1 files changed, 177 insertions, 0 deletions
diff --git a/render.c b/render.c
new file mode 100644
index 0000000..578abef
--- /dev/null
+++ b/render.c
@@ -0,0 +1,177 @@
+#include "render.h"
+
+static struct {
+	Colour pixels[renderer_w * renderer_h];
+} 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 init_renderer() {
+}
+
+void renderer_begin_frame() {
+	int i;
+
+	for (i = 0; i < renderer_w * renderer_h; i++) {
+		renderer.pixels[i] = make_black();
+	}
+}
+
+Colour* get_render_pixels() {
+	return renderer.pixels;
+}
+
+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;
+}
+
+void init_font(
+	BM_Font* font,
+	Bitmap* bmp,
+	int char_w,
+	int char_h,
+	int chars_across
+) {
+	font->bmp = bmp;
+	font->char_w = char_w;
+	font->char_h = char_h;
+	font->chars_across = chars_across;
+}
+
+void rfont_char(int x, int y, char c) {
+
+}
+
+void rfont_char_col(int x, int y, char c, Colour colour) {
+
+}
+
+void rfont_text(
+	int x,
+	int y,
+	const char* text
+) {
+}
+
+void rfont_text_col(
+	int x,
+	int y,
+	const char* text,
+	Colour colour
+) {
+
+}
+
+void render_bitmap(
+	const Bitmap* bitmap,
+	int x,
+	int y,
+	const Rectangle* rect
+) {
+	int i, j, stride, sstride, n;
+	Colour* dst;
+	const Colour* src;
+	Rectangle sub;
+
+	sub = *rect;
+
+	if (sub.w <= 0) { return; }
+	if (sub.h <= 0) { return; }
+	if (sub.w > bitmap->w) { return; }
+	if (sub.h > bitmap->h) { return; }
+
+	if ((n = -x) > 0) {
+		sub.w -= n;
+		sub.x += n;
+		x += n;
+	}
+	
+	if ((n = -y) > 0) {
+		sub.h -= n;
+		sub.y += n;
+		y += n;
+	}
+	
+	if ((n = x + sub.w - renderer_w) > 0) {
+		sub.w -= n;
+	}
+
+	if ((n = y + sub.h - renderer_h) > 0) {
+		sub.h -= n;
+	}
+
+	if (sub.w <= 0) { return; }
+	if (sub.h <= 0) { return; }
+
+	dst = renderer.pixels + (x + y * renderer_w);
+	src = bitmap->pixels + (sub.x + sub.y * bitmap->w);
+
+	stride = renderer_w - sub.w;
+	sstride = bitmap->w - sub.w;
+
+	for (i = 0; i < sub.h; i++) {
+		for (j = 0; j < sub.w; j++) {
+			*dst = blend(*dst, *src);
+			dst++;
+			src++;
+		}
+		dst += stride;
+		src += sstride;
+	}
+}
+
+void render_bitmap_col(
+	const Bitmap* bitmap,
+	int x,
+	int y,
+	const Rectangle* rect,
+	Colour colour
+) {
+
+}