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-rw-r--r--example.h9
-rw-r--r--examples/perspective.c48
-rw-r--r--platform_win32.c17
-rw-r--r--sponge.h89
4 files changed, 157 insertions, 6 deletions
diff --git a/example.h b/example.h
index df671e1..29212aa 100644
--- a/example.h
+++ b/example.h
@@ -1,8 +1,11 @@
#include <stdint.h>
+#define PI ((float)3.14159265358979323846)
+
void init();
void draw_frame(sponge_Texture c);
void mouse_move(int32_t x, int32_t y);
+void draw_frame_3d(sponge_Texture c, float *depths);
#ifdef SPONGE_EXAMPLE_IMPLEMENTATION
@@ -14,4 +17,10 @@ void init() {}
void mouse_move(int32_t x, int32_t y) {}
#endif // SPONGE_EXAMPLE_MOUSE_MOVE_DEFINED
+#ifndef SPONGE_EXAMPLE_DRAW_FRAME_3D_DEFINED
+void draw_frame_3d(sponge_Texture c, float *depths) {
+ draw_frame(c);
+}
+#endif // SPONGE_EXAMPLE_DRAW_FRAME_3D_DEFINED
+
#endif // SPONGE_EXAMPLE_IMPLEMENTATION
diff --git a/examples/perspective.c b/examples/perspective.c
new file mode 100644
index 0000000..5a2e68a
--- /dev/null
+++ b/examples/perspective.c
@@ -0,0 +1,48 @@
+#include "../sponge.h"
+#define SPONGE_EXAMPLE_IMPLEMENTATION
+#define SPONGE_EXAMPLE_MOUSE_MOVE_DEFINED
+#define SPONGE_EXAMPLE_DRAW_FRAME_3D_DEFINED
+#include "../example.h"
+
+#define FOV (60.0f / PI * 2.0f)
+
+static int32_t mouse_x;
+static int32_t mouse_y;
+
+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_Vec3 positions[] = {
+ sponge_vec3_make(-0.5f, 0.5f, 0.0f),
+ sponge_vec3_make( 0.5f, 0.5f, 0.0f),
+ sponge_vec3_make(-0.5f, -0.5f, 0.0f),
+ sponge_vec3_make( 0.5f, -0.5f, 0.0f),
+ };
+
+ sponge_Color32 colors[] = {
+ sponge_color32_make(0xFF00FFFF),
+ sponge_color32_make(0xFFFFFFFF),
+ sponge_color32_make(0xFF0000FF),
+ sponge_color32_make(0xFFFF00FF),
+ };
+
+ int32_t triangles[] = {
+ 0, 1, 2,
+ 2, 1, 3,
+ };
+
+ sponge_Mat4 model = sponge_mat4_identity();
+ model = sponge_mat4_mul_mat4(model, sponge_mat4_rotate(
+ (float)(mouse_y - ((int32_t)c.height / 2)) / (float)c.height * PI,
+ (float)(mouse_x - ((int32_t)c.width / 2)) / (float)c.width * PI,
+ 0.0f));
+ model = sponge_mat4_mul_mat4(model, sponge_mat4_translate(0.0f, 0.0f, -5.0f));
+ sponge_Mat4 view = sponge_mat4_identity();
+ sponge_Mat4 proj = sponge_mat4_projection(FOV, (float)c.width / (float)c.height, 1.0f, 10.0f);
+ sponge_draw_mesh_col(c, depths, model, view, proj, positions, colors, triangles, 6);
+}
diff --git a/platform_win32.c b/platform_win32.c
index a8facc4..b8bb4b3 100644
--- a/platform_win32.c
+++ b/platform_win32.c
@@ -22,16 +22,23 @@
static size_t pixels_buffer_count;
static sponge_Texture canvas;
+static float *depths;
static BITMAPINFO bmi;
-int update_canvas(sponge_Texture *canvas, uint32_t new_width, uint32_t new_height) {
+int update_canvas(sponge_Texture *canvas, float **depths, uint32_t new_width, uint32_t new_height) {
size_t new_count = new_width * new_height;
if (new_count > pixels_buffer_count) {
sponge_Color32 *new_pixels_buffer = malloc(new_count * sizeof(uint32_t));
- if (!new_pixels_buffer)
+ float *new_depths = malloc(new_count * sizeof(float));
