Added rudimentary write support for Truecolor TGA Images.

CMakeLists.txt

@@ -15,6 +15,7 @@ set(SOURCE_FILES
         src/test.c
         src/TGAImage.c
         src/TGADecode.c
+        src/TGAEncode.c
         )
 
 IF (CMAKE_COMPILER_IS_GNUCC)

include/TGAImage.h

@@ -12,9 +12,10 @@ typedef enum {
     TGA_GEN_IO_ERR              = 4,
     TGA_READ_ERR                = 5,
     TGA_WRITE_ERR               = 6,
-    TGA_IMAGE_IMMUTABLE_ERR     = 7,
-    TGA_UNSUPPORTED             = 8,
-    TGA_INTERNAL_ERR            = 9
+    TGA_INV_FILE_NAME           = 7,
+    TGA_IMAGE_IMMUTABLE_ERR     = 8,
+    TGA_UNSUPPORTED             = 9,
+    TGA_INTERNAL_ERR            = 10
 } TGAError;
 
 typedef enum {
@@ -43,6 +44,7 @@ TGAError TGA_ERR;
 TGAError tga_error(void); /* Returns the current error, if any. */
 void tga_clear_error(void);
 TGAImage *read_tga_image(FILE *file);
+int write_tga_image(TGAImage *image, const char *filename);
 TGAImage *new_tga_image(TGAColorType type, uint8_t depth,
                         uint16_t width, uint16_t height);
 void free_tga_image(TGAImage* image);

src/TGAEncode.c

@@ -0,0 +1,99 @@
+#include <stdint.h>
+#include <stdlib.h>
+
+#include "Private/TGAPrivate.h"
+
+static int _write_tga_header(TGAImage *image, FILE *file)
+{
+    uint8_t data[TGA_HEADER_SIZE] = {0};
+    check(_tga_sanity(image), TGA_INV_IMAGE_PNT, "Invalid TGAImage Pointer.");
+    check(file, TGA_INV_FILE_PNT, "Invalid file pointer passed.");
+    check(fseek(file, 0, SEEK_SET) == 0, TGA_GEN_IO_ERR,
+            "Unable to seek to beginning of file.");
+    data[0] = image->_meta->id_length;
+    data[1] = image->_meta->c_map_type;
+    data[2] = image->_meta->image_type;
+    *((uint16_t*)(data+3)) = image->_meta->c_map_start;
+    *((uint16_t*)(data+5)) = image->_meta->c_map_length;
+    data[7] = image->_meta->c_map_depth;
+    *((uint16_t*)(data+8)) = image->_meta->x_offset;
+    *((uint16_t*)(data+10)) = image->_meta->y_offset;
+    *((uint16_t*)(data+12)) = image->_meta->width;
+    *((uint16_t*)(data+14)) = image->_meta->height;
+    data[16] = image->_meta->pixel_depth;
+    data[17] = image->_meta->image_descriptor;
+
+    check(fwrite(data, TGA_HEADER_SIZE, 1, file) == 1, TGA_WRITE_ERR,
+            "Unable to write TGA Header.");
+    return 1;
+error:
+    return 0;
+}
+
+static int _write_tga_id_field(TGAImage *image, FILE *file)
+{
+    check(file, TGA_INV_FILE_PNT, "Invalid FILE Pointer.");
+    check(_tga_sanity(image), TGA_INV_IMAGE_PNT, "Invalid TGAImage Pointer.");
+    check(image->_meta->id_length != 0 && image->id_field, TGA_INTERNAL_ERR,
+            "TGA Image ID Null or 0. This should not have been called.");
+    if(ftell(file) != TGA_HEADER_SIZE)
+        check(fseek(file, TGA_HEADER_SIZE, SEEK_SET) == 0, TGA_GEN_IO_ERR,
+                "Unable to seek to beginning of ID Field.");
+    check(fwrite(image->id_field, image->_meta->id_length, 1, file) == 1,
+            TGA_WRITE_ERR, "Unable to write ID Field to file.");
+    return 1;
+error:
+    return 0;
+}
+
+static int _write_tga_image_data(TGAImage *image, FILE *file)
+{
+    uint8_t depth = 0;
+    uint32_t total = 0;
+
+    check(_tga_sanity(image), TGA_INV_IMAGE_PNT, "Invalid TGAImage Pointer.");
+    check(file, TGA_INV_FILE_PNT, "Invalid File Pointer.");
+
+    if(image->_meta->image_type == TGA_NO_DATA ||
+        image->_meta->image_type == TGA_INVALID_TYPE)
+        return 1; /* No Data to be written, according to meta-data. */
+
+    depth = (uint8_t)((image->_meta->pixel_depth + 7) / 8);
+    total = image->_meta->width * image->_meta->height * depth;
+    if(total == 0)
+        return 1;
+
+    check(image->data, TGA_INV_IMAGE_PNT, "Data missing.");
+    check(fwrite(image->data, total, 1, file) == 1, TGA_WRITE_ERR,
+            "Unable to write image data to file.");
+    return 1;
+error:
+    return 0;
+}
+
+int write_tga_image(TGAImage *image, const char* filename)
+{
+    FILE *file = NULL;
+    check(_tga_sanity(image), TGA_INV_IMAGE_PNT, "Invalid TGAImage Pointer.");
+    check(image->_meta->image_type == TGA_TRUECOLOR, TGA_UNSUPPORTED,
+            "Currently, only writing for TRUECOLOR TGA Images is supported.");
+    check(image->version == 1 || image->version == 2, TGA_UNSUPPORTED,
+            "Unsupported TGA Version.");
+    check(filename && filename[0] != '\0', TGA_INV_FILE_NAME,
+            "Invalid or Null filename.");
+    file = fopen(filename, "wb");
+    check(file, TGA_WRITE_ERR, "Unable to open file for writing.");
+
+    check(_write_tga_header(image, file), tga_error(),
+            "Unable to write TGA Header.");
+    if(image->_meta->id_length > 0)
+        check(_write_tga_id_field(image, file), tga_error(),
+                "Unable to write TGA ID Field.");
+    check(_write_tga_image_data(image, file), tga_error(),
+            "Unable to write TGA Data to file.");
+    return 1;
+error:
+    if(file)
+        fclose(file);
+    return 0;
+}

src/test.c

@@ -11,9 +11,9 @@ static void print_tga_data(TGAImage *img)
 
 int main(int argc, char **argv)
 {
-    if(argc != 2)
+    if(argc != 3)
     {
-        fprintf(stderr, "USAGE: TGAReader <image>\n");
+        fprintf(stderr, "USAGE: TGAReader <image> <newname>\n");
         return 1;
     }
 
@@ -30,6 +30,7 @@ int main(int argc, char **argv)
         return tga_error();
     }
     print_tga_data(img);
+    write_tga_image(img, argv[2]);
     free_tga_image(img);
     fclose(img_file);
     return 0;