add a gradient generator

Lib/Makefile

@@ -67,6 +67,7 @@ filtres.o:	filtres.c	$(DEPS)
 
 gadgrect.o:	gadgrect.c	$(DEPS)
 glitch.o:	glitch.c	$(DEPS)
+gradient.o:	gradient.c	$(DEPS)
 
 halfsize.o:	halfsize.c	$(DEPS)
 
@@ -153,7 +154,7 @@ OBJECTS =	7seg.o							\
 		doublesz.o drawalpha.o drawing.o drawpatt.o		\
 		effects.o effects2.o effects3.o extractbits.o		\
 		filtadapt.o filtres.o					\
-		gadgrect.o glitch.o					\
+		gadgrect.o glitch.o gradient.o				\
 		halfsize.o						\
 		image.o	imprime.o					\
 		luts15bits.o						\

Lib/foo.c

@@ -17,17 +17,15 @@ return 0;
 }
 
 /*		==============================				*/
-void mk_lut(unsigned char lut[])
-{
-int		idx, uc;
-float		fidx;
 
-for (idx=0; idx<256; idx++) {
-	fidx = (float)idx / 255.0;
-	uc = (unsigned char)(255.0*(0.5 - 0.5 * cos(3.141592654*fidx)));
-	lut[idx] = uc;
-	printf("%7d    %7d\n", idx, uc); 
-	}
+void essai_gradients(void)
+{
+int		foo;
+
+foo = Image_plot_H_gradient("foo.tga", 640, 200);
+fprintf(stderr, "plot h gradient -> %d\n", foo);
+foo = Image_plot_V_gradient("foo.tga", 900, 200);
+fprintf(stderr, "plot v gradient -> %d\n", foo);
 }
 /*		==============================				*/
 int essai_draw_paint_rect(char *outga)
@@ -77,9 +75,8 @@ return OLL_KORRECT;
 int main(int argc, char *argv[])
 {
 int		foo;
-unsigned char	Lut[256];
 
-mk_lut(Lut);
+essai_gradients();
 
 #if 0
 Image_print_version(2);

Lib/gradient.c

@@ -0,0 +1,60 @@
+/*
+			gradient.c
+			----------
+
+	new: 	Sun Sep 17 20:47:57 UTC 2023
+
+*/
+
+#include  <stdio.h>
+#include  <string.h>
+#include  <stdlib.h>
+#include  <math.h>
+
+#include  "../tthimage.h"
+
+/*::------------------------------------------------------------------::*/
+int Image_plot_H_gradient(char *fname, int w, int h)
+{
+Image_Desc		*img;
+int			x, y, pix, foo;
+float			fval;
+
+if ( (img = Image_alloc(w, h, IMAGE_RGB)) == NULL )	{
+#if DEBUG_LEVEL
+	fprintf(stderr, "%s: alloc of img failed, file=%s\n", __func__, fname);
+#endif
+	return IMAGE_NO_MEM;
+	}
+
+for (x=0; x<w; x++) {
+	fval = (float)x / (float)(w-1);
+	pix = (int)(fval * 255.0);
+#if DEBUG_LEVEL > 1
+	printf("%5d    %6.3f    %5d\n", x, fval, pix);
+#endif
+	for (y=0; y<h; y++) {
+		(img->Rpix[y])[x] = pix;
+		(img->Gpix[y])[x] = pix;
+		(img->Bpix[y])[x] = pix;
+		}
+	}
+
+foo = Image_TGA_save(fname, img, 0);
+if (foo) {
+	fprintf(stderr, "%s: err write to '%s'\n", __func__, fname);
+	return FULL_NUCKED;
+	}
+
+Image_DeAllocate(img);	free(img);
+
+return FUNC_IS_BETA;
+}
+
+/*::------------------------------------------------------------------::*/
+int Image_plot_V_gradient(char *fname, int w, int h)
+{
+
+return FUNC_IS_ALPHA;
+}
+/*::------------------------------------------------------------------::*/