+ if (!new_pixels_buffer || !new_depths) {
+ free(new_pixels_buffer);
+ free(new_pixels_buffer);
return 0;
+ }
free(canvas->pixels);
+ free(*depths);
canvas->pixels = new_pixels_buffer;
+ *depths = new_depths;
pixels_buffer_count = new_count;
}
canvas->width = new_width;
@@ -73,7 +80,7 @@ LRESULT __stdcall WindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
uint32_t width = LOWORD(lParam);
uint32_t height = HIWORD(lParam);
// TODO(kard): handle properly? (what does that even mean)
- assert(update_canvas(&canvas, width, height));
+ assert(update_canvas(&canvas, &depths, width, height));
}
case WM_MOUSEMOVE: {
int32_t x = GET_X_LPARAM(lParam);
@@ -118,7 +125,7 @@ int __stdcall WinMain(
if (hwnd == NULL)
return 1;
- update_canvas(&canvas, DEFAULT_WIDTH, DEFAULT_HEIGHT);
+ update_canvas(&canvas, &depths, DEFAULT_WIDTH, DEFAULT_HEIGHT);
ShowWindow(hwnd, nShowCmd);
@@ -154,7 +161,7 @@ int __stdcall WinMain(
if (!running) break;
if (sponge_texture_valid(canvas))
- draw_frame(canvas);
+ draw_frame_3d(canvas, depths);
QueryPerformanceCounter(&qpc_end);
qpc_draw.QuadPart = qpc_end.QuadPart - qpc_start.QuadPart;
diff --git a/sponge.h b/sponge.h
index 5c9e435..7a4c283 100644
--- a/sponge.h
+++ b/sponge.h
@@ -1,7 +1,7 @@
#include <stdint.h>
+#include <math.h>
typedef union {
- // do not rely on byte order of this field (unless you only support one platform)
uint32_t value;
struct {
uint8_t b;
@@ -90,6 +90,7 @@ sponge_Mat4 sponge_mat4_translate(float x, float y, float z);
// TODO(kard): quaternion type beat
sponge_Mat4 sponge_mat4_rotate(float x, float y, float z); // y -> x -> z order
sponge_Mat4 sponge_mat4_scale(float x, float y, float z);
+sponge_Mat4 sponge_mat4_projection(float fov_y, float aspect, float near, float far); // right-handed, looking down -z
// checks if tex.width or tex.height is equal to 0
@@ -98,6 +99,7 @@ int32_t sponge_texture_valid(sponge_Texture tex);
// first argument is always rendering target (canvas)
void sponge_clear (sponge_Texture c, sponge_Color32 col);
+void sponge_clear_3d (sponge_Texture c, float *depths, sponge_Color32 col);
void sponge_draw_rect (sponge_Texture c, sponge_Vec2I v0, sponge_Vec2I v1, sponge_Color32 col);
void sponge_draw_line (sponge_Texture c, sponge_Vec2I v0, sponge_Vec2I v1, sponge_Color32 col);
@@ -127,6 +129,13 @@ void sponge_draw_triangle_uv(
sponge_Vec2I v0, sponge_Vec2I v1, sponge_Vec2I v2,
sponge_Vec2 uv0, sponge_Vec2 uv1, sponge_Vec2 uv2, sponge_Texture tex);
+
+void sponge_draw_mesh_col(
+ 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);
+
+
#define SPONGE_CLAMP(val, min, max) ((val) < (min) ? (min) : ((val) > (max) ? (max) : (val)))
#define SPONGE_MIN(x, y) ((x) < (y) ? (x) : (y))
#define SPONGE_MAX(x, y) ((x) > (y) ? (x) : (y))
@@ -299,6 +308,16 @@ sponge_Mat4 sponge_mat4_scale(float x, float y, float z) {
return m;
}
+sponge_Mat4 sponge_mat4_projection(float fov_y, float aspect, float znear, float zfar) {
+ float f = 1.0f / tanf(fov_y / 2.0f);
+ sponge_Mat4 m;
