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#include <math.h>
#include <stdlib.h>
#include "../sponge.h"
#define SPONGE_EXAMPLE_IMPLEMENTATION
#define SPONGE_EXAMPLE_INIT_DEFINED
#define SPONGE_EXAMPLE_MOUSE_MOVE_DEFINED
#define SPONGE_EXAMPLE_DRAW_FRAME_3D_DEFINED
#include "example.h"
#define FOV (60.0f / PI * 2.0f)
#define DISTANCE (10.0f)
#define GOLDEN_RATIO (1.618033988749f)
static int32_t mouse_x;
static int32_t mouse_y;
static sponge_Vec3 positions[12];
static sponge_Color32 colors[12];
static sponge_Color32 colors_red[12];
static sponge_Color32 colors_green[12];
static sponge_Color32 colors_blue[12];
static int32_t triangles[20 * 3];
void make_icosahedron(sponge_Vec3 out_positions[12], int32_t out_triangles[20 * 3]) {
float a = sqrtf(1.0f / (1.0f + (GOLDEN_RATIO * GOLDEN_RATIO)));
float b = a * GOLDEN_RATIO;
out_positions[0] = sponge_vec3_make(0.0f, -a, b);
out_positions[1] = sponge_vec3_make(0.0f, a, b);
out_positions[2] = sponge_vec3_make(0.0f, -a, -b);
out_positions[3] = sponge_vec3_make(0.0f, a, -b);
out_positions[4] = sponge_vec3_make(-b, 0.0f, a);
out_positions[5] = sponge_vec3_make( b, 0.0f, a);
out_positions[6] = sponge_vec3_make(-b, 0.0f, -a);
out_positions[7] = sponge_vec3_make( b, 0.0f, -a);
out_positions[8] = sponge_vec3_make(-a, b, 0.0f);
out_positions[9] = sponge_vec3_make( a, b, 0.0f);
out_positions[10] = sponge_vec3_make(-a, -b, 0.0f);
out_positions[11] = sponge_vec3_make( a, -b, 0.0f);
size_t i = 0;
// 2x y
out_triangles[i++] = 4; out_triangles[i++] = 1; out_triangles[i++] = 0;
out_triangles[i++] = 0; out_triangles[i++] = 1; out_triangles[i++] = 5;
out_triangles[i++] = 3; out_triangles[i++] = 2; out_triangles[i++] = 7;
out_triangles[i++] = 2; out_triangles[i++] = 3; out_triangles[i++] = 6;
// 2y z
out_triangles[i++] = 4; out_triangles[i++] = 6; out_triangles[i++] = 8;
out_triangles[i++] = 10; out_triangles[i++] = 6; out_triangles[i++] = 4;
out_triangles[i++] = 7; out_triangles[i++] = 5; out_triangles[i++] = 9;
out_triangles[i++] = 5; out_triangles[i++] = 7; out_triangles[i++] = 11;
// 2z x
out_triangles[i++] = 8; out_triangles[i++] = 9; out_triangles[i++] = 1;
out_triangles[i++] = 3; out_triangles[i++] = 9; out_triangles[i++] = 8;
out_triangles[i++] = 0; out_triangles[i++] = 11; out_triangles[i++] = 10;
out_triangles[i++] = 10; out_triangles[i++] = 11; out_triangles[i++] = 2;
// xyz
out_triangles[i++] = 10; out_triangles[i++] = 4; out_triangles[i++] = 0;
out_triangles[i++] = 0; out_triangles[i++] = 5; out_triangles[i++] = 11;
out_triangles[i++] = 1; out_triangles[i++] = 4; out_triangles[i++] = 8;
out_triangles[i++] = 9; out_triangles[i++] = 5; out_triangles[i++] = 1;
out_triangles[i++] = 2; out_triangles[i++] = 6; out_triangles[i++] = 10;
out_triangles[i++] = 11; out_triangles[i++] = 7; out_triangles[i++] = 2;
out_triangles[i++] = 8; out_triangles[i++] = 6; out_triangles[i++] = 3;
out_triangles[i++] = 3; out_triangles[i++] = 7; out_triangles[i++] = 9;
}
// NOTE(kard):
// there are many ways to handle opacity and base library doesn't provide one.
// this example implementation requires caller to order objects back to front.
// you could allocate multiple canvases and merge them at the end (after sorting pixel based on depth).
