wip procgen

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asrael 2025-11-09 06:30:17 -06:00
parent a653eae745
commit 79a678f162
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GPG key ID: 2786557804DFAE24
18 changed files with 1317 additions and 127 deletions

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@ -42,12 +42,18 @@ struct pxl8_gfx {
pxl8_mat4 model;
pxl8_mat4 projection;
pxl8_mat4 view;
pxl8_mat4 mvp;
bool mvp_dirty;
pxl8_frustum frustum;
bool wireframe;
f32* zbuffer;
i32 zbuffer_height;
i32 zbuffer_width;
bool affine_textures;
u32 frame_triangle_count;
u32 frame_pixel_count;
};
static inline void pxl8_color_unpack(u32 color, u8* r, u8* g, u8* b, u8* a) {
@ -191,6 +197,7 @@ pxl8_gfx* pxl8_gfx_create(
gfx->model = pxl8_mat4_identity();
gfx->projection = pxl8_mat4_identity();
gfx->view = pxl8_mat4_identity();
gfx->mvp_dirty = true;
gfx->wireframe = false;
gfx->zbuffer = NULL;
gfx->zbuffer_height = 0;
@ -403,10 +410,23 @@ void pxl8_gfx_project(pxl8_gfx* gfx, f32 left, f32 right, f32 top, f32 bottom) {
void pxl8_clr(pxl8_gfx* gfx, u32 color) {
if (!gfx || !gfx->framebuffer) return;
static u32 frame_count = 0;
if (gfx->frame_triangle_count > 0) {
if (frame_count % 60 == 0) {
i32 fb_pixels = gfx->framebuffer_width * gfx->framebuffer_height;
f32 overdraw = (f32)gfx->frame_pixel_count / (f32)fb_pixels;
pxl8_debug("Frame triangles: %u, pixels: %u, overdraw: %.2fx",
gfx->frame_triangle_count, gfx->frame_pixel_count, overdraw);
}
frame_count++;
}
gfx->frame_triangle_count = 0;
gfx->frame_pixel_count = 0;
i32 bytes_per_pixel = (gfx->color_mode == PXL8_COLOR_MODE_HICOLOR) ? 4 : 1;
i32 size = gfx->framebuffer_width * gfx->framebuffer_height;
if (bytes_per_pixel == 4) {
u32* fb32 = (u32*)gfx->framebuffer;
for (i32 i = 0; i < size; i++) {
@ -786,9 +806,33 @@ static bool pxl8_3d_init_zbuffer(pxl8_gfx* gfx) {
void pxl8_3d_clear_zbuffer(pxl8_gfx* gfx) {
if (!gfx || !gfx->zbuffer) return;
for (i32 i = 0; i < gfx->zbuffer_width * gfx->zbuffer_height; i++) {
gfx->zbuffer[i] = 1e30f;
i32 count = gfx->zbuffer_width * gfx->zbuffer_height;
const f32 far_z = 1e30f;
#if defined(PXL8_SIMD_NEON)
float32x4_t far_vec = vdupq_n_f32(far_z);
i32 i = 0;
for (; i + 3 < count; i += 4) {
vst1q_f32(&gfx->zbuffer[i], far_vec);
}
for (; i < count; i++) {
gfx->zbuffer[i] = far_z;
}
#elif defined(PXL8_SIMD_SSE2)
__m128 far_vec = _mm_set1_ps(far_z);
i32 i = 0;
for (; i + 3 < count; i += 4) {
_mm_store_ps(&gfx->zbuffer[i], far_vec);
}
for (; i < count; i++) {
