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Difference between revisions of "API-Truecolor"
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→Example: a few more comments and a minor formatting correction
(→Example: a few more comments and a minor formatting correction) |
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| Line 97: | Line 97: | ||
uint32 t = 0; | uint32 t = 0; | ||
// Create a mask to limit the color from exceeding the bitdepth | |||
// The result is equivalent to: | |||
// uint32 mask = 0; | |||
// for (int i = format.bytesPerPixel; i > 0; i--) { | |||
// mask <<= 8; | |||
// mask |= 0xFF; | |||
// } | |||
uint32 mask = (1 << (format.bytesPerPixel << 3)) - 1; | uint32 mask = (1 << (format.bytesPerPixel << 3)) - 1; | ||
// Repeat this until the event manager tells us to stop | |||
while (!shouldQuit()) { | while (!shouldQuit()) { | ||
// Keep t from exceeding the number of bits in each pixel. | |||
// I think this is faster than "t %= (format.bytesPerPixel * 8);" would be. | |||
t &= (format.bytesPerPixel << 3) - 1; | |||
// Draw the actual gradient | // Draw the actual gradient | ||
| Line 105: | Line 119: | ||
for (int16 x = 0; x < 640; x++) { | for (int16 x = 0; x < 640; x++) { | ||
uint32 color = (x * y) & mask; | uint32 color = (x * y) & mask; | ||
color = (color << t) | (color >> ((format.bytesPerPixel << 3) - t)); | color = (color << t) | (color >> ((format.bytesPerPixel << 3) - t)); | ||
| Line 114: | Line 127: | ||
#ifdef SCUMM_BIG_ENDIAN | #ifdef SCUMM_BIG_ENDIAN | ||
for (int i = 0; i < format.bytesPerPixel; i++) | for (int i = 0; i < format.bytesPerPixel; i++) { | ||
dst[format.bytesPerPixel - i] = color & 0xFF; | dst[format.bytesPerPixel - i] = color & 0xFF; | ||
color >>= 8; | color >>= 8; | ||
| Line 128: | Line 140: | ||
} | } | ||
} | } | ||
// Copy our gradient to the screen. The pitch of our image is the width * the number of bytes per pixel. | |||
_system->copyRectToScreen(offscreenBuffer, 640 * format.bytesPerPixel, 0, 0, 640, 480); | _system->copyRectToScreen(offscreenBuffer, 640 * format.bytesPerPixel, 0, 0, 640, 480); | ||
// Tell the system to update the screen. | |||
_system->updateScreen(); | _system->updateScreen(); | ||
// Get new events from the event manager so the window doesn't appear non-responsive. | |||
parseEvents(); | parseEvents(); | ||
// Wait a semi-arbitrary length in order to animate fluidly, but not insanely fast | // Wait a semi-arbitrary length in order to animate fluidly, but not insanely fast | ||
_system->delayMillis(66); | _system->delayMillis(66); | ||
// Increment our time variable, which doubles as our bit-shift counter. | |||
t++; | t++; | ||
} | } | ||