color management

render/gles2/color.c

@@ -0,0 +1,241 @@
+// OpenGL Color conversion
+
+#define _XOPEN_SOURCE 500 // for strdup
+
+#include <GLES3/gl32.h>
+
+#include <assert.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <time.h>
+
+#include <wlr/types/wlr_list.h>
+#include <wlr/render/color.h>
+
+#include <lcms2.h>
+
+#include "render/gles2.h"
+
+// GL3+ or GL_EXT_texture_norm16 on ES 3.2
+#define GL_RGBA16 0x805B
+
+struct lut {
+	GLuint tex_id;
+	struct wlr_color_config *input, *output;
+	cmsHTRANSFORM transform;
+};
+
+#define LUTS_MAX 100
+
+static struct wlr_list luts;
+
+static int color_compare(void *av, void *bv) {
+	struct wlr_color_config *a = av, *b = bv;
+	if(a == b)
+		return 0;
+	if(!a)
+		return 1;
+	if(!b)
+		return -1;
+
+	return strcmp(a->icc_profile_path, b->icc_profile_path);
+}
+
+struct wlr_color_config *wlr_color_config_copy(struct wlr_color_config *value) {
+	if(! value)
+		return NULL;
+
+	struct wlr_color_config *copy = calloc(1, sizeof(*copy));
+	copy->icc_profile_path = strdup(value->icc_profile_path);
+	return copy;
+}
+
+static cmsHPROFILE color_load(struct wlr_color_config *color) {
+	if(color) {
+		cmsHPROFILE pro = cmsOpenProfileFromFile (color->icc_profile_path, "r");
+		if (pro == NULL) {
+			wlr_log(WLR_ERROR, "error loading icc profile %s", color->icc_profile_path);
+		} else {
+			return pro;
+		}
+	}
+	return cmsCreate_sRGBProfile();
+
+}
+
+static const char *color_describe(struct wlr_color_config *color) {
+	if(! color)
+		return "sRGB";
+
+	char *base = strrchr(color->icc_profile_path, '/');
+	return base ? base + 1 : color->icc_profile_path;
+}
+
+struct wlr_color_config *wlr_color_config_load(const char *icc_profile_path) {
+	assert(icc_profile_path);
+
+	if(0 == strlen(icc_profile_path)) {
+		return NULL;
+	}
+
+	bool can_access = access(icc_profile_path, F_OK) != -1;
+	if (!can_access) {
+		wlr_log(WLR_ERROR, "Unable to access color profile '%s'", icc_profile_path);
+		return NULL;
+	}
+
+	struct wlr_color_config *color = calloc(1, sizeof(*color));
+	color->icc_profile_path = strdup(icc_profile_path);
+	return color;
+}
+
+void wlr_color_config_free(struct wlr_color_config *color) {
+	if(! color)
+		return;
+	free(color->icc_profile_path);
+	free(color);
+}
+
+static struct lut *load_lut(struct wlr_color_config *input, struct wlr_color_config *output) {
+	if(0 == color_compare(input, output))
+		return NULL;
+
+	struct lut *lut;
+
+	// find an existing cached lut
+	for (size_t i = 0; i < luts.length; i++) {
+		lut = luts.items[i];
+		if(color_compare(lut->input, input) || color_compare(lut->output, output))
+			continue;
+
+		// move to head to list
+		if(i > 5) {
+			wlr_list_del(&luts, i);
+			wlr_list_insert(&luts, 0, lut);
+		}
+		return lut;
+	}
+
+	// clean an old LUT to avoid memory leak
+	if(luts.length > LUTS_MAX) {
+		struct lut *lut = wlr_list_pop(&luts);
+		wlr_log(WLR_DEBUG, "destroy CLUT %s -> %s", color_describe(lut->input), color_describe(lut->output));
+		wlr_color_config_free(lut->input);
+		wlr_color_config_free(lut->output);
+		cmsDeleteTransform(lut->transform);
+		glDeleteTextures(1, &lut->tex_id);
+		free(lut);
+	}
+
+	wlr_log(WLR_INFO, "create CLUT %s -> %s", color_describe(input), color_describe(output));
+	cmsHPROFILE inp = color_load(input);
+	cmsHPROFILE outp = color_load(output);
+
+	// According to lcms docs, black point compensation does not apply to perceptual intent, so we omit the flag.