gfx->zbuffer[i] = far_z;
}
#else
for (i32 i = 0; i < count; i++) {
gfx->zbuffer[i] = far_z;
}
#endif
}
void pxl8_3d_set_backface_culling(pxl8_gfx* gfx, bool culling) {
@ -799,16 +843,19 @@ void pxl8_3d_set_backface_culling(pxl8_gfx* gfx, bool culling) {
void pxl8_3d_set_model(pxl8_gfx* gfx, pxl8_mat4 mat) {
if (!gfx) return;
gfx->model = mat;
gfx->mvp_dirty = true;
}
void pxl8_3d_set_projection(pxl8_gfx* gfx, pxl8_mat4 mat) {
if (!gfx) return;
gfx->projection = mat;
gfx->mvp_dirty = true;
}
void pxl8_3d_set_view(pxl8_gfx* gfx, pxl8_mat4 mat) {
if (!gfx) return;
gfx->view = mat;
gfx->mvp_dirty = true;
}
void pxl8_3d_set_wireframe(pxl8_gfx* gfx, bool wireframe) {
@ -821,7 +868,27 @@ void pxl8_3d_set_affine_textures(pxl8_gfx* gfx, bool affine) {
gfx->affine_textures = affine;
}
static inline void pxl8_update_mvp(pxl8_gfx* gfx) {
if (!gfx->mvp_dirty) return;
gfx->mvp = pxl8_mat4_multiply(gfx->projection,
pxl8_mat4_multiply(gfx->view, gfx->model));
pxl8_mat4 vp = pxl8_mat4_multiply(gfx->projection, gfx->view);
gfx->frustum = pxl8_frustum_from_matrix(vp);
gfx->mvp_dirty = false;
}
const pxl8_frustum* pxl8_3d_get_frustum(pxl8_gfx* gfx) {
if (!gfx) return NULL;
pxl8_update_mvp(gfx);
return &gfx->frustum;
}
static inline pxl8_vec4 pxl8_transform_vertex(pxl8_gfx* gfx, pxl8_vec3 pos) {
pxl8_update_mvp(gfx);
pxl8_vec4 v = {
.x = pos.x,
.y = pos.y,
@ -829,10 +896,7 @@ static inline pxl8_vec4 pxl8_transform_vertex(pxl8_gfx* gfx, pxl8_vec3 pos) {
.w = 1.0f,
};
pxl8_mat4 mvp = pxl8_mat4_multiply(gfx->projection,
pxl8_mat4_multiply(gfx->view, gfx->model));
return pxl8_mat4_multiply_vec4(mvp, v);
return pxl8_mat4_multiply_vec4(gfx->mvp, v);
}
static inline void pxl8_project_to_screen(pxl8_gfx* gfx, pxl8_vec4 clip, i32* x, i32* y, f32* z) {
@ -865,23 +929,82 @@ void pxl8_3d_draw_line_3d(pxl8_gfx* gfx, pxl8_vec3 p0, pxl8_vec3 p1, u32 color)
pxl8_line(gfx, x0, y0, x1, y1, color);
}
static inline void pxl8_fill_scanline(pxl8_gfx* gfx, i32 y, i32 xs, i32 xe, f32 z0, f32 z1, u32 color) {
static inline void pxl8_fill_scanline_hicolor(pxl8_gfx* gfx, i32 y, i32 xs, i32 xe, f32 z0, f32 z1, u32 color) {
if (y < 0 || y >= gfx->framebuffer_height) return;
if (xs > xe) {
i32 tmp = xs; xs = xe; xe = tmp;
f32 tmpz = z0; z0 = z1; z1 = tmpz;
}
for (i32 x = xs; x <= xe; x++) {
if (x >= 0 && x < gfx->framebuffer_width) {
f32 t = (xe == xs) ? 0.0f : (f32)(x - xs) / (f32)(xe - xs);
f32 z = z0 + t * (z1 - z0);
if (xs < 0) xs = 0;