+ m.c00 = f / aspect; m.c01 = 0.0f; m.c02 = 0.0f; m.c03 = 0.0f;
+ m.c10 = 0.0f; m.c11 = f; m.c12 = 0.0f; m.c13 = 0.0f;
+ m.c20 = 0.0f; m.c21 = 0.0f; m.c22 = -zfar / (zfar - znear); m.c23 = (-znear * zfar) / (zfar - znear);
+ m.c30 = 0.0f; m.c31 = 0.0f; m.c32 = -1.0f; m.c33 = 0.0f;
+ return m;
+}
+
int32_t sponge_texture_valid(sponge_Texture tex) {
return tex.width != 0 && tex.height != 0 && tex.stride_pixels != 0;
@@ -314,6 +333,15 @@ void sponge_clear(sponge_Texture c, sponge_Color32 col) {
}
}
}
+void sponge_clear_3d(sponge_Texture c, float *depths, sponge_Color32 col) {
+ sponge_clear(c, col);
+ float *row = depths;
+ for (uint32_t y = 0; y < c.height; y++, row += c.stride_pixels) {
+ for (uint32_t x = 0; x < c.width; x++) {
+ row[x] = INFINITY;
+ }
+ }
+}
void sponge_draw_rect(sponge_Texture c, sponge_Vec2I v0, sponge_Vec2I v1, sponge_Color32 col) {
SPONGE_ASSERT(sponge_texture_valid(c));
@@ -474,4 +502,63 @@ void sponge_draw_triangle_uv(
}
}
+
+void sponge_draw_mesh_col(
+ 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
+) {
+ sponge_Mat4 mvp = sponge_mat4_mul_mat4(sponge_mat4_mul_mat4(model, view), proj);
+ for (size_t i = 0; i < triangles_count; i += 3) {
+ int32_t t0 = triangles[i + 0];
+ int32_t t1 = triangles[i + 1];
+ int32_t t2 = triangles[i + 2];
+
+ sponge_Vec3 v0 = positions[t0];
+ sponge_Vec3 v1 = positions[t1];
+ sponge_Vec3 v2 = positions[t2];
+
+ v0 = sponge_vec3_mul_mat4(v0, mvp);
+ v1 = sponge_vec3_mul_mat4(v1, mvp);
+ v2 = sponge_vec3_mul_mat4(v2, mvp);
+
+ // TODO(kard): clipping
+
+ sponge_Vec2I v0i = sponge_vec2i_make((int32_t)((v0.x + 1.0f) * (c.width / 2)), (int32_t)((v0.y + 1.0f) * (c.height / 2)));
+ sponge_Vec2I v1i = sponge_vec2i_make((int32_t)((v1.x + 1.0f) * (c.width / 2)), (int32_t)((v1.y + 1.0f) * (c.height / 2)));
+ sponge_Vec2I v2i = sponge_vec2i_make((int32_t)((v2.x + 1.0f) * (c.width / 2)), (int32_t)((v2.y + 1.0f) * (c.height / 2)));
+ v0i.y = c.height - v0i.y;
+ v1i.y = c.height - v1i.y;
+ v2i.y = c.height - v2i.y;
+
+
+ sponge_Vec2I min, max;
+ float area2;
+ sponge_draw_triangle_init(c, v0i, v1i, v2i, &min, &max, &area2);
+ sponge_Color32 *row = c.pixels + (min.y * c.stride_pixels);
+ float *depth_row = depths + (min.y * c.stride_pixels);
+
+ for (int32_t y = min.y; y <= max.y; y++, row += c.stride_pixels, depth_row += c.stride_pixels) {
+ for (int32_t x = min.x; x <= max.x; x++) {
+ float w0, w1, w2;
+ if (sponge_draw_triangle_iter(sponge_vec2i_make(x, y), v0i, v1i, v2i, area2, &w0, &w1, &w2)) {
+ float depth = (v0.z * w0) + (v1.z * w1) + (v2.z * w2);
+ if (depth < depth_row[x] && depth <= 1.0f && depth >= 0.0f) {
+ depth_row[x] = depth;
+
+ sponge_ColorF c0 = sponge_color32_to_colorf(colors[t0]);
+ sponge_ColorF c1 = sponge_color32_to_colorf(colors[t1]);
+ sponge_ColorF c2 = sponge_color32_to_colorf(colors[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));
+ row[x] = sponge_colorf_to_color32(result);
+ }
+ }
+ }
+ }
+ }
+}
+
#endif // SPONGE_IMPLEMENTATION
generated by cgit v1.3.1 (git 2.54.0) at 2026-06-04 02:58:12 +0000