HDR texture support

2 files changed, 233 insertions, 31 deletions

diff --git a/convtexture.c b/convtexture.c
index b3be7dc..e5b603b 100644
--- a/convtexture.c
+++ b/convtexture.c
@@ -1,5 +1,6 @@
 #include <stdio.h>
 #include <stdlib.h>
+#include <math.h>
 
 #include "plat.h"
 #include "str.h"
@@ -263,11 +264,15 @@ void compress_bc5(Colour* pixels, int w, int h, FILE* f) {
 	}
 }
 
-void convert(Image* image, Texture_Format target, FILE* f) {
+void write_header(FILE* f, int w, int h, Texture_Format fmt) {
 	fwrite("TXTR", 1, 4, f);
-	fwrite(&image->w, 1, 4, f);
-	fwrite(&image->h, 1, 4, f);
-	fwrite(&target, 1, 4, f);
+	fwrite(&w, 1, 4, f);
+	fwrite(&h, 1, 4, f);
+	fwrite(&fmt, 1, 4, f);
+}
+
+void convert(Image* image, Texture_Format target, FILE* f) {
+	write_header(f, image->w, image->h, target);
 	switch (target) {
 		case texture_format_bc1:
 			compress_bc1(image->pixels, image->w, image->h, f);
@@ -294,34 +299,13 @@ Texture_Format texture_format_from_string(const char* s) {
 	return (Texture_Format)0;
 }
 
-int main(int argc, const char** argv) {
-	FILE* outfile, * infile;
-	char bmp_magic[2];
+int proc_bitmap(FILE* infile, FILE* outfile, Texture_Format target) {
 	unsigned bmp_offset;
 	int bmp_w, bmp_h, s, x, y;
 	unsigned short bmp_bits;
 	Colour* buffer;
 	Image img;
 	Colour pixel;
-	Texture_Format target;
-
-	if (argc < 4) {
-		print_err("Usage: %s infile outfile format.\n", argv[0]);
-		return 1;
-	}
-
-	infile = fopen(argv[1], "rb");
-	if (!infile) {
-		print_err("Failed to open %s.\n", argv[1]);
-		return 2;
-	}
-	target = texture_format_from_string(argv[3]);
-
-	fread(bmp_magic, 2, 1, infile);
-	if (bmp_magic[0] != 'B' || bmp_magic[1] != 'M') {
-		print_err("Not a valid bitmap file.\n");
-		return 3;
-	}
 
 	fseek(infile, 10, SEEK_SET);
 	fread(&bmp_offset, 4, 1, infile);
@@ -360,11 +344,6 @@ int main(int argc, const char** argv) {
 			buffer[x + (bmp_h - y - 1) * bmp_w] = pixel;
 		}
 	}
-	outfile = fopen(argv[2], "wb");
-	if (!outfile) {
-		print_err("Failed to open %s.\n", argv[2]);
-		return 6;
-	}
 	img.pixels = buffer;
 	img.w = bmp_w;
 	img.h = bmp_h;
@@ -373,3 +352,222 @@ int main(int argc, const char** argv) {
 	return 0;
 }
 
