Impl VDP register bits tracing

1 files changed, 113 insertions, 6 deletions

diff --git a/vdp.cpp b/vdp.cpp
index 02cc21c..df3a7cc 100644
--- a/vdp.cpp
+++ b/vdp.cpp
@@ -131,6 +131,117 @@ static constexpr uint16_t kScrollSpeedMask = BitsCountToMask(10);
 // Each pixel has 4 bit depth color
 static constexpr uint16_t kPixelColorMask = BitsCountToMask(kBitsPerPixel);
 
+static const char* reg_mode_set_1_bits[8] = {
+    "Unused(7)",
+    "Unused(6)",
+    "Unused(5)",
+    "HInt(4)",
+    "Unused(3)",
+    "AllBitsFromColor(2)",
+    "HVCounter(1)",
+    "Unused(0)",
+};
+
+static const char* reg_mode_set_2_bits[8] = {
+    "Unused(7)",
+    "Display(6)",
+    "VInt(5)",
+    "DMA(4)",
+    "V30Cell(3)",
+    "Unused(2)",
+    "Unused(1)",
+    "Unused(0)",
+};
+
+static const char* reg_mode_set_3_bits[8] = {
+    "Unused(7)",
+    "Unused(6)",
+    "Unused(5)",
+    "Unused(4)",
+    "ExtInt(3)",
+    "2CellVScroll(2)",
+    "HScrollHi(1)",
+    "HScrollLo(0)",
+};
+
+static const char* reg_mode_set_4_bits[8] = {
+    "H40CellHi(7)",
+    "Unused(6)",
+    "Unused(5)",
+    "Unused(4)",
+    "Shadow(3)",
+    "InterlaceHi(2)",
+    "InterlaceLo(1)",
+    "H40CellLo(0)",
+};
+
+static void TraceRegBits(FILE* s, const char* bits_desc[8], const uint8_t val)
+{
+    fprintf(s, "(");
+    bool separator{};
+    for (size_t i = 0; i < 8; i++) {
+        if (val & (1 << (7 - i))) {
+            if (separator) {
+                fprintf(s, " | ");
+                separator = false;
+            }
+            fprintf(s, bits_desc[i]);
+            separator = true;
+        }
+    }
+    fprintf(s, ")");
+}
+
+static void TraceRegWrite(FILE* const s, const uint8_t reg, const uint8_t val)
+{
+    const auto reg_id = static_cast<VDP::RegID>(reg);
+    fprintf(s, ": reg 0x%02x(%s) = 0x%02x", reg, VDP::RegIDToString(reg_id), val);
+    switch (reg_id) {
+    case VDP::RegID::kModeSet1:
+        return TraceRegBits(s, reg_mode_set_1_bits, val);
+    case VDP::RegID::kModeSet2:
+        return TraceRegBits(s, reg_mode_set_2_bits, val);
+    case VDP::RegID::kScrollAAddress:
+        break;
+    case VDP::RegID::kWindowAddress:
+        break;
+    case VDP::RegID::kScrollBAddress:
+        break;
+    case VDP::RegID::kSpritesTableAddress:
+        break;
+    case VDP::RegID::kBackgroundColor:
+        break;
+    case VDP::RegID::kHint:
+        break;
+    case VDP::RegID::kModeSet3:
+        return TraceRegBits(s, reg_mode_set_3_bits, val);
+    case VDP::RegID::kModeSet4:
+        return TraceRegBits(s, reg_mode_set_4_bits, val);
+    case VDP::RegID::kHScrollTableAddress:
+        break;
+    case VDP::RegID::kAutoIncrement:
+        break;
+    case VDP::RegID::kScrollSize:
+        break;
+    case VDP::RegID::kWindowHorizontalPosition:
+        break;
+    case VDP::RegID::kWindowVertialPosition:
+        break;
+    case VDP::RegID::kDMALengthCounterLow:
+        break;
+    case VDP::RegID::kDMALengthCounterHigh:
+        break;
+    case VDP::RegID::kDMASourceAddressLow:
+        break;
+    case VDP::RegID::kDMASourceAddressMid:
+        break;
+    case VDP::RegID::kDMASourceAddressHigh:
+        break;
+    case VDP::RegID::kRegistersCount:
+        break;
+    }
+}
+
 uint32_t VDP::Read(const uint32_t offset, const enum bitness bitness)
 {
     uint32_t ret{};
@@ -634,11 +745,7 @@ void VDP::writeControl(const uint16_t value)
         const uint8_t reg_num = (value >> 8) & 0x1f;
         const uint8_t reg_val = value & 0xff;
         if (DEBUG_TRACE_VDP_ACCESS) {
-            printf(
-                    ": reg 0x%02x(%s) = 0x%02x",
-                    reg_num,
-                    regIDToString(static_cast<RegID>(reg_num)),
-                    reg_val);
+            TraceRegWrite(stdout, reg_num, reg_val);
         }
         _reg[reg_num] = reg_val;
         // TODO print warnings of all invalid values or writes that ignore a mask
@@ -838,7 +945,7 @@ const char* VDP::addressModeToString(const uint8_t address_mode)
     return "Unknown";
 }
 
-const char* VDP::regIDToString(const RegID reg_id)
+const char* VDP::RegIDToString(const RegID reg_id)
 {
     switch (reg_id) {
     case RegID::kModeSet1: