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Skip transparent pixels when possible in most of rendering functions,
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because they often work on "sparse" sprites or hex (25% transparent)
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@alinkmaze
alinkmaze committed Apr 29, 2008
1 parent a099348 commit b4d40ef
Showing 1 changed file with 98 additions and 85 deletions.
183 changes: 98 additions & 85 deletions src/sdl_utils.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -509,9 +509,9 @@ surface scale_surface_blended(surface const &surf, int w, int h)
return create_optimized_surface(dst);
}

surface adjust_surface_colour(surface const &surf, int r, int g, int b)
surface adjust_surface_colour(surface const &surf, int red, int green, int blue)
{
if((r == 0 && g == 0 && b == 0) || surf == NULL)
if((red == 0 && green == 0 && blue == 0) || surf == NULL)
return create_optimized_surface(surf);

surface nsurf(make_neutral_surface(surf));
Expand All @@ -527,18 +527,20 @@ surface adjust_surface_colour(surface const &surf, int r, int g, int b)
Uint32* end = beg + nsurf->w*surf->h;

while(beg != end) {
Uint8 red, green, blue, alpha;
alpha = (*beg) >> 24;
red = (*beg) >> 16;
green = (*beg) >> 8;
blue = (*beg) >> 0;
Uint8 alpha = (*beg) >> 24;

if(alpha) {
Uint8 r, g, b;
r = (*beg) >> 16;
g = (*beg) >> 8;
b = (*beg) >> 0;

red = maximum<int>(0,minimum<int>(255,int(red)+r));
green = maximum<int>(0,minimum<int>(255,int(green)+g));
blue = maximum<int>(0,minimum<int>(255,int(blue)+b));
r = maximum<int>(0,minimum<int>(255,int(r)+red));
g = maximum<int>(0,minimum<int>(255,int(g)+green));
b = maximum<int>(0,minimum<int>(255,int(b)+blue));

*beg = (alpha << 24) + (red << 16) + (green << 8) + blue;
*beg = (alpha << 24) + (r << 16) + (g << 8) + b;
}

++beg;
}
Expand All @@ -564,24 +566,26 @@ surface greyscale_image(surface const &surf)
Uint32* end = beg + nsurf->w*surf->h;

while(beg != end) {
Uint8 r, g, b, a;
a = (*beg) >> 24;
r = (*beg) >> 16;
g = (*beg) >> 8;
b = (*beg);

//const Uint8 avg = (red+green+blue)/3;

// Use the correct formula for RGB to grayscale conversion.
// Ok, this is no big deal :)
// The correct formula being:
// gray=0.299red+0.587green+0.114blue
const Uint8 avg = static_cast<Uint8>((
77 * static_cast<Uint16>(r) +
150 * static_cast<Uint16>(g) +
29 * static_cast<Uint16>(b) ) / 256);
Uint8 alpha = (*beg) >> 24;

*beg = (a << 24) | (avg << 16) | (avg << 8) | avg;
if(alpha) {
Uint8 r, g, b;
r = (*beg) >> 16;
g = (*beg) >> 8;
b = (*beg);
//const Uint8 avg = (red+green+blue)/3;

// Use the correct formula for RGB to grayscale conversion.
// Ok, this is no big deal :)
// The correct formula being:
// gray=0.299red+0.587green+0.114blue
const Uint8 avg = static_cast<Uint8>((
77 * static_cast<Uint16>(r) +
150 * static_cast<Uint16>(g) +
29 * static_cast<Uint16>(b) ) / 256);

*beg = (alpha << 24) | (avg << 16) | (avg << 8) | avg;
}

++beg;
}
Expand All @@ -607,29 +611,31 @@ surface darken_image(surface const &surf)
Uint32* end = beg + nsurf->w*surf->h;

while(beg != end) {
Uint8 r, g, b, a;
a = (*beg) >> 24;
r = (*beg) >> 16;
g = (*beg) >> 8;
b = (*beg);

//const Uint8 avg = (red+green+blue)/3;

// Use the correct formula for RGB to grayscale conversion.
// Ok, this is no big deal :)
// The correct formula being:
// gray=0.299red+0.587green+0.114blue
const Uint8 avg = static_cast<Uint8>((
77 * static_cast<Uint16>(r) +
150 * static_cast<Uint16>(g) +
29 * static_cast<Uint16>(b) ) / 256);
// then tint 77%, 67%, 72%
r = ((avg * 196) >> 8);
g = ((avg * 171) >> 8);
b = ((avg * 184) >> 8);

Uint8 alpha = (*beg) >> 24;

*beg = (a << 24) | (r << 16) | (g << 8) | b;
if(alpha) {
Uint8 r, g, b;
r = (*beg) >> 16;
g = (*beg) >> 8;
b = (*beg);

//const Uint8 avg = (red+green+blue)/3;

