Initial commit.

1 files changed, 380 insertions, 0 deletions

diff --git a/render.c b/render.c
new file mode 100644
index 0000000..e291e7d
--- /dev/null
+++ b/render.c
@@ -0,0 +1,380 @@
+#include "plat.h"
+#include "maths.h"
+#include "render.h"
+
+static struct {
+	Rectangle clip;
+} renderer;
+
+Colour make_colour(unsigned rgb, unsigned char a) {
+	Colour r;
+	r.r = (unsigned char)(rgb >> 16);
+	r.g = (unsigned char)(rgb >> 8);
+	r.b = (unsigned char)rgb;
+	r.a = a;
+	return r;
+}
+
+Colour make_black() {
+	Colour r = { 0, 0, 0, 255 };
+	return r;
+}
+
+Colour make_white() {
+	return make_colour(0xffffff, 255);
+}
+
+void init_bitmap(
+	Bitmap* bitmap,
+	Colour* pixels,
+	int w,
+	int h
+) {
+	bitmap->pixels = pixels;
+	bitmap->w = w;
+	bitmap->h = h;
+}
+
+void render_init(void) {
+	int i, e;
+	Colour b, * p;
+	b = make_black();
+	p = get_fb();
+	e = get_render_w() * get_render_h();
+	for (i = 0; i < e; i++)
+		p[i] = b;
+}
+
+void render_begin(void) {
+	int i, e;
+	Colour b, * p;
+	b = make_black();
+	p = get_fb();
+	e = get_render_w() * get_render_h();
+	for (i = 0; i < e; i++)
+		p[i] = b;
+	render_reset_clip();
+}
+
+void render_clear(void) {
+	render_clear_col(make_black());
+}
+
+void render_clear_col(Colour col) {
+	Colour* d;
+	int ox, x, y, ex, ey, w;
+	d = get_fb();
+	x  = renderer.clip.x;
+	y  = renderer.clip.y;
+	ex = renderer.clip.w;
+	ey = renderer.clip.h;
+	ox = x;
+	w = get_render_w();
+	for (; y < ey; y++)
+		for (x = ox; x < ex; x++)
+			d[x + y * w] = col;
+}
+
+void render_clip(const Rectangle* rect) {
+	renderer.clip = *rect;
+	renderer.clip.x = maxi(renderer.clip.x, 0);
+	renderer.clip.y = maxi(renderer.clip.y, 0);
+	renderer.clip.w = mini(
+		renderer.clip.w,
+		get_render_w()
+	);
+	renderer.clip.h = mini(
+		renderer.clip.h,
+		get_render_h()
+	);
+}
+
+void render_reset_clip(void) {
+	renderer.clip.x = 0;
+	renderer.clip.y = 0;
+	renderer.clip.w = get_render_w();
+	renderer.clip.h = get_render_h();
+}
+
+Colour* get_render_pixels(void) {
+	return get_fb();
+}
+
+Colour blend(Colour dst, Colour src) {
+	int ima;
+
+	ima = 0xff - src.a;
+	dst.r = (unsigned char)(((src.r * src.a) + (dst.r * ima)) >> 8);
+	dst.g = (unsigned char)(((src.g * src.a) + (dst.g * ima)) >> 8);
+	dst.b = (unsigned char)(((src.b * src.a) + (dst.b * ima)) >> 8);
+
+	return dst;
+}
+
+Colour blend_mod(Colour dst, Colour src, Colour mod) {
+	int ima;
+
+	src.a = (src.a * mod.a) >> 8;
+	ima = 0xff - src.a;
+	dst.r = (unsigned char)(((src.r * mod.r * src.a) >> 16) + ((dst.r * ima) >> 8));
+	dst.g = (unsigned char)(((src.g * mod.g * src.a) >> 16) + ((dst.g * ima) >> 8));
+	dst.b = (unsigned char)(((src.b * mod.b * src.a) >> 16) + ((dst.b * ima) >> 8));
+
+	return dst;
+}
+
+#define blit_vars(t_) \
+	int i, j, stride, sstride, n; \
+	Colour* dst; \
+	const t_* src; \
+	Rectangle sub;
+#define blit( \
+	src_, \
+	dst_, \
+	pitch_, \
+	clip_, \
+	src_w_, \
+	src_h_, \
+	expr_ \
+) \
+	sub = *rect; \
+	if (sub.w <= 0) { goto end; } \
+	if (sub.h <= 0) { goto end; } \
+	if (sub.w > (src_w_)) { goto end; } \
+	if (sub.h > (src_h_)) { goto end; } \
+	if ((n = (clip_).x - x) > 0) { \
+		sub.w -= n; \
+		sub.x += n; \
+		x += n; \
+	} \
+	if ((n = (clip_).y - y) > 0) { \
+		sub.h -= n; \
+		sub.y += n; \
+		y += n; \
+	} \
+	if ((n = x + sub.w - (clip_).w) > 0) { \
+		sub.w -= n; \
+	} \
+	if ((n = y + sub.h - (clip_).h) > 0) { \
+		sub.h -= n; \
+	} \
+	if (sub.w <= 0) { goto end; } \
+	if (sub.h <= 0) { goto end; } \
+	dst = (dst_) + (x + y * (pitch_)); \
+	src = (src_) + (sub.x + sub.y * (src_w_)); \
