API: moved functions to files to make it easier to import to other projects

2026-03-22 17:24:40 -04:00
parent 05a15d38af
commit 64cf77bbe3
11 changed files with 678 additions and 572 deletions
@@ -0,0 +1,217 @@
+
+
+#include <stdlib.h>
+
+// #include "utils.h"
+#include "filters.h"
+
+unsigned int
+u32_put_alpha(const unsigned int clr, const unsigned char alpha)
+{
+	return (clr & BYTE_RGB) | alpha << SHIFT_24;
+}
+
+unsigned int
+u32_invert(const unsigned int clr)
+{
+	return ((~clr) & BYTE_RGB) | (clr & BYTE_A);
+}
+
+unsigned int
+u32_swap_rb(const unsigned int clr)
+{
+	return (clr & 0xFF00FF00) | ((clr & BYTE_R) >> SHIFT_16) |
+	       ((clr & BYTE_B) << SHIFT_16);
+}
+
+unsigned int
+u32_grayscale(const unsigned int clr)
+{
+	unsigned int red = DECODE_R(clr);
+	unsigned int green = DECODE_G(clr);
+	unsigned int blue = DECODE_B(clr);
+	unsigned int gray =
+	    ((red * 77) + (green * 150) + (blue * 29)) >> SHIFT_8;
+
+	return (clr & BYTE_A) | (gray << SHIFT_16) | (gray << SHIFT_8) | gray;
+}
+
+unsigned int
+u32_step(const unsigned int clr, const unsigned char max)
+{
+	if (DECODE_B(u32_grayscale(clr)) < max)
+	{
+		return ENCODE_ARGB(0, 0, 0, 0);
+	}
+	return ENCODE_ARGB(MAX, MAX, MAX, MAX);
+}
+
+unsigned int
+u32_brighten(const unsigned int clr, const float factor)
+{
+	unsigned int alpha = (clr & BYTE_A);
+	unsigned int red = CLAMP_MAX(DECODE_R(clr) * factor);
+	unsigned int green = CLAMP_MAX(DECODE_G(clr) * factor);
+	unsigned int blue = CLAMP_MAX(DECODE_B(clr) * factor);
+	return (clr & BYTE_A) | (red << SHIFT_16) | (green << SHIFT_8) | blue;
+}
+
+unsigned int
+u32_mix(const unsigned int clr_a, const unsigned int clr_b)
+{
+	unsigned char blue = (DECODE_B(clr_a) + DECODE_B(clr_b)) / 2;
+	unsigned char green = (DECODE_G(clr_a) + DECODE_G(clr_b)) / 2;
+	unsigned char red = (DECODE_R(clr_a) + DECODE_R(clr_b)) / 2;
+
+	return ENCODE_ARGB(DECODE_A(clr_a), red, green, blue);
+}
+
+unsigned int
+u32_lerp(const unsigned clr_a, const unsigned int clr_b, const float ratio)
+{
+	unsigned char blue =
+	    ((DECODE_B(clr_a) * (1 - ratio)) + ((DECODE_B(clr_b) * ratio)));
+	unsigned char green =
+	    ((DECODE_G(clr_a) * (1 - ratio)) + ((DECODE_G(clr_b) * ratio)));
+	unsigned char red =
+	    ((DECODE_R(clr_a) * (1 - ratio)) + ((DECODE_R(clr_b) * ratio)));
+	return ENCODE_ARGB(DECODE_A(clr_a), red, green, blue);
+}
+
+unsigned int
+u32_mask(const unsigned int clr, const char keep)
+{
+	switch (keep)
+	{
+		case 'r':
+			return clr & (BYTE_A | BYTE_R);
+			break;
+		case 'g':
+			return clr & (BYTE_A | BYTE_G);
+			break;
+		case 'b':
+			return clr & (BYTE_A | BYTE_B);
+			break;
+		default:
+			return 0;
+			break;
+	}
+	return 0;
+}