void draw_mesh_col_transparent(
sponge_Texture c, float *depths,
sponge_Mat4 model, sponge_Mat4 view, sponge_Mat4 proj,
sponge_Vec3 *positions, sponge_Color32 *colors, int32_t *triangles, size_t triangles_count,
float opacity
) {
sponge_Mat4 mvp = sponge_mat4_mul_mat4(sponge_mat4_mul_mat4(model, view), proj);
for (size_t i = 0; i < triangles_count; i += 3) {
sponge_DrawMeshTriangleContext ctx = sponge_draw_mesh_triangle_init(c, mvp, positions, triangles, i);
sponge_Color32 *row = c.pixels + (ctx.min_pixel.y * c.stride_pixels);
float *depth_row = depths + (ctx.min_pixel.y * c.stride_pixels);
for (int32_t y = ctx.min_pixel.y; y <= ctx.max_pixel.y; y++, row += c.stride_pixels, depth_row += c.stride_pixels) {
for (int32_t x = ctx.min_pixel.x; x <= ctx.max_pixel.x; x++) {
float w0, w1, w2;
if (sponge_draw_mesh_triangle_iter(ctx, sponge_vec2i_make(x, y), &depth_row[x], &w0, &w1, &w2)) {
sponge_ColorF c0 = sponge_color32_to_colorf(colors[ctx.t0]);
sponge_ColorF c1 = sponge_color32_to_colorf(colors[ctx.t1]);
sponge_ColorF c2 = sponge_color32_to_colorf(colors[ctx.t2]);
sponge_ColorF result = sponge_vec4_make(0.0f, 0.0f, 0.0f, 0.0f);
result = sponge_vec4_add(result, sponge_vec4_mul(c0, w0));
result = sponge_vec4_add(result, sponge_vec4_mul(c1, w1));
result = sponge_vec4_add(result, sponge_vec4_mul(c2, w2));
sponge_ColorF cur = sponge_color32_to_colorf(row[x]);
result = sponge_vec4_add(cur, sponge_vec4_mul(sponge_vec4_sub(result, cur), opacity));
row[x] = sponge_colorf_to_color32(result);
}
}
}
}
}
void init() {
make_icosahedron(positions, triangles);
sponge_Vec3 light = sponge_vec3_make(1.0f, 1.0f, 1.0f);
float len = (light.x * light.x) + (light.y * light.y) + (light.z * light.z);
len = sqrtf(len);
light = sponge_vec3_mul(light, 1.0f / len);
for (uint32_t i = 0; i < 12; i++) {
sponge_Vec3 v = positions[i];
float value = v.x * light.x + v.y * light.y + v.z * light.z;
value = SPONGE_CLAMP(value, 0.1f, 1.0f);
sponge_ColorF color = sponge_vec4_make(1.0f, value, value, value);
color = sponge_vec4_mul(color, 255.0f);
colors[i] = sponge_colorf_to_color32(color);
colors_red[i] = sponge_color32_make(0xFFFF0000);
colors_green[i] = sponge_color32_make(0xFF00FF00);
colors_blue[i] = sponge_color32_make(0xFF0000FF);
//sponge_Vec3 v = sponge_vec3_mul(positions[i], 255.0f);
//colors[i] = sponge_colorf_to_color32(sponge_vec4_make(1.0f, SPONGE_ABS(v.x), SPONGE_ABS(v.y), SPONGE_ABS(v.z)));
}
}
void mouse_move(int32_t x, int32_t y) {
mouse_x = x;
mouse_y = y;
}
void draw_frame_3d(sponge_Texture c, float *depths) {
sponge_clear_3d(c, depths, sponge_color32_make(0xFF000000));
sponge_Mat4 model = sponge_mat4_translate(2.0f, 0.0f, 0.0f);
sponge_Mat4 rotate = sponge_mat4_rotate(0.0f, 90.0f / 360.0f * PI * 2.0f, 0.0f);
sponge_Mat4 model_red = sponge_mat4_mul_mat4(model, rotate);
sponge_Mat4 model_green = sponge_mat4_mul_mat4(model_red, rotate);
sponge_Mat4 model_blue = sponge_mat4_mul_mat4(model_green, rotate);
float rot_y = (float)mouse_x / (float)c.width * PI * 2.0f;
float rot_x = ((float)mouse_y / (float)c.height * PI) - (PI * 0.5f);
sponge_Mat4 view = sponge_mat4_identity();
view = sponge_mat4_mul_mat4(view, sponge_mat4_rotate(rot_x, rot_y, 0.0f));
view = sponge_mat4_mul_mat4(view, sponge_mat4_translate(0.0f, 0.0f, -10.0f));
sponge_Mat4 proj = sponge_mat4_projection(FOV, (float)c.width / (float)c.height, 1.0f, 100.0f);
sponge_draw_mesh_col(c, depths, model, view, proj, positions, colors, triangles, 60);
float z0 = sponge_vec3_mul_mat4(sponge_vec3_make(0.0f, 0.0f, 0.0f), sponge_mat4_mul_mat4(model_red, view)).z;
float z1 = sponge_vec3_mul_mat4(sponge_vec3_make(0.0f, 0.0f, 0.0f), sponge_mat4_mul_mat4(model_green, view)).z;
float z2 = sponge_vec3_mul_mat4(sponge_vec3_make(0.0f, 0.0f, 0.0f), sponge_mat4_mul_mat4(model_blue, view)).z;
float z[3] = { z0, z1, z2 };
int order[3] = { 0, 1, 2 };
// do not look at this garbage
if (z[order[0]] > z[order[1]]) {
int tmp = order[0];
order[0] = order[1];
order[1] = tmp;
}
if (z[order[0]] > z[order[2]]) {
int tmp = order[0];
order[0] = order[2];
order[2] = tmp;
}
if (z[order[1]] > z[order[2]]) {
int tmp = order[1];
order[1] = order[2];
order[2] = tmp;
}
for (int i = 0; i < 3; i++) {
switch(order[i]) {
case 0:
draw_mesh_col_transparent(c, depths, model_red, view, proj, positions, colors_red, triangles, 60, 0.1f);
break;
case 1:
draw_mesh_col_transparent(c, depths, model_green, view, proj, positions, colors_green, triangles, 60, 0.2f);
break;
case 2:
draw_mesh_col_transparent(c, depths, model_blue, view, proj, positions, colors_blue, triangles, 60, 0.3f);
break;
}
}
}
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