c = y1 * width_verts + x;
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f32 d = y1 * width_verts + x1;
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if (y > 0) {
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mesh->inda->buffer[pos++] = a;
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mesh->inda->buffer[pos++] = b;
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mesh->inda->buffer[pos++] = d;
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}
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if (y < height_segments1) {
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mesh->inda->buffer[pos++] = b;
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mesh->inda->buffer[pos++] = c;
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mesh->inda->buffer[pos++] = d;
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}
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}
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}
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return mesh;
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}
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