Diff: BMPFile.cpp

Revision:

1:8cf4beca9695

Parent:

0:4617bf407fe5

Child:

2:89b273c12b0a

--- a/BMPFile.cpp	Wed Mar 04 00:29:12 2015 +0000
+++ b/BMPFile.cpp	Wed Mar 04 20:56:34 2015 +0000
@@ -15,11 +15,11 @@
     "AllocationFailed"
 };
 const char* BMPFile::FormatString[] = {
+    "OS2_V1",
+    "OS2_V2",
     "Windows_V3",
     "Windows_V4",
     "Windows_V5",
-    "OS2_V1",
-    "OS2_V2",
     "Unknown"
 };
 
@@ -28,15 +28,17 @@
     uint8_t  buf8[2];
     uint16_t buf16[2];
     uint32_t buf32[3];
-    uint32_t offset;
-
+    
     status = Success;
     format = Unknown;
     fileSize = 0;
+    paletteSize = 0;
     dataSize = 0;
+    stride = 0;
     width = 0;
     height = 0;
     colorDepth = 0;
+    palette = NULL;
     data = NULL;
     
     // Open file
@@ -63,11 +65,16 @@
     // (10 +4) Image data offset (unconfirmed)
     fread(buf32, 4, 3, fp);
     fileSize = buf32[0];
-    offset = buf32[2];
     
     // (14 +4) Header size
     fread(buf32, 4, 1, fp);
     switch (buf32[0]) {
+    case 12:  // OS/2 V1 format
+        format = OS2_V1;
+        break;
+    case 64:  // OS/2 V2 format
+        format = OS2_V2;
+        break;
     case 40:  // Windows V3 format
         format = Windows_V3;
         break;
@@ -77,17 +84,36 @@
     case 124:  // Windows V5 format
         format = Windows_V5;
         break;
-    case 12:  // OS/2 V1 format
-        format = OS2_V1;
-        break;
-    case 64:  // OS/2 V2 format
-        format = OS2_V2;
-        break;
     default:
         format = Unknown;
     }
     
     switch (format) {
+    case OS2_V1:
+        // (18 +2) Bitmap width
+        // (20 +2) Bitmap height
+        fread(buf16, 4, 2, fp);
+        width = (uint32_t) buf16[0];
+        height = (uint32_t) buf16[1];
+        
+        // (22 +2) Number of planes (unconfirmed)
+        // (24 +2) Color depth
+        fread(buf16, 2, 2, fp);
+        colorDepth = buf16[1];
+        switch (colorDepth) {
+        case 1: case 4: case 8:
+            paletteSize = paletteElemSize(format) * (1ul << colorDepth);
+            break;
+        case 16: case 24: case 32:  // No palette
+            paletteSize = 0;
+            break;
+        default:
+            paletteSize = 0;
+            status = UnsupportedDepth;
+            fclose(fp);
+            return;
+        }
+        break;
     case Windows_V3:
         // (18 +4) Bitmap width
         // (22 +4) Bitmap height
@@ -99,7 +125,15 @@
         // (28 +2) Color depth
         fread(buf16, 2, 2, fp);
         colorDepth = buf16[1];
-        if (colorDepth != 24) {
+        switch (colorDepth) {
+        case 1: case 4: case 8:
+            paletteSize = paletteElemSize(format) * (1ul << colorDepth);
+            break;
+        case 16: case 24: case 32:  // No palette
+            paletteSize = 0;
+            break;
+        default:
+            paletteSize = 0;
             status = UnsupportedDepth;
             fclose(fp);
             return;
@@ -114,20 +148,33 @@
         fread(buf32, 4, 3, fp);
         fread(buf32, 4, 3, fp);
         break;
+    case OS2_V2:
     case Windows_V4:
     case Windows_V5:
-    case OS2_V1:
-    case OS2_V2:
     case Unknown:
         status = UnsupportedFormat;
         fclose(fp);
         return;
     }
-    // Seek to image data offset
-    fseek(fp, offset, SEEK_SET);
+    
+    // Allocate palette space if needed
+    if (paletteSize) {
+        palette = new uint8_t[paletteSize];
+        
+        // Read palette data
+        fread(palette, 1, paletteSize, fp);
+    }
     
-    // Calculate data length
-    dataSize = ((colorDepth / 8) * width + 3) / 4 * 4 * height;
+    // Calculate stride / data length
+    if (colorDepth == 1) {
+        stride = ALIGN_BY_4((width + 7) / 8);
+    } else if (colorDepth == 4) {
+        stride = ALIGN_BY_4((width + 1) / 2);
+    } else {
+        // Color depth: 8, 16, 24, 32
+        stride = ALIGN_BY_4(width * colorDepth / 8);
+    }
+    dataSize = stride * height;
     
