Add index16/index32 FieldTypes;

Similar to u16/u32 but are 1-indexed when written using tables.

src/api/l_graphics.c

@@ -106,6 +106,8 @@ StringEntry lovrFieldType[] = {
   [FIELD_MAT2] = ENTRY("mat2"),
   [FIELD_MAT3] = ENTRY("mat3"),
   [FIELD_MAT4] = ENTRY("mat4"),
+  [FIELD_INDEX16] = ENTRY("index16"),
+  [FIELD_INDEX32] = ENTRY("index32"),
   { 0 }
 };
 
@@ -245,7 +247,9 @@ static struct { uint32_t size, scalarAlign, baseAlign, components; } fieldInfo[]
   [FIELD_F32x4] = { 16, 4, 16, 4 },
   [FIELD_MAT2] = { 16, 4, 8, 4 },
   [FIELD_MAT3] = { 64, 4, 16, 9 },
-  [FIELD_MAT4] = { 64, 4, 16, 16 }
+  [FIELD_MAT4] = { 64, 4, 16, 16 },
+  [FIELD_INDEX16] = { 2, 2, 2, 1 },
+  [FIELD_INDEX32] = { 4, 4, 4, 1 }
 };
 
 static uint32_t luax_checkfieldtype(lua_State* L, int index, uint32_t* nameHash) {
@@ -296,6 +300,10 @@ static uint32_t luax_checkfieldtype(lua_State* L, int index, uint32_t* nameHash)
     return FIELD_UN8x4;
   }
 
+  if (length == 6 && !memcmp(string, "index", length)) {
+    return FIELD_INDEX32;
+  }
+
   for (int i = 0; lovrFieldType[i].length; i++) {
     if (length == lovrFieldType[i].length && !memcmp(string, lovrFieldType[i].string, length)) {
       return i;

src/api/l_graphics_buffer.c

@@ -47,7 +47,9 @@ static const uint32_t fieldComponents[] = {
   [FIELD_F32x4] = 4,
   [FIELD_MAT2] = 4,
   [FIELD_MAT3] = 9,
-  [FIELD_MAT4] = 16
+  [FIELD_MAT4] = 16,
+  [FIELD_INDEX16] = 1,
+  [FIELD_INDEX32] = 1
 };
 
 typedef union {
@@ -131,6 +133,8 @@ void luax_readbufferfield(lua_State* L, int index, int type, void* data) {
         case FIELD_MAT2: p.f32[i] = (float) x; break;
         case FIELD_MAT3: p.f32[i] = (float) x; break;
         case FIELD_MAT4: p.f32[i] = (float) x; break;
+        case FIELD_INDEX16: p.u16[i] = (uint16_t) x - 1; break;
+        case FIELD_INDEX32: p.u32[i] = (uint32_t) x - 1; break;
         default: lovrUnreachable();
       }
     }

src/modules/graphics/graphics.c

@@ -2342,7 +2342,7 @@ Model* lovrModelCreate(ModelInfo* info) {
       .length = data->indexCount,
       .stride = indexSize,
       .fieldCount = 1,
-      .fields[0] = { 0, 0, data->indexType == U32 ? FIELD_U32 : FIELD_I32, 0 }
+      .fields[0] = { 0, 0, data->indexType == U32 ? FIELD_INDEX32 : FIELD_INDEX16, 0 }
     }, (void**) &indices);
   }
 
@@ -3435,6 +3435,7 @@ static void flushPipeline(Pass* pass, Draw* draw, Shader* shader) {
       bool found = false;
       for (uint32_t j = 0; j < draw->vertex.buffer->info.fieldCount; j++) {
         BufferField field = draw->vertex.buffer->info.fields[j];
+        lovrCheck(field.type < FIELD_MAT2, "Currently, matrix and index types can not be used in vertex buffers");
         if (field.hash ? (field.hash == attribute->hash) : (field.location == attribute->location)) {
           pipeline->info.vertex.attributes[i] = (gpu_attribute) {
             .buffer = 0,

src/modules/graphics/graphics.h

@@ -138,7 +138,9 @@ typedef enum {
   FIELD_F32x4,
   FIELD_MAT2,
   FIELD_MAT3,
-  FIELD_MAT4
+