Add some bad experimental work on automatic sample format conversion.

resources/format_conversions.txt

+# The worlds worst programming language!
+#
+# The final result needs to be moved to the "r" variable. The input sample is "x".
+#
+# Instructions
+# ============
+# add [output] [a] [b] -> output = a + b
+# sub [output] [a] [b] -> output = a - b
+# mul [output] [a] [b] -> output = a * b
+# div [output] [a] [b] -> output = a / b
+# shl [output] [a] [b] -> output = a << b
+# shr [output] [a] [b] -> output = a >> b
+# sig [output] [b]     -> output = (sign bit in "a" is set) ? 1 : 0
+# mov [output] [a]     -> output = a;
+#
+# int [name] -> Declare an uninitialized 32-bit integer
+# flt [name] -> Declare an uninitialized 32-bit float
+
+# r = (x - 128) << 8
+u8->s16 {
+    sub r x 128;
+    shl r r 8;
+}
+
+# r = (x - 128) << 16
+u8->s24 {
+    sub r x 128;
+    shl r r 16;
+}
+
+# r = (x - 128) << 24
+u8->s32 {
+    sub r x 128;
+    shl r r 24;
+}
+
+# r = (x / 255) * 2 - 1
+u8->f32 {
+    div r x 255.0;
+    mul r r 2;
+    sub r r 1;
+}
+
+
+# r = x / (2147483647 + sign(x))
+u32->f32 {
+    int s;
+    sig s x;
+    add s s 2147483647;
+    div r x (flt)s;
+}
\ No newline at end of file

tools/malgen/source/malgen.cpp

+
+#define DR_IMPLEMENTATION
+#include "../../../../../dr_libs/dr.h"
+
+#include <vector>
+
+typedef struct
+{
+    const char* name;
+    const char* params[4];
+    int paramCount;
+} malgen_instruction;
+
+typedef struct
+{
+    const char* formatInStr;
+    const char* formatOutStr;
+    std::vector<malgen_instruction> instructions;
+} malgen_conversion_desc;
+
+typedef struct
+{
+    char* pFormatsFileData;
+    std::vector<malgen_conversion_desc> conversions;
+} malgen_context;
+
+void u8_to_s16(const unsigned char* px, short* pr, unsigned int count)
+{
+    int r;
+    for (unsigned int i = 0; i < count; ++i) {
+        int x = px[i];
+
+        r = x - 128;
+        r = x << 8;
+        pr[i] = r;
+    }
+}
+
+void u8_to_s24(const unsigned char* px, unsigned char* pr, unsigned int count)
+{
+    int r;
+    for (unsigned int i = 0; i < count; ++i) {
+        int x = px[i];
+
+        r = x - 128;
+        r = x << 16;
+        memcpy(&pr[i*3], &r, 3);
+    }
+}
+
+void u8_to_s32(const unsigned char* px, int* pr, unsigned int count)
+{
+    int r;
+    for (unsigned int i = 0; i < count; ++i) {
+        int x = px[i];
+
+        r = x - 128;
+        r = x << 24;
+        pr[i] = r;
+    }
+}
+
+void u8_to_f32(const unsigned char* pIn, float* pOut, unsigned int count)
+{
+    float r;
+    int   x;
+    unsigned int i = 0;
+    
+    switch ((uintptr_t)pIn & 0x3)
+    {
+    case 3:
+        x = pIn[i];
+        r = x / 255.0f;
+        r = r * 2;
+        r = r - 1;
+        pOut[i++] = r;
+    case 2:
+        x = pIn[i];
+        r = x / 255.0f;
+        r = r * 2;
+        r = r - 1;
+        pOut[i++] = r;
+    case 1:
+        x = pIn[i];
+        r = x / 255.0f;
+        r = r * 2;
+        r = r - 1;
+        pOut[i++] = r;
+    }
+
+    while (i+3 < count) {
+        float r[4];
+        int   x[4];
+        
+        x[0] = pIn[i+0];
+        x[1] = pIn[i+1];
+        x[2] = pIn[i+2];
+        x[3] = pIn[i+3];
+
+        r[0] = x[0] / 255.0f;
+        r[1] = x[1] / 255.0f;
+        r[2] = x[2] / 255.0f;
+        r[3] = x[3] / 255.0f;
+
+        r[0] = r[0] * 2;
+        r[1] = r[1] * 2;
+        r[2] = r[2] * 2;
+        r[3] = r[3] * 2;
+
+        r[0] = r[0] - 1;
+        r[1] = r[1] - 1;