     // Allocate data space
     data = new uint8_t[dataSize];
@@ -139,7 +186,147 @@
 }
 
 BMPFile::~BMPFile() {
+    if (palette) {
+        delete[] palette;
+    }
     if (data) {
         delete[] data;
     }
 }
+
+uint32_t BMPFile::paletteElemSize(BMPFile::Format format) {
+    switch (format) {
+    case OS2_V1: case OS2_V2:
+        // BGR888
+        return 3;
+    case Windows_V3: case Windows_V4: case Windows_V5:
+        // BGRX8888
+        return 4;
+    default:
+        return 0;
+    }
+}
+
+int32_t BMPFile::paletteRed(uint8_t index) {
+    if (!palette) {
+        return -1;
+    }
+    switch (colorDepth) {
+    case 1: case 4: case 8:
+        if (index >= 1ul << colorDepth) {
+            return -1;
+        } else {
+            return palette[paletteElemSize(format) * index + 2];
+        }
+    default:
+        return -1;
+    }
+}
+
+int32_t BMPFile::paletteGreen(uint8_t index) {
+    if (!palette) {
+        return -1;
+    }
+    switch (colorDepth) {
+    case 1: case 4: case 8:
+        if (index >= 1ul << colorDepth) {
+            return -1;
+        } else {
+            return palette[paletteElemSize(format) * index + 1];
+        }
+    default:
+        return -1;
+    }
+}
+
+int32_t BMPFile::paletteBlue(uint8_t index) {
+    if (!palette) {
+        return -1;
+    }
+    switch (colorDepth) {
+    case 1: case 4: case 8:
+        if (index >= 1ul << colorDepth) {
+            return -1;
+        } else {
+            return palette[paletteElemSize(format) * index];
+        }
+    default:
+        return -1;
+    }
+}
+
+int32_t BMPFile::red(uint32_t x, uint32_t y) {
+    if (x >= width || y >= height) {
+        return -1;
+    }
+    if (!data) {
+        return -1;
+    }
+    switch (colorDepth) {
+    case 1:  // Indexed from palette
+        return paletteRed((data[stride * y + x / 8] >> 7 - x % 8) & 0x01);
+    case 4:  // Indexed from palette
+        return paletteRed((data[stride * y + x / 2] >> 4 * (1 - x % 2)) & 0x0f);
+    case 8:  // Indexed from palette
+        return paletteRed(data[stride * y + x]);
+    case 16:  // BGR565 (bbbbbggg:gggrrrrr)
+        return data[stride * y + 2 * x + 1] & 0x1f;
+    case 24:  // BGR888
+        return data[stride * y + 3 * x + 1];
+    case 32:  // BGRX8888
+        return data[stride * y + 4 * x + 1];
+    default:
+        return -1;
+    }
+}
+
+int32_t BMPFile::green(uint32_t x, uint32_t y) {
+    if (x >= width || y >= height) {
+        return -1;
+    }
+    if (!data) {
+        return -1;
+    }
+    switch (colorDepth) {
+    case 1:  // Indexed from palette
+        return paletteGreen((data[stride * y + x / 8] >> 7 - x % 8) & 0x01);
+    case 4:  // Indexed from palette
+        return paletteGreen((data[stride * y + x / 2] >> 4 * (1 - x % 2)) & 0x0f);
+    case 8:  // Indexed from palette
+        return paletteGreen(data[stride * y + x]);
+    case 16:  // BGR565 (bbbbbggg:gggrrrrr)
+        return (data[stride * y + 2 * x] & 0x07) << 3
+               | data[stride * y + 2 * x + 1] >> 5;
+    case 24:  // BGR888
+        return data[stride * y + 3 * x + 1];
+    case 32:  // BGRX8888
+        return data[stride * y + 4 * x + 1];
+    default:
+        return -1;
+    }
+}
+
+int32_t BMPFile::blue(uint32_t x, uint32_t y) {
+    if (x >= width || y >= height) {
+        return -1;
+    }
+    if (!data) {
+        return -1;
+    }
+    switch (colorDepth) {
+    case 1:  // Indexed from palette
+        return paletteBlue((data[stride * y + x / 8] >> 7 - x % 8) & 0x01);
+    case 4:  // Indexed from palette
+        return paletteBlue((data[stride * y + x / 2] >> 4 * (1 - x % 2)) & 0x0f);
+    case 8:  // Indexed from palette
+        return paletteBlue(data[stride * y + x]);
+    case 16:  // RGB565 (bbbbbggg:gggrrrrr)
+        return data[stride * y + 2 * x] >> 3;
+    case 24:  // BGR888
+        return data[stride * y + 3 * x];
+    case 32:  // BGRX8888
+        return data[stride * y + 4 * x];
+    default:
+        return -1;
+    }
+}