if (xe >= gfx->framebuffer_width) xe = gfx->framebuffer_width - 1;
if (xs > xe) return;
i32 idx = y * gfx->zbuffer_width + x;
if (z <= gfx->zbuffer[idx]) {
gfx->zbuffer[idx] = z;
pxl8_pixel(gfx, x, y, color);
}
i32 width = xe - xs;
if (width == 0) {
i32 idx = y * gfx->zbuffer_width + xs;
if (z0 <= gfx->zbuffer[idx]) {
gfx->zbuffer[idx] = z0;
i32 fb_idx = y * gfx->framebuffer_width + xs;
((u32*)gfx->framebuffer)[fb_idx] = color;
}
return;
}
f32 dz = (z1 - z0) / (f32)width;
f32 z = z0;
i32 zbuf_offset = y * gfx->zbuffer_width;
i32 fb_offset = y * gfx->framebuffer_width;
u32* fb = (u32*)gfx->framebuffer;
for (i32 x = xs; x <= xe; x++) {
i32 idx = zbuf_offset + x;
if (z <= gfx->zbuffer[idx]) {
gfx->zbuffer[idx] = z;
fb[fb_offset + x] = color;
}
z += dz;
}
}
static inline void pxl8_fill_scanline_indexed(pxl8_gfx* gfx, i32 y, i32 xs, i32 xe, f32 z0, f32 z1, u32 color) {
if (y < 0 || y >= gfx->framebuffer_height) return;
if (xs > xe) {
i32 tmp = xs; xs = xe; xe = tmp;
f32 tmpz = z0; z0 = z1; z1 = tmpz;
}
if (xs < 0) xs = 0;
if (xe >= gfx->framebuffer_width) xe = gfx->framebuffer_width - 1;
if (xs > xe) return;
i32 width = xe - xs;
u8 idx_color = color & 0xFF;
if (width == 0) {
i32 idx = y * gfx->zbuffer_width + xs;
if (z0 <= gfx->zbuffer[idx]) {
gfx->zbuffer[idx] = z0;
i32 fb_idx = y * gfx->framebuffer_width + xs;
gfx->framebuffer[fb_idx] = idx_color;
}
return;
}
f32 dz = (z1 - z0) / (f32)width;
f32 z = z0;
i32 zbuf_offset = y * gfx->zbuffer_width;
i32 fb_offset = y * gfx->framebuffer_width;
for (i32 x = xs; x <= xe; x++) {
i32 idx = zbuf_offset + x;
if (z <= gfx->zbuffer[idx]) {
gfx->zbuffer[idx] = z;
gfx->framebuffer[fb_offset + x] = idx_color;
}
z += dz;
}
}
@ -927,47 +1050,117 @@ static inline void pxl8_fill_scanline_textured(
tmpf = w0; w0 = w1; w1 = tmpf;
}
for (i32 x = xs; x <= xe; x++) {
if (x >= 0 && x < gfx->framebuffer_width) {
f32 t = (xe == xs) ? 0.0f : (f32)(x - xs) / (f32)(xe - xs);
f32 z = z0 + t * (z1 - z0);
i32 idx = y * gfx->zbuffer_width + x;
if (z <= gfx->zbuffer[idx]) {
f32 u = u0 + t * (u1 - u0);
f32 v = v0 + t * (v1 - v0);
if (!gfx->affine_textures) {
f32 w = w0 + t * (w1 - w0);
if (fabsf(w) > 1e-6f) {
u /= w;
v /= w;
}
i32 span = xe - xs;
if (span <= 0) {
if (xs >= 0 && xs < gfx->framebuffer_width) {
i32 idx = y * gfx->zbuffer_width + xs;
if (z0 <= gfx->zbuffer[idx]) {
gfx->frame_pixel_count++;
f32 u = u0, v = v0;
if (!gfx->affine_textures && fabsf(w0) > 1e-6f) {
u /= w0;
v /= w0;
}
u32 color = pxl8_sample_texture(gfx, texture_id, u, v);
