From c124c9fccad63c0699111e99b5792b41ee08ffaa Mon Sep 17 00:00:00 2001
From: Allanis <allanis@saracraft.net>
Date: Fri, 1 Feb 2013 23:12:07 +0000
Subject: [PATCH] [Change] Stars use alpha instead of colors.
---
src/space.c | 61 ++++++++++++++++++++++++++++-------------------------
1 file changed, 32 insertions(+), 29 deletions(-)
diff --git a/src/space.c b/src/space.c
index 437ce81..170ee0c 100644
--- a/src/space.c
+++ b/src/space.c
@@ -12,34 +12,37 @@ static Vec2 starPos[STAR_LAYERS];
static gl_texture* starBG_create(const int density);
static void put_pixel(SDL_Surface* surface, const int x, const int y,
- const Uint8 R, const Uint8 G, const Uint8 B);
+ const Uint8 R, const Uint8 G, const Uint8 B, const Uint8 A);
// Modify the pixel at (x,y) of the surface to be of color RGB.
-static void put_pixel(SDL_Surface* surface, const int x, const int y, const Uint8 R, const Uint8 G, const Uint8 B) {
- Uint32 color = SDL_MapRGB(surface->format, R, G, B);
+static void put_pixel(SDL_Surface* surface, const int x, const int y,
+ const Uint8 R, const Uint8 G, const Uint8 B, const Uint8 A) {
+
+ Uint32 pixel = SDL_MapRGBA(surface->format, R, G, B, A);
+ int bpp = surface->format->BytesPerPixel;
+ // p is the address to the pixel we want to set.
+ Uint8* p = (Uint8*)surface->pixels + y * surface->pitch + x * bpp;
- Uint8* bufp8;
- Uint16* bufp16;
- Uint32* bufp32;
-
- switch(surface->format->BytesPerPixel) {
- case 1: // 8bpp.
- bufp8 = (Uint8)surface->pixels + y*surface->pitch + x;
- *bufp8 = color;
+ switch(bpp) {
+ case 1:
+ *p = pixel;
break;
- case 2: // 15 or 16bpp.
- bufp16 = (Uint16*)surface->pixels + y*surface->pitch/2 + x;
- *bufp16 = color;
+ case 2:
+ *(Uint16*)p = pixel;
break;
- case 3: // 24bpp, Slow as hell.
- bufp8 = (Uint8*)surface->pixels + y*surface->pitch + x;
- *(bufp8 + surface->format->Rshift/8) = R;
- *(bufp8 + surface->format->Gshift/8) = G;
- *(bufp8 + surface->format->Bshift/8) = B;
+ case 3:
+ if(SDL_BYTEORDER == SDL_BIG_ENDIAN) {
+ p[0] = (pixel >> 16) & 0xff;
+ p[1] = (pixel >> 8) & 0xff;
+ p[2] = pixel & 0xff;
+ } else {
+ p[0] = pixel & 0xff;
+ p[1] = (pixel >> 8) & 0xff;
+ p[2] = (pixel >> 16) & 0xff;
+ }
break;
- case 4: // 32bpp.
- bufp32 = (Uint32*)surface->pixels + y*surface->pitch/4 + x;
- *bufp32 = color;
+ case 4:
+ *(Uint32*)p = pixel;
break;
}
}
@@ -49,7 +52,7 @@ static void put_pixel(SDL_Surface* surface, const int x, const int y, const Uint
static gl_texture* starBG_create(const int density) {
SDL_Surface* surface;
int w, h;
- int i, b, d, x, y;
+ int i, d;
w = (int)((float)gl_screen.w * 1.5);
if((w & (w-1)) != 0) {
@@ -72,13 +75,13 @@ static gl_texture* starBG_create(const int density) {
return NULL;
}
+ SDL_LockSurface(surface);
+
d = (int)((FP)(density)*(FP)(gl_screen.w)*(FP)(gl_screen.h)/1000./1000.);
- for(i = 0; i < d; i++) {
- b = RNG(50, 255);
- x = RNG(0, w-1);
- y = RNG(0, h-1);
- put_pixel(surface, x, y, b, b, b);
- }
+ for(i = 0; i < d; i++)
+ put_pixel(surface, RNG(0,w-1), RNG(0,h-1), 255, 255, 255, RNG(50, 255));
+
+ SDL_UnlockSurface(surface);
return gl_loadImage(surface);
}