+        r[2] = r[2] - 1;
+        r[3] = r[3] - 1;
+
+        pOut[i+0] = r[0];
+        pOut[i+1] = r[1];
+        pOut[i+2] = r[2];
+        pOut[i+3] = r[3];
+
+        i += 4;
+    }
+
+    switch (count - i)
+    {
+    case 3:
+        x = pIn[i];
+        r = x / 255.0f;
+        r = r * 2;
+        r = r - 1;
+        pOut[i++] = r;
+    case 2:
+        x = pIn[i];
+        r = x / 255.0f;
+        r = r * 2;
+        r = r - 1;
+        pOut[i++] = r;
+    case 1:
+        x = pIn[i];
+        r = x / 255.0f;
+        r = r * 2;
+        r = r - 1;
+        pOut[i++] = r;
+    }
+}
+
+int malgen_compile(malgen_context* pContext)
+{
+    size_t formatsFileData;
+    pContext->pFormatsFileData = dr_open_and_read_text_file("../../../resources/format_conversions.txt", &formatsFileData);
+    if (pContext->pFormatsFileData == NULL) {
+        printf("Failed to open sample format conversion definitions.\n");
+        return -1;
+    }
+
+    // The first part is going to blank out comments. It just makes the actual parsing soooo much simpler.
+    char* pRunningStr = pContext->pFormatsFileData;
+    for (;;) {
+        if (pRunningStr[0] == '\0') break;
+        if (pRunningStr[0] == '#') {
+            while (pRunningStr[0] != '\n') {
+                if (pRunningStr[0] == '\0') {
+                    break;
+                }
+
+                pRunningStr[0] = ' ';
+                pRunningStr += 1;
+            }
+        }
+        pRunningStr += 1;
+    }
+
+
+    malgen_conversion_desc currentFunc;
+    malgen_instruction currentInst;
+    memset(&currentInst, 0, sizeof(currentInst));
+    int currentParam = 0;
+    
+    // Level 0 = not inside a conversion function.
+    // Level 1 = inside a conversion function.
+    // Level 2 = inside an instruction (parsing parameters).
+    int level = 0;
+
+    pRunningStr = pContext->pFormatsFileData;
+    for (;;) {
+        if (pRunningStr[0] == '\0')
+            return 0;
+
+        if (level == 0) {
+            // Find the first non-whitespace.
+            for (;;) {
+                if (pRunningStr[0] == '\0') return 0;
+                if (!dr_is_whitespace(pRunningStr[0])) {
+                    break;
+                }
+
+                pRunningStr += 1;
+            }
+
+            // Find the end of the conversion name.
+            char* pConversionNameBeg = pRunningStr;
+            char* pConversionNameEnd = pConversionNameBeg;
+            for (;;) {
+                if (pConversionNameEnd[0] == '\0') return -1;
+                if (dr_is_whitespace(pConversionNameEnd[0])) {
+                    break;
+                }
+
+                pConversionNameEnd += 1;
+            }
+
+            pConversionNameEnd[0] = '\0';
+            pRunningStr = pConversionNameEnd;
+            pRunningStr += 1;
+
+            // Find the opening bracket.
+            for (;;) {
+                if (pRunningStr[0] == '\0') return -1;
+                if (pRunningStr[0] == '{') {
+                    currentFunc.formatInStr = pConversionNameBeg;
+                    char* formatInStrEnd = strstr((char*const)currentFunc.formatInStr, "->");
+                    formatInStrEnd[0] = '\0';
+                    currentFunc.formatOutStr = formatInStrEnd += 2;
+
+                    level += 1;
+                    break;
+                }
+
+                pRunningStr += 1;
+            }
+        } else if (level == 1) {
+            // Inside a function.