+	cmsHTRANSFORM xform = cmsCreateTransform(
+			inp, TYPE_RGB_16,
+			outp, TYPE_RGB_16,
+			INTENT_PERCEPTUAL,
+			cmsFLAGS_HIGHRESPRECALC | cmsFLAGS_NOCACHE);
+
+	cmsCloseProfile(inp);
+	cmsCloseProfile(outp);
+
+	if (xform == NULL) {
+		wlr_log(WLR_ERROR, "failed to create color transform");
+		return NULL;
+	}
+
+	// save the new LUT
+	lut = malloc(sizeof(*lut));
+	*lut = (struct lut){
+		.input = wlr_color_config_copy(input),
+			.output = wlr_color_config_copy(output),
+			.transform = xform,
+	};
+	wlr_list_insert(&luts, 0, lut);
+	return lut;
+}
+
+void color_convert(struct wlr_color_config *ic, struct wlr_color_config *oc, const float input[static 4], float output[static 4]) {
+	struct lut *lut = load_lut(ic, oc);
+	if(! lut) {
+		memcpy(output, input, 4 * sizeof(float));
+		return;
+	}
+
+	uint16_t out[3], in[3] = {
+		input[0] * UINT16_MAX,
+		input[1] * UINT16_MAX,
+		input[2] * UINT16_MAX,
+	};
+	cmsDoTransform(lut->transform, in, out, 1);
+	output[0] = (float)out[0] / UINT16_MAX;
+	output[1] = (float)out[1] / UINT16_MAX;
+	output[2] = (float)out[2] / UINT16_MAX;
+	output[3] = input[3];
+}
+
+GLuint color_build_lut(struct wlr_color_config *input, struct wlr_color_config *output) {
+	struct lut *lut = load_lut(input, output);
+	if(! lut)
+		return 0;
+
+	if(lut->tex_id)
+		return lut->tex_id;
+
+	// 3D array: [B][G][R] = [R,G,B,A]
+	// Notes:
+	// - The first dimension is blue
+	// - The alpha channel is unused but needed since GL_RGB16 does not work.
+	uint16_t table[COLOR_LUT_SIZE][COLOR_LUT_SIZE][COLOR_LUT_SIZE][4];
+
+	int n = COLOR_LUT_SIZE;
+	int r, g, b;
+	for (r = 0; r < n; r++) {
+		for (g = 0; g < n; g++) {
+			for (b = 0; b < n; b++) {
+				uint16_t in[3];
+				in[0] = floor((double) r / (n - 1) * UINT16_MAX + 0.5);
+				in[1] = floor((double) g / (n - 1) * UINT16_MAX + 0.5);
+				in[2] = floor((double) b / (n - 1) * UINT16_MAX + 0.5);
+
+				cmsDoTransform(lut->transform, in, table[b][g][r], 1);
+			}
+		}
+	}
+
+	glGenTextures (1, &lut->tex_id);
+	glActiveTexture(GL_TEXTURE1);
+	glBindTexture(GL_TEXTURE_3D, lut->tex_id);
+
+	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);
+	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_WRAP_R, GL_CLAMP_TO_EDGE);
+
+	// we must use linear interpolation for small LUTs
+	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
+	glTexParameteri(GL_TEXTURE_3D, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
+
+	glTexImage3D(GL_TEXTURE_3D, 0, GL_RGBA16, n, n, n,
+			0, GL_RGBA, GL_UNSIGNED_SHORT, table);
+
+	// cleanup
+	glBindTexture(GL_TEXTURE_3D, 0);
+	glActiveTexture(GL_TEXTURE0);
+
+	return lut->tex_id;
+}
+
+static void lcms_error_handler(cmsContext ctx, cmsUInt32Number code, const char *msg) {
+	wlr_log(WLR_ERROR, "color management: [%i] %s", code, msg);
+}
+
+void color_engine_setup(void) {
+	wlr_list_init(&luts);
+	cmsSetLogErrorHandler(lcms_error_handler);
+}
+