+typedef struct {
+	float r, g, b;
+} Hdr_Pixel;
+
+Hdr_Pixel hdr_pixel(uint8_t* bytes) {
+	Hdr_Pixel p;
+	float f = ldexp(1.0f, (int)bytes[3] - (128 + 8));
+	p.r = ((float)bytes[0] + 0.5f) * f;
+	p.g = ((float)bytes[1] + 0.5f) * f;
+	p.b = ((float)bytes[2] + 0.5f) * f;
+	return p;
+}
+
+/* from open xr */
+uint16_t f2h(uint32_t i) {
+	int s =  (i >> 16) & 0x00008000;
+	int e = ((i >> 23) & 0x000000ff) - (127 - 15);
+	int m =   i        & 0x007fffff;
+	if (e <= 0)
+	{
+		if (e < -10)
+			return s;
+		m = m | 0x00800000;
+		int t = 14 - e;
+		int a = (1 << (t - 1)) - 1;
+		int b = (m >> t) & 1;
+		m = (m + a + b) >> t;
+		return s | m;
+	}
+	else if (e == 0xff - (127 - 15))
+	{
+		if (m == 0)
+			return s | 0x7c00;
+		else
+		{
+			m >>= 13;
+			return s | 0x7c00 | m | (m == 0);
+		}
+	}
+	else
+	{
+		m = m + 0x00000fff + ((m >> 13) & 1);
+		if (m & 0x00800000)
+		{
+			m =  0;
+			e += 1;
+		}
+		if (e > 30)
+			return s | 0x7c00;
+		return s | (e << 10) | (m >> 13);
+	}
+}
+
+void write_halves(FILE* f, int c, float* pixels) {
+	int i;
+	for (i = 0; i < c; i++) {
+		uint16_t h = f2h(*(uint32_t*)&pixels[i]);
+		fwrite(&h, 2, 1, f);
+	}
+}
+
+int proc_hdr(FILE* infile, FILE* outfile, int half) {
+	char buf[256];
+	char* tok;
+	int w, h, i;
+	Hdr_Pixel* pixels;
+	uint8_t* row;
+	int valid = 0;
+	fseek(infile, 0, SEEK_SET);
+	while (fgets(buf, sizeof buf, infile)) {
+		if (string_equal(buf, "FORMAT=32-bit_rle_rgbe\n"))
+			valid = 1;
+		if (buf[0] == '\n') break;
+	}
+	if (!valid) {
+		print_err("Format unsupported.\n");
+		return 10;
+	}
+	tok = fgets(buf, sizeof buf, infile);
+	if (tok[0] != '-' || tok[1] != 'Y') {
+		print_err("Format unsupported.\n");
+		return 11;
+	}
+	for (tok = tok + 2; *tok == ' '; tok++);
+	h = (int)strtol(tok, &tok, 10);
+	for (; *tok == ' '; tok++);
+	if (tok[0] != '+' || tok[1] != 'X') {
+		print_err("Format unsupported.\n");
+		return 11;
+	}
+	for (tok = tok + 2; *tok == ' '; tok++);
+	w = (int)strtol(tok, &tok, 10);
+	if (w < 8 || w > 0x7ffff) {
+		/* todo */
+		print_err("Format unsupported.\n");
+		return 12;
+	}
+	pixels = malloc(w * h * sizeof *pixels);
+	row = malloc(w * 4);
+	for (i = 0; i < h; i++) {
+		int a, b, c, d, j;
+		a = fgetc(infile);
+		b = fgetc(infile);
+		c = fgetc(infile);
+		d = fgetc(infile);
+		if (d == EOF) {
+			print_err("Unexpected end of image file.\n");
+			return 13;
+		}
+		if (b != 2 || (c & 0x80)) {
+			int j, shift = 0;
+			row[0] = a;
+			row[1] = b;
+			row[2] = c;
+			row[3] = d;
+			for (j = 1; j < w; j++) {
+				uint8_t* p = &row[j * 4];
+				p[0] = fgetc(infile);
+				p[1] = fgetc(infile);
+				p[2] = fgetc(infile);
+				p[3] = fgetc(infile);
+				if (
+					p[0] == 1 &&
+					p[1] == 1 &&
+					p[2] == 1
+				) {
+					int k;
+					for (k = p[3] << shift; k > 0; k--) {
+						p[0] = p[-4];
+						p[1] = p[-3];
+						p[2] = p[-2];
+						p[3] = p[-1];
+						p += 4;
+						j++;
+					}
+					shift += 8;
+				} else
+					shift = 0;
+			}
+			goto convert;
+		}
+		if (((c << 8) | d) != w) {
+			print("%d, %d\n", i, ((c << 8) | d));
+			print_err("Corrupt run.\n");
+			return 14;
+		}
+		for (j = 0; j < 4; j++) {
+			int k;
+			for (k = 0; k < w;) {
+				int d1 = fgetc(infile), d2;
+				if (d1 == EOF) {
+					print_err("Unexpected end of image file.\n");
+					return 14;
+				}
+				if (d1 > 128) {
+					d1 &= 127;
+					d2 = fgetc(infile);
+					for (; d1--; k++)
+						row[k * 4 + j] = (uint8_t)d2;
+				} else
+					for (; d1--; k++)
+						row[k * 4 + j] = (uint8_t)fgetc(infile);
+			}
+		}
+		convert:
+		for (j = 0; j < w; j++) {
+			pixels[j + i * w] = hdr_pixel(&row[j * 4]);
+		}
+	}
+	if (half) {
+		write_header(outfile, w, h, texture_format_rgb16f);
+		write_halves(outfile, w * h * 3, (float*)pixels);
+	} else {
+		write_header(outfile, w, h, texture_format_rgb32f);
+		fwrite(pixels, sizeof *pixels, w * h, outfile);
+	}
+	fclose(outfile);
+	return 0;
+}
+
+int main(int argc, const char** argv) {
+	FILE* outfile, * infile;
+	char magic[11];
+	Texture_Format target;
+
+	if (argc < 4) {
+		print_err("Usage: %s infile outfile format.\n", argv[0]);
+		return 1;
+	}
+
+	infile = fopen(argv[1], "rb");
+	if (!infile) {
+		print_err("Failed to open %s.\n", argv[1]);
+		return 2;
+	}
+	target = texture_format_from_string(argv[3]);
+
+	outfile = fopen(argv[2], "wb");
+	if (!outfile) {
+		print_err("Failed to open %s.\n", argv[2]);
+		return 6;
+	}
+
+	fread(magic, 1, 10, infile); magic[10] = 0;
+	if (magic[0] == 'B' && magic[1] == 'M') {
+		return proc_bitmap(infile, outfile, target);
+	}
+	if (string_equal(magic, "#?RADIANCE")) {
+		int half = target == texture_format_rgb16f;
+		if (!half && target != texture_format_rgb32f) {
+			print_err("Unsupported target format.\n");
+			return 40;
+		}
+		return proc_hdr(infile, outfile, half);
+	}
+	print_err("Invalid image file.\n");
+	return 80;
+}
+
diff --git a/video.cpp b/video.cpp
index 4e38bc5..ef724bf 100644
--- a/video.cpp
+++ b/video.cpp
@@ -3689,6 +3689,10 @@ size_t Texture_Loader::calc_size(
 			return (w / 4) * (h / 4) * 16;
 		case texture_format_r8i:
 			return w * h;
+		case texture_format_rgb16f:
+			return w * h * 6;
+		case texture_format_rgb32f:
+			return w * h * 12;
 		default:
 			print_err("Can't load this texture format.\n"); 
 			pbreak(45498);