+
+            // Find the first non-whitespace which is where the first instruction should be located.
+            for (;;) {
+                if (pRunningStr[0] == '\0') return -1;
+                if (!dr_is_whitespace(pRunningStr[0])) {
+                    break;
+                }
+
+                pRunningStr += 1;
+            }
+
+            // Should be sitting at the name of the next instruction or the closing bracket.
+            if (pRunningStr[0] == '}') {
+                pContext->conversions.push_back(currentFunc);
+                currentFunc.formatInStr = NULL;
+                currentFunc.formatOutStr = NULL;
+                currentFunc.instructions.clear();
+                pRunningStr += 1;
+                level -= 1;
+                continue;
+            }
+
+            currentInst.name = pRunningStr;
+
+            // Get to the end of the name and null terminate it.
+            for (;;) {
+                if (pRunningStr[0] == '\0') return -1;
+                if (dr_is_whitespace(pRunningStr[0])) {
+                    break;
+                }
+                pRunningStr += 1;
+            }
+
+            pRunningStr[0] = '\0';
+            level += 1;
+        } else if (level == 2) {
+            // Inside an instruction.
+
+            // Find the first non-whitespace which is where the next parameter should be located.
+            for (;;) {
+                if (pRunningStr[0] == '\0') return -1;
+                if (!dr_is_whitespace(pRunningStr[0])) {
+                    break;
+                }
+                pRunningStr += 1;
+            }
+
+            currentInst.params[currentParam++] = pRunningStr;
+            currentInst.paramCount += 1;
+
+            // Should be sitting at the next parameter or the semi-colon.
+            if (pRunningStr[0] == ';') {
+                currentFunc.instructions.push_back(currentInst);
+                memset(&currentInst, 0, sizeof(currentInst));
+                currentParam = 0;
+                pRunningStr[0] = '\0';
+                pRunningStr += 1;
+                level -= 1;
+                continue;
+            }
+
+            // Get to the end of the name and null terminate it.
+            for (;;) {
+                if (pRunningStr[0] == '\0') return -1;
+                if (dr_is_whitespace(pRunningStr[0])) {
+                    break;
+                }
+
+                if (pRunningStr[0] == ';') {
+                    currentFunc.instructions.push_back(currentInst);
+                    memset(&currentInst, 0, sizeof(currentInst));
+                    currentParam = 0;
+                    pRunningStr[0] = '\0';
+                    pRunningStr += 1;
+                    level -= 1;
+                    break;
+                }
+
+                pRunningStr += 1;
+            }
+
+            pRunningStr[0] = '\0';
+        }
+
+        pRunningStr += 1;
+    }
+
+    return 0;
+}
+
+int main(int argc, char** argv)
+{
+    (void)argc;
+    (void)argv;
+
+    malgen_context context;
+    int result = malgen_compile(&context);
+    if (result != 0) {
+        return result;
+    }
+
+    FILE* pOutputFile = dr_fopen("malgen_test0.c", "w");
+    if (pOutputFile == NULL) {
+        printf("Failed to open output file.\n");
+        return -2;
+    }
+
+
+    // We need conversion routines for each different combination of formats.
+
+
+
+    // TESTING
+    for (size_t i = 0; i < context.conversions.size(); ++i) {
+        printf("%s to %s\n", context.conversions[i].formatInStr, context.conversions[i].formatOutStr);
+        for (size_t j = 0; j < context.conversions[i].instructions.size(); ++j) {
+            printf("   %s", context.conversions[i].instructions[j].name);
+            for (int k = 0; k < context.conversions[i].instructions[j].paramCount; ++k) {
+                printf(" %s", context.conversions[i].instructions[j].params[k]);
+            }
+            printf("\n");
+        }
+    }
+
+    return 0;
+}
\ No newline at end of file