+	stride = (pitch_) - sub.w; \
+	sstride = (src_w_) - sub.w; \
+	for (i = 0; i < sub.h; i++) { \
+		for (j = 0; j < sub.w; j++) { \
+			expr_; \
+			dst++; \
+			src++; \
+		} \
+		dst += stride; \
+		src += sstride; \
+	} \
+	end:
+
+#define blit_rect_vars \
+	int x1, y1, x2, y2, dr, j, i; \
+	Colour* dst;
+#define blit_rect(dst_, pitch_, clip_) \
+	x1 = rect->x < (clip_).x ? (clip_).x : rect->x; \
+	y1 = rect->y < (clip_).y ? (clip_).y : rect->y; \
+	x2 = rect->x + rect->w; \
+	y2 = rect->y + rect->h; \
+	x2 = x2 > (clip_).w? (clip_).w: x2; \
+	y2 = y2 > (clip_).h? (clip_).h: y2; \
+	dst = dst_; \
+	dst += x1 + y1 * pitch_; \
+	dr = pitch_ - (x2 - x1); \
+	for (j = y1; j < y2; j++) { \
+		for (i = x1; i < x2; i++) { \
+			*dst = blend(*dst, colour); \
+			dst++; \
+		} \
+		dst += dr; \
+	}
+
+void render_bitmap(
+	const Bitmap* bitmap,
+	int x,
+	int y,
+	const Rectangle* rect
+) {
+	blit_vars(Colour)
+	int renderer_w;
+	Colour* renderer_pixels;
+	renderer_w = get_render_w();
+	renderer_pixels = get_fb();
+	blit(
+		bitmap->pixels,
+		renderer_pixels,
+		renderer_w,
+		renderer.clip,
+		bitmap->w,
+		bitmap->h,
+		*dst = blend(*dst, *src)
+	);
+}
+
+void render_bitmap_col(
+	const Bitmap* bitmap,
+	int x,
+	int y,
+	const Rectangle* rect,
+	Colour colour
+) {
+	blit_vars(Colour)
+	int renderer_w;
+	Colour* renderer_pixels;
+	renderer_w = get_render_w();
+	renderer_pixels = get_fb();
+	blit(
+		bitmap->pixels,
+		renderer_pixels,
+		renderer_w,
+		renderer.clip,
+		bitmap->w,
+		bitmap->h,
+		*dst = blend_mod(*dst, *src, colour)
+	);
+}
+
+void render_mask(
+	const unsigned char* pixels,
+	int x,
+	int y,
+	int w,
+	int h,
+	const Rectangle* rect,
+	Colour colour
+) {
+	blit_vars(unsigned char)
+	int renderer_w;
+	Colour c;
+	Colour* renderer_pixels;
+	renderer_w = get_render_w();
+	renderer_pixels = get_fb();
+	c = colour;
+	blit(
+		pixels,
+		renderer_pixels,
+		renderer_w,
+		renderer.clip,
+		w,
+		h,
+		{
+			c.a = colour.a * *src;
+			*dst = blend(*dst, c);
+		}
+	);
+}
+
+void render_rect(
+	const Rectangle* rect,
+	Colour colour
+) {
+	blit_rect_vars
+	int renderer_w;
+	Colour* renderer_pixels;
+	renderer_w = get_render_w();
+	renderer_pixels = get_fb();
+	blit_rect(
+		renderer_pixels,
+		renderer_w,
+		renderer.clip
+	);
+}
+
+void rcopy(
+	Bitmap* to,
+	const Bitmap* from,
+	int x,
+	int y,
+	const Rectangle* rect
+) {
+	Rectangle clip;
+	blit_vars(Colour);
+	clip.x = 0;
+	clip.y = 0;
+	clip.w = to->w;
+	clip.h = to->h;
+	blit(
+		from->pixels,
+		to->pixels,
+		to->w,
+		clip,
+		from->w,
+		from->h,
+		*dst = blend(*dst, *src)
+	);
+}
+
+void rcopy_col(
+	Bitmap* to,
+	const Bitmap* from,
+	int x,
+	int y,
+	const Rectangle* rect,
+	Colour colour
+) {
+	Rectangle clip;
+	blit_vars(Colour)
+	clip.x = 0;
+	clip.y = 0;
+	clip.w = to->w;
+	clip.h = to->h;
+	blit(
+		from->pixels,
+		to->pixels,
+		to->w,
+		clip,
+		from->w,
+		from->h,
+		*dst = blend_mod(*dst, *src, colour);
+	);
+}
+
+void rcopy_ac(
+	Bitmap* to,
+	const Bitmap* from,
+	int x,
+	int y,
+	const Rectangle* rect,
+	unsigned char t
+) {
+	Rectangle clip;
+	blit_vars(Colour)
+	clip.x = 0;
+	clip.y = 0;
+	clip.w = to->w;
+	clip.h = to->h;
+	blit(
+		from->pixels,
+		to->pixels,
+		to->w,
+		clip,
+		from->w,
+		from->h,
+		*dst = src->a > t ? *src : *dst;
+	);
+}
+
+void rcopy_rect(
+	Bitmap* to,
+	const Rectangle* rect,
+	Colour colour
+) {
+	Rectangle clip;
+	blit_rect_vars
+	clip.x = 0;
+	clip.y = 0;
+	clip.w = to->w;
+	clip.h = to->h;
+	blit_rect(
+		to->pixels,
+		to->w,
+		clip
+	);
+}