if (gfx->color_mode == PXL8_COLOR_MODE_HICOLOR) {
if (color & 0xFF000000) {
gfx->zbuffer[idx] = z;
pxl8_pixel(gfx, x, y, color);
}
} else {
if (color != 0) {
if ((gfx->color_mode == PXL8_COLOR_MODE_HICOLOR && (color & 0xFF000000)) ||
(gfx->color_mode != PXL8_COLOR_MODE_HICOLOR && color != 0)) {
gfx->zbuffer[idx] = z0;
pxl8_pixel(gfx, xs, y, color);
}
}
}
return;
}
f32 inv_span = 1.0f / (f32)span;
f32 dz = (z1 - z0) * inv_span;
f32 du = (u1 - u0) * inv_span;
f32 dv = (v1 - v0) * inv_span;
f32 dw = (w1 - w0) * inv_span;
f32 z = z0;
f32 u = u0;
f32 v = v0;
f32 w = w0;
if (gfx->affine_textures) {
for (i32 x = xs; x <= xe; x++) {
if (x >= 0 && x < gfx->framebuffer_width) {
i32 idx = y * gfx->zbuffer_width + x;
if (z <= gfx->zbuffer[idx]) {
gfx->frame_pixel_count++;
u32 color = pxl8_sample_texture(gfx, texture_id, u, v);
if ((gfx->color_mode == PXL8_COLOR_MODE_HICOLOR && (color & 0xFF000000)) ||
(gfx->color_mode != PXL8_COLOR_MODE_HICOLOR && color != 0)) {
gfx->zbuffer[idx] = z;
pxl8_pixel(gfx, x, y, color);
}
}
}
z += dz;
u += du;
v += dv;
}
} else {
i32 x = xs;
while (x <= xe) {
f32 w_inv = (fabsf(w) > 1e-6f) ? (1.0f / w) : 0.0f;
f32 u_corrected = u * w_inv;
f32 v_corrected = v * w_inv;
i32 span_end = (x + 16 <= xe) ? (x + 16) : (xe + 1);
i32 span_len = span_end - x;
f32 next_u, next_v, affine_du, affine_dv;
if (span_len > 1) {
f32 next_w = w + span_len * dw;
f32 next_w_inv = (fabsf(next_w) > 1e-6f) ? (1.0f / next_w) : 0.0f;
next_u = (u + span_len * du) * next_w_inv;
next_v = (v + span_len * dv) * next_w_inv;
f32 inv_span = 1.0f / (f32)span_len;
affine_du = (next_u - u_corrected) * inv_span;
affine_dv = (next_v - v_corrected) * inv_span;
} else {
affine_du = 0;
affine_dv = 0;
}
f32 affine_u = u_corrected;
f32 affine_v = v_corrected;
for (; x < span_end; x++) {
if (x >= 0 && x < gfx->framebuffer_width) {
i32 idx = y * gfx->zbuffer_width + x;
if (z <= gfx->zbuffer[idx]) {
gfx->frame_pixel_count++;
u32 color = pxl8_sample_texture(gfx, texture_id, affine_u, affine_v);
if ((gfx->color_mode == PXL8_COLOR_MODE_HICOLOR && (color & 0xFF000000)) ||
(gfx->color_mode != PXL8_COLOR_MODE_HICOLOR && color != 0)) {
gfx->zbuffer[idx] = z;
pxl8_pixel(gfx, x, y, color);
}
}
}
z += dz;
u += du;
v += dv;
w += dw;
affine_u += affine_du;
affine_v += affine_dv;
}
}
}
}
typedef void (*pxl8_scanline_func)(pxl8_gfx*, i32, i32, i32, f32, f32, u32);
static void pxl8_draw_flat_bottom_triangle(
pxl8_gfx* gfx,
i32 x0, i32 y0, f32 z0,
i32 x1, i32 y1, f32 z1,
i32 x2, i32 y2, f32 z2,
