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Remove alpha-blending framebuffer functions

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This commit is contained in:
Josh Holtrop 2023-09-13 10:57:45 -04:00
parent 3d911ab191
commit c958b9ffcc
1 changed files with 0 additions and 79 deletions
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79
src/hulk/fb.d
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@ -131,70 +131,6 @@ struct Fb
} }
} }
/**
* Draw a character.
*
* @param x X coordinate of left side of character.
* @param y Y coordinate of bottom side of character.
* @param ch Character to draw.
* @param color Color of character.
*/
static void character(int x, int y, char ch, uint color)
{
const(CharInfo) * ci = &Kfont.chars[ch];
blend_alpha_bitmap(x + ci.left, y + Kfont.baseline_offset + ci.top - ci.height, ci.bitmap, ci.width, ci.height, color);
}
/**
* Blend an 8-bit alpha bitmap to the framebuffer.
*
* @param x X coordinate of left side of target location.
* @param y Y coordinate of bottom side of target location.
* @param alpha_bitmap 8-bit alpha-channel bitmap.
* @param width Bitmap width.
* @param height Bitmap height.
* @param color Color to blend with alpha value.
*/
static void blend_alpha_bitmap(size_t x, size_t y, const(ubyte) * alpha_bitmap,
size_t width, size_t height, uint color)
{
y += height - 1u;
size_t bitmap_index;
for (size_t iy = 0u; iy < height; iy++)
{
size_t row_buffer_index = buffer_index(x, y);
for (size_t ix = 0u; ix < width; ix++)
{
size_t buffer_index = row_buffer_index + ix;
ubyte alpha = alpha_bitmap[bitmap_index];
uint current_color = m_buffer1[buffer_index];
uint in_color_scaled = scale_color(color, alpha);
uint old_color_scaled = scale_color(current_color, 255u - alpha);
uint new_color = old_color_scaled + in_color_scaled;
m_buffer1[buffer_index] = new_color;
bitmap_index++;
}
memcpy32(&m_device_buffer[row_buffer_index], &m_buffer1[row_buffer_index], width);
y--;
}
}
/**
* Blend an 8-bit alpha bitmap to the framebuffer.
*
* @param x X coordinate of left side of target location.
* @param y Y coordinate of bottom side of target location.
* @param alpha_bitmap 8-bit alpha-channel bitmap.
* @param width Bitmap width.
* @param height Bitmap height.
* @param color Color to blend with alpha value.
*/
static void blend_alpha_bitmap(size_t x, size_t y, const(ubyte)[] alpha_bitmap,
size_t width, size_t height, uint color)
{
blend_alpha_bitmap(x, y, alpha_bitmap.ptr, width, height, color);
}
/** /**
* Blit an 8-bit alpha bitmap to the framebuffer. * Blit an 8-bit alpha bitmap to the framebuffer.
* The foreground will be white (based on the alpha value), and the * The foreground will be white (based on the alpha value), and the
@ -262,21 +198,6 @@ struct Fb
(m_stride * height)); (m_stride * height));
} }
/**
* Scale a color value by an alpha amount.
*
* @param color Color value.
* @param alpha Alpha amount.
*
* @return Scaled color value.
*/
private static uint scale_color(uint color, ubyte alpha)
{
return ((((color & 0xFFu) * alpha) >> 8u) & 0xFFu) |
((((color & 0xFF00u) * alpha) >> 8u) & 0xFF00u) |
((((color & 0xFF0000u) * alpha) >> 8u) & 0xFF0000u);
}
/** /**
* Return the buffer index for the given X and Y coordinates. * Return the buffer index for the given X and Y coordinates.
* *