+
+unsigned int
+u32_rotl(const unsigned int clr, const int n)
+{
+	if (n > 8)
+	{
+		return 0;
+	}
+	unsigned int red = DECODE_R(clr);
+	unsigned int green = DECODE_G(clr);
+	unsigned int blue = DECODE_B(clr);
+	red = ((red << n) | (red >> (SHIFT_8 - n))) & BYTE;
+	green = ((green << n) | (green >> (SHIFT_8 - n))) & BYTE;
+	blue = ((blue << n) | (blue >> (SHIFT_8 - n))) & BYTE;
+	return ENCODE_RGB(red, green, blue);
+}
+
+unsigned int
+u32_contrast(const unsigned int clr, const float factor)
+{
+	int red = CLAMP_MIN(CLAMP_MAX(
+	    (int)(factor * (float)(int)(DECODE_R(clr) - HALF_MAX)) + HALF_MAX));
+	int green = CLAMP_MIN(CLAMP_MAX(
+	    (int)(factor * (float)(int)(DECODE_G(clr) - HALF_MAX)) + HALF_MAX));
+	int blue = CLAMP_MIN(CLAMP_MAX(
+	    (int)(factor * (float)(int)(DECODE_B(clr) - HALF_MAX)) + HALF_MAX));
+	return BYTE_A | (red << SHIFT_16) | (green << SHIFT_8) | blue;
+}
+
+unsigned int
+u32_avg_gb(const unsigned int clr)
+{
+	unsigned char red = DECODE_R(clr);
+	unsigned char blue = DECODE_B(clr);
+	unsigned char green = (red + blue) / 2;
+	return ENCODE_RGB(red, green, blue);
+}
+
+unsigned int
+blur_col(const unsigned int* src, const int x, const int y, const PPM* img,
+	 const int radius)
+{
+	unsigned long pt = 0, cnt = 0;
+
+	for (int dx = -radius; dx <= radius; dx++)
+	{
+		int px = x + dx;
+		if (px >= 0 && px < img->width)
+		{
+			pt += u32to_u64(src[y * img->width + px]);
+			cnt++;
+		}
+	}
+
+	if (cnt > 0)
+	{
+		return u64to_u32(pt, cnt);
+	}
+	return src[y * img->width + x];
+}
+
+unsigned int
+blur_row(const unsigned int* src, const int x, const int y, const PPM* img,
+	 const int radius)
+{
+	unsigned long pt = 0, cnt = 0;
+
+	for (int dy = -radius; dy <= radius; dy++)
+	{
+		int py = y + dy;
+		if (py >= 0 && py < img->height)
+		{
+			pt += u32to_u64(src[py * img->width + x]);
+			cnt++;
+		}
+	}
+
+	if (cnt > 0)
+	{
+		return u64to_u32(pt, cnt);
+	}
+	return src[y * img->width + x];
+}
+
+unsigned int*
+box_blur(const unsigned int* src_buf, const PPM* img, const int radius)
+{
+	unsigned int* first_pass = malloc(img->len * sizeof(unsigned int));
+	if (!first_pass)
+	{
+		return 0;
+	}
+	unsigned int* dst_buf = malloc(img->len * sizeof(unsigned int));
+	if (!dst_buf)
+	{
+		free(first_pass);
+		return 0;
+	}
+	for (int y = 0; y < img->height; y++)
+	{
+		for (int x = 0; x < img->width; x++)
+		{
+			first_pass[y * img->width + x] =
+			    blur_col(src_buf, x, y, img, radius);
+		}
+	}
+	for (int y = 0; y < img->height; y++)
+	{
+		for (int x = 0; x < img->width; x++)
+		{
+			dst_buf[y * img->width + x] =
+			    blur_row(first_pass, x, y, img, radius);
+		}
+	}
+	free(first_pass);
+	return dst_buf;
+}