u32 color
u32 color,
pxl8_scanline_func fill_scanline
) {
(void)z2;
if (y1 == y0) return;
@ -979,7 +1172,7 @@ static void pxl8_draw_flat_bottom_triangle(
f32 cur_x2 = (f32)x0;
for (i32 y = y0; y <= y1; y++) {
pxl8_fill_scanline(gfx, y, (i32)cur_x1, (i32)cur_x2, z0, z1, color);
fill_scanline(gfx, y, (i32)cur_x1, (i32)cur_x2, z0, z1, color);
cur_x1 += inv_slope_1;
cur_x2 += inv_slope_2;
}
@ -990,7 +1183,8 @@ static void pxl8_draw_flat_top_triangle(
i32 x0, i32 y0, f32 z0,
i32 x1, i32 y1, f32 z1,
i32 x2, i32 y2, f32 z2,
u32 color
u32 color,
pxl8_scanline_func fill_scanline
) {
(void)z2;
if (y2 == y0) return;
@ -1002,7 +1196,7 @@ static void pxl8_draw_flat_top_triangle(
f32 cur_x2 = (f32)x2;
for (i32 y = y2; y > y0; y--) {
pxl8_fill_scanline(gfx, y, (i32)cur_x1, (i32)cur_x2, z0, z1, color);
fill_scanline(gfx, y, (i32)cur_x1, (i32)cur_x2, z0, z1, color);
cur_x1 -= inv_slope_1;
cur_x2 -= inv_slope_2;
}
@ -1022,6 +1216,8 @@ void pxl8_3d_draw_triangle_raw(pxl8_gfx* gfx, pxl8_vec3 v0, pxl8_vec3 v1, pxl8_v
void pxl8_3d_draw_triangle(pxl8_gfx* gfx, pxl8_triangle tri) {
if (!gfx || !pxl8_3d_init_zbuffer(gfx)) return;
gfx->frame_triangle_count++;
pxl8_vec4 v0 = pxl8_transform_vertex(gfx, tri.v[0].position);
pxl8_vec4 v1 = pxl8_transform_vertex(gfx, tri.v[1].position);
pxl8_vec4 v2 = pxl8_transform_vertex(gfx, tri.v[2].position);
@ -1065,17 +1261,21 @@ void pxl8_3d_draw_triangle(pxl8_gfx* gfx, pxl8_triangle tri) {
u32 color = tri.v[0].color;
pxl8_scanline_func fill_scanline = (gfx->color_mode == PXL8_COLOR_MODE_HICOLOR)
? pxl8_fill_scanline_hicolor
: pxl8_fill_scanline_indexed;
if (y1 == y2) {
pxl8_draw_flat_bottom_triangle(gfx, x0, y0, z0, x1, y1, z1, x2, y2, z2, color);
pxl8_draw_flat_bottom_triangle(gfx, x0, y0, z0, x1, y1, z1, x2, y2, z2, color, fill_scanline);
} else if (y0 == y1) {
pxl8_draw_flat_top_triangle(gfx, x0, y0, z0, x1, y1, z1, x2, y2, z2, color);
pxl8_draw_flat_top_triangle(gfx, x0, y0, z0, x1, y1, z1, x2, y2, z2, color, fill_scanline);
} else {
i32 x3 = x0 + (i32)(((f32)(y1 - y0) / (f32)(y2 - y0)) * (x2 - x0));
i32 y3 = y1;
f32 z3 = z0 + ((f32)(y1 - y0) / (f32)(y2 - y0)) * (z2 - z0);
pxl8_draw_flat_bottom_triangle(gfx, x0, y0, z0, x1, y1, z1, x3, y3, z3, color);
pxl8_draw_flat_top_triangle(gfx, x1, y1, z1, x3, y3, z3, x2, y2, z2, color);
pxl8_draw_flat_bottom_triangle(gfx, x0, y0, z0, x1, y1, z1, x3, y3, z3, color, fill_scanline);
pxl8_draw_flat_top_triangle(gfx, x1, y1, z1, x3, y3, z3, x2, y2, z2, color, fill_scanline);
}
}