diff options
Diffstat (limited to 'pixman/pixman-gradient-walker.c')
| -rw-r--r-- | pixman/pixman-gradient-walker.c | 118 |
1 files changed, 90 insertions, 28 deletions
diff --git a/pixman/pixman-gradient-walker.c b/pixman/pixman-gradient-walker.c index 5944a55..b31d5ad 100644 --- a/pixman/pixman-gradient-walker.c +++ b/pixman/pixman-gradient-walker.c @@ -24,7 +24,7 @@ */ #ifdef HAVE_CONFIG_H -#include <config.h> +#include <pixman-config.h> #endif #include "pixman-private.h" @@ -54,7 +54,7 @@ static void gradient_walker_reset (pixman_gradient_walker_t *walker, pixman_fixed_48_16_t pos) { - int32_t x, left_x, right_x; + int64_t x, left_x, right_x; pixman_color_t *left_c, *right_c; int n, count = walker->num_stops; pixman_gradient_stop_t *stops = walker->stops; @@ -122,10 +122,9 @@ gradient_walker_reset (pixman_gradient_walker_t *walker, left_c = right_c; } - /* The alpha channel is scaled to be in the [0, 255] interval, - * and the red/green/blue channels are scaled to be in [0, 1]. + /* The alpha/red/green/blue channels are scaled to be in [0, 1]. * This ensures that after premultiplication all channels will - * be in the [0, 255] interval. + * be in the [0, 1] interval. */ la = (left_c->alpha * (1.0f/257.0f)); lr = (left_c->red * (1.0f/257.0f)); @@ -143,7 +142,7 @@ gradient_walker_reset (pixman_gradient_walker_t *walker, if (FLOAT_IS_ZERO (rx - lx) || left_x == INT32_MIN || right_x == INT32_MAX) { walker->a_s = walker->r_s = walker->g_s = walker->b_s = 0.0f; - walker->a_b = (la + ra) / 2.0f; + walker->a_b = (la + ra) / 510.0f; walker->r_b = (lr + rr) / 510.0f; walker->g_b = (lg + rg) / 510.0f; walker->b_b = (lb + rb) / 510.0f; @@ -152,12 +151,12 @@ gradient_walker_reset (pixman_gradient_walker_t *walker, { float w_rec = 1.0f / (rx - lx); - walker->a_b = (la * rx - ra * lx) * w_rec; + walker->a_b = (la * rx - ra * lx) * w_rec * (1.0f/255.0f); walker->r_b = (lr * rx - rr * lx) * w_rec * (1.0f/255.0f); walker->g_b = (lg * rx - rg * lx) * w_rec * (1.0f/255.0f); walker->b_b = (lb * rx - rb * lx) * w_rec * (1.0f/255.0f); - walker->a_s = (ra - la) * w_rec; + walker->a_s = (ra - la) * w_rec * (1.0f/255.0f); walker->r_s = (rr - lr) * w_rec * (1.0f/255.0f); walker->g_s = (rg - lg) * w_rec * (1.0f/255.0f); walker->b_s = (rb - lb) * w_rec * (1.0f/255.0f); @@ -169,34 +168,97 @@ gradient_walker_reset (pixman_gradient_walker_t *walker, walker->need_reset = FALSE; } -uint32_t -_pixman_gradient_walker_pixel (pixman_gradient_walker_t *walker, - pixman_fixed_48_16_t x) +static argb_t +pixman_gradient_walker_pixel_float (pixman_gradient_walker_t *walker, + pixman_fixed_48_16_t x) { - float a, r, g, b; - uint8_t a8, r8, g8, b8; - uint32_t v; + argb_t f; float y; if (walker->need_reset || x < walker->left_x || x >= walker->right_x) - gradient_walker_reset (walker, x); + gradient_walker_reset (walker, x); y = x * (1.0f / 65536.0f); - a = walker->a_s * y + walker->a_b; - r = a * (walker->r_s * y + walker->r_b); - g = a * (walker->g_s * y + walker->g_b); - b = a * (walker->b_s * y + walker->b_b); + f.a = walker->a_s * y + walker->a_b; + f.r = f.a * (walker->r_s * y + walker->r_b); + f.g = f.a * (walker->g_s * y + walker->g_b); + f.b = f.a * (walker->b_s * y + walker->b_b); - a8 = a + 0.5f; - r8 = r + 0.5f; - g8 = g + 0.5f; - b8 = b + 0.5f; + return f; +} + +static uint32_t +pixman_gradient_walker_pixel_32 (pixman_gradient_walker_t *walker, + pixman_fixed_48_16_t x) +{ + argb_t f; + float y; + + if (walker->need_reset || x < walker->left_x || x >= walker->right_x) + gradient_walker_reset (walker, x); + + y = x * (1.0f / 65536.0f); + + /* Instead of [0...1] for ARGB, we want [0...255], + * multiply alpha with 255 and the color channels + * also get multiplied by the alpha multiplier. + * + * We don't use pixman_contract_from_float because it causes a 2x + * slowdown to do so, and the values are already normalized, + * so we don't have to worry about values < 0.f or > 1.f + */ + f.a = 255.f * (walker->a_s * y + walker->a_b); + f.r = f.a * (walker->r_s * y + walker->r_b); + f.g = f.a * (walker->g_s * y + walker->g_b); + f.b = f.a * (walker->b_s * y + walker->b_b); - v = ((a8 << 24) & 0xff000000) | - ((r8 << 16) & 0x00ff0000) | - ((g8 << 8) & 0x0000ff00) | - ((b8 >> 0) & 0x000000ff); + return (((uint32_t)(f.a + .5f) << 24) & 0xff000000) | + (((uint32_t)(f.r + .5f) << 16) & 0x00ff0000) | + (((uint32_t)(f.g + .5f) << 8) & 0x0000ff00) | + (((uint32_t)(f.b + .5f) >> 0) & 0x000000ff); +} + +void +_pixman_gradient_walker_write_narrow (pixman_gradient_walker_t *walker, + pixman_fixed_48_16_t x, + uint32_t *buffer) +{ + *buffer = pixman_gradient_walker_pixel_32 (walker, x); +} + +void +_pixman_gradient_walker_write_wide (pixman_gradient_walker_t *walker, + pixman_fixed_48_16_t x, + uint32_t *buffer) +{ + *(argb_t *)buffer = pixman_gradient_walker_pixel_float (walker, x); +} + +void +_pixman_gradient_walker_fill_narrow (pixman_gradient_walker_t *walker, + pixman_fixed_48_16_t x, + uint32_t *buffer, + uint32_t *end) +{ + register uint32_t color; + + color = pixman_gradient_walker_pixel_32 (walker, x); + while (buffer < end) + *buffer++ = color; +} + +void +_pixman_gradient_walker_fill_wide (pixman_gradient_walker_t *walker, + pixman_fixed_48_16_t x, + uint32_t *buffer, + uint32_t *end) +{ + register argb_t color; + argb_t *buffer_wide = (argb_t *)buffer; + argb_t *end_wide = (argb_t *)end; - return v; + color = pixman_gradient_walker_pixel_float (walker, x); + while (buffer_wide < end_wide) + *buffer_wide++ = color; } |