// Use the correct formula for RGB to grayscale conversion.
// Ok, this is no big deal :)
// The correct formula being:
// gray=0.299red+0.587green+0.114blue
const Uint8 avg = static_cast<Uint8>((
77 * static_cast<Uint16>(r) +
150 * static_cast<Uint16>(g) +
29 * static_cast<Uint16>(b) ) / 256);
// then tint 77%, 67%, 72%
r = ((avg * 196) >> 8);
g = ((avg * 171) >> 8);
b = ((avg * 184) >> 8);

*beg = (alpha << 24) | (r << 16) | (g << 8) | b;
}

++beg;
}
Expand Down Expand Up @@ -693,17 +699,20 @@ surface brighten_image(surface const &surf, fixed_t amount)

if (amount < 0) amount = 0;
while(beg != end) {
Uint8 red, green, blue, alpha;
alpha = (*beg) >> 24;
red = (*beg) >> 16;
green = (*beg) >> 8;
blue = (*beg) >> 0;
Uint8 alpha = (*beg) >> 24;

red = minimum<unsigned>(unsigned(fxpmult(red,amount)),255);
green = minimum<unsigned>(unsigned(fxpmult(green,amount)),255);
blue = minimum<unsigned>(unsigned(fxpmult(blue,amount)),255);
if(alpha) {
Uint8 r, g, b;
r = (*beg) >> 16;
g = (*beg) >> 8;
b = (*beg);

*beg = (alpha << 24) + (red << 16) + (green << 8) + blue;
r = minimum<unsigned>(unsigned(fxpmult(r, amount)),255);
g = minimum<unsigned>(unsigned(fxpmult(g, amount)),255);
b = minimum<unsigned>(unsigned(fxpmult(b, amount)),255);

*beg = (alpha << 24) + (r << 16) + (g << 8) + b;
}

++beg;
}
Expand Down Expand Up @@ -732,15 +741,17 @@ surface adjust_surface_alpha(surface const &surf, fixed_t amount, bool optimize)

if (amount < 0) amount = 0;
while(beg != end) {
Uint8 red, green, blue, alpha;
alpha = (*beg) >> 24;
red = (*beg) >> 16;
green = (*beg) >> 8;
blue = (*beg) >> 0;
Uint8 alpha = (*beg) >> 24;

alpha = minimum<unsigned>(unsigned(fxpmult(alpha,amount)),255);
if(alpha) {
Uint8 r, g, b;
r = (*beg) >> 16;
g = (*beg) >> 8;
b = (*beg);

*beg = (alpha << 24) + (red << 16) + (green << 8) + blue;
alpha = minimum<unsigned>(unsigned(fxpmult(alpha,amount)),255);
*beg = (alpha << 24) + (r << 16) + (g << 8) + b;
}

++beg;
}
Expand Down Expand Up @@ -772,15 +783,17 @@ surface adjust_surface_alpha_add(surface const &surf, int amount, bool optimize)
Uint32* end = beg + nsurf->w*surf->h;

while(beg != end) {
Uint8 red, green, blue, alpha;
alpha = (*beg) >> 24;
red = (*beg) >> 16;
green = (*beg) >> 8;
blue = (*beg) >> 0;

alpha = Uint8(maximum<int>(0,minimum<int>(255,int(alpha) + amount)));
Uint8 alpha = (*beg) >> 24;

*beg = (alpha << 24) + (red << 16) + (green << 8) + blue;
if(alpha) {
Uint8 r, g, b;
r = (*beg) >> 16;
g = (*beg) >> 8;
b = (*beg);

alpha = Uint8(maximum<int>(0,minimum<int>(255,int(alpha) + amount)));
*beg = (alpha << 24) + (r << 16) + (g << 8) + b;
}

++beg;
}
Expand Down Expand Up @@ -823,20 +836,20 @@ surface mask_surface(surface const &surf, surface const &mask)
Uint32* mend = mbeg + nmask->w*nmask->h;

while(beg != end && mbeg != mend) {
Uint8 red, green, blue, alpha;
Uint8 malpha;

alpha = (*beg) >> 24;
red = (*beg) >> 16;
green = (*beg) >> 8;
blue = (*beg) >> 0;

malpha = (*mbeg) >> 24;
Uint8 alpha = (*beg) >> 24;

alpha = Uint8(minimum<int>(malpha, alpha));
if(alpha) {
Uint8 r, g, b;
r = (*beg) >> 16;
g = (*beg) >> 8;
b = (*beg);

*beg = (alpha << 24) + (red << 16) + (green << 8) + blue;
Uint8 malpha = (*mbeg) >> 24;
if (alpha > malpha) alpha = malpha;

*beg = (alpha << 24) + (r << 16) + (g << 8) + b;
}

++beg;
++mbeg;
}
Expand Down

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