bmx can load "stamps"

compiler/res/prog8lib/cx16/bmx.p8

@@ -2,6 +2,12 @@
 ; Only uncompressed images, of width 320 or 640, are supported for now.
 ; BMX Specification: https://cx16forum.com/forum/viewtopic.php?t=6945
 
+
+; TODO:  refactor loading:   bmx.open() - reads header .   bmx.continue_load() - reads the palette+bitmap.   bmx.close()  -cleanup  bmx.save() stays the same
+; TODO: ability to save "stamps" , bitmaps that are only a region of the screen.
+; TODO: load 4bpp/2bpp/1bpp images
+; TODO: save 4bpp/2bpp/1bpp images
+
 %import diskio
 
 bmx {
@@ -47,7 +53,8 @@ bmx {
                         goto load_end
                     }
                     if width!=320 and width!=640 {
-                        error_message = "width not 320 or 640"      ; TODO: deal with other widths
+                        ; note: use load_stamp() to read other sizes
+                        error_message = "width not 320 or 640"
                         goto load_end
                     }
                     if compression {
@@ -66,6 +73,57 @@ bmx {
         } else
             error_message = diskio.status()
 
+load_end:
+        diskio.f_close()
+        diskio.drivenumber = old_drivenumber
+        return error_message==0
+    }
+
+    sub load_stamp(ubyte drivenumber, str filename, ubyte vbank, uword vaddr, uword screenwidth) -> bool {
+        ; Loads a BMX bitmap "stamp" image and palette into vram. (and Header info into the bmx.* variables)
+        ; "Stamp" means: load an image that is smaller than the screen (so we need to pad around it)
+        ; Parameters:
+        ; the drive number and filename to load,
+        ; and the vram bank and address where the bitmap data should go,
+        ; finally the screen width that the stamp image is loaded into.
+        ; You can set the max_width and max_height variables first, if you want this routine to check those.
+        ; Note: does not change vera screen mode or colordepth! You have to do that yourself!
+        ; Returns: success status. If false, error_message points to the error message string.
+        error_message = 0
+        ubyte old_drivenumber = diskio.drivenumber
+        diskio.drivenumber = drivenumber
+        if diskio.f_open(filename) {
+            diskio.reset_read_channel()
+            if read_header() {
+                if parse_header() {
+                    if max_width and width>max_width {
+                        error_message = "image too large"
+                        goto load_end
+                    }
+                    if max_height and height>max_height {
+                        error_message = "image too large"
+                        goto load_end
+                    }
+                    if width>screenwidth {
+                        error_message = "image too large"
+                        goto load_end
+                    }
+                    if compression {
+                        error_message = "compression not supported"
+                        goto load_end
+                    }
+                    if read_palette() {
+                        if not read_bitmap_padded(vbank, vaddr, screenwidth)
+                            error_message = "bitmap error"
+                    } else
+                        error_message = "palette error"
+                } else
+                    error_message = "invalid bmx file"
+            } else
+                error_message = "invalid bmx file"
+        } else
+            error_message = diskio.status()
+
 load_end:
         diskio.f_close()
         diskio.drivenumber = old_drivenumber
@@ -129,14 +187,14 @@ load_end:
         ; drive number and filename to save to,
         ; vram bank and address of the bitmap data to save.
         ; Returns: success status. If false, error_message points to the error message string.
-        ; TODO: how to save bitmaps that are not the full visible screen width (non-contiguous scanlines)
+        ; TODO: how to save bitmaps that are not the full visible screen width (non-contiguous scanlines)?
         if compression {
             error_message = "compression not supported"
             return false
         }
         error_message = 0
         if width!=320 and width!=640 {
-            error_message = "width not 320 or 640"      ; TODO: deal with other widths
+            error_message = "width not 320 or 640"
             goto save_end
         }
         ubyte old_drivenumber = diskio.drivenumber
@@ -211,14 +269,28 @@ save_end:
         return cbm.READST()==0 or cbm.READST()&$40    ; no error or eof?
     }
 
+    sub read_bitmap_padded(ubyte vbank, uword vaddr, uword screenwidth) -> bool {
+        ; load bitmap "stamp" into vram from the currently active input file
+        cx16.r3 = bytes_per_scanline(width)         ; num bytes per image scanline
+        cx16.r2 = bytes_per_scanline(screenwidth)   ; num bytes per screen scanline
+        repeat height {
+            cx16.vaddr(vbank, vaddr, 0, 1)
+            read_scanline(cx16.r3)
+            vaddr += cx16.r2
+            if_cs
+                vbank++
+        }
+        return cbm.READST()==0 or cbm.READST()&$40    ; no error or eof?
+    }
+
     sub read_bitmap(ubyte vbank, uword vaddr) -> bool {
         ; load contiguous bitmap into vram from the currently active input file
-        ; TODO how to deal with bitmaps that are smaller than the screen?
-        cx16.vaddr(vbank, vaddr, 0, 1)
         cx16.r3 = bytes_per_scanline(width)
+        cx16.vaddr(vbank, vaddr, 0, 1)
         repeat height
             read_scanline(cx16.r3)
         return cbm.READST()==0 or cbm.READST()&$40    ; no error or eof?
+    }
 
     sub read_scanline(uword size) {
         while size {
@@ -231,8 +303,6 @@ save_end:
             }
             size -= cx16.r0
         }
-            return
-        }
     }
 
     sub write_header() -> bool {
@@ -268,7 +338,6 @@ save_end:
 
     sub write_bitmap(ubyte vbank, uword vaddr) -> bool {
         ; save contiguous bitmap from vram to the currently active output file
-        ; TODO how to deal with bitmaps that are smaller than the screen
         cx16.vaddr(vbank, vaddr, 0, 1)
         cx16.r3 = bytes_per_scanline(width)
         repeat height
@@ -293,14 +362,8 @@ save_end:
     }
 
     sub bytes_per_scanline(uword w) -> uword {
-        when bitsperpixel {
+        ubyte[4] shifts = [3,2,1,0]
-            1 -> cx16.r0L = 3
+        return w >> shifts[vera_colordepth]
-            2 -> cx16.r0L = 2
-            4 -> cx16.r0L = 1
-            8 -> return w
-            else -> return 0
-        }
-        return w >> cx16.r0L
     }
 
     sub parse_header() -> bool {

compiler/res/prog8lib/cx16/diskio.p8

@@ -281,7 +281,8 @@ close_end:
         ;    note: only a single iteration loop can be active at a time!
         ;    Returns true if the file is successfully opened and readable.
         ;    No need to check status(), unlike f_open_w() !
-        ;    NOTE: the default input isn't yet set to this logical file, you can use reset_read_channel() to do this!
+        ;    NOTE: the default input isn't yet set to this logical file, you must use reset_read_channel() to do this,
+        ;          if you're going to read from it yourself instead of using f_read()!
         f_close()
 
         cbm.SETNAM(string.length(filenameptr), filenameptr)

compiler/res/prog8lib/diskio.p8

@@ -273,7 +273,8 @@ close_end:
         ;    note: only a single iteration loop can be active at a time!
         ;    Returns true if the file is successfully opened and readable.
         ;    No need to check status(), unlike f_open_w() !
-        ;    NOTE: the default input isn't yet set to this logical file, you can use reset_read_channel() to do this!
+        ;    NOTE: the default input isn't yet set to this logical file, you must use reset_read_channel() to do this,
+        ;          if you're going to read from it yourself instead of using f_read()!
         f_close()
 
         cbm.SETNAM(string.length(filenameptr), filenameptr)

examples/cx16/showbmx.p8

@@ -18,6 +18,7 @@ main {
         repeat {
             txt.print("\nenter bmx image filename: ")
             if txt.input_chars(&filename) {
+
                 if bmx.load_header(8, filename) {
                     txt.print("\nsize: ")
                     txt.print_uw(bmx.width)
@@ -34,16 +35,37 @@ main {
                     bmx.palette_buffer_ptr = memory("palette", 512, 0)
                     sys.memset(bmx.palette_buffer_ptr, 512, 0)
                     palette.set_rgb(bmx.palette_buffer_ptr, 256)
+                    bmx.max_width = 320
+                    bmx.max_height = 240
 
-                    ; switch to correct screen mode and color depth
+                    ; switch to bitmap screen mode and color depth:  320*240
-                    void cx16.screen_mode($80, false)
+                    void cx16.screen_mode($80, false)       ; we're lazy and just use a kernal routine to set up the basics
                     cx16.VERA_L0_CONFIG = cx16.VERA_L0_CONFIG & %11111100 | bmx.vera_colordepth
 
                     ; now load the image
+                    if bmx.width==320 {
+                        ; can use the fast, full-screen load routine
                         if bmx.load(8, filename, 0, 0) {
+                            if bmx.height<240 {
+                                ; fill the remaining bottom part of the screen
+                                cx16.GRAPH_set_colors(bmx.border, bmx.border, 99)
+                                cx16.GRAPH_draw_rect(0, bmx.height, 320, 240-bmx.height, 0, true)
+                            }
                             activate_palette()
                             void txt.waitkey()
                         }
+                    } else {
+                        ; clear the screen with the border color
+                        cx16.GRAPH_set_colors(0, 0, bmx.border)
+                        cx16.GRAPH_clear()
+                        ; need to use the slower load routine that does padding
+                        ; center the image on the screen nicely
+                        uword offset = (320-bmx.width)/2 + (240-bmx.height)/2*320
+                        if bmx.load_stamp(8, filename, 0, offset, 320) {
+                            activate_palette()
+                            void txt.waitkey()
+                        }
+                    }
                 }
 
                 cbm.CINT()  ; reset screen
@@ -60,6 +82,7 @@ main {
 
     sub activate_palette() {
         ; copies the pallette data from the memory buffer into vram
+        cx16.VERA_DC_BORDER = bmx.border
         cx16.r1 = bmx.palette_buffer_ptr
         cx16.r2L = bmx.palette_start
         cx16.r3L = bmx.palette_entries

examples/test.p8

@@ -13,6 +13,9 @@ main {
             txt.print("\nprog8's parse_f: ")
             float value = floats.parse_f(buffer)
             floats.print_f(value)
+
+            ; floats.VAL_1 is defined as:
+            ; romsub $fe09 = VAL_1(uword string @XY, ubyte length @A) clobbers(A,X,Y) -> float @FAC1
             txt.print("\nrom val_1: ")
             value = floats.VAL_1(buffer, string.length(buffer))
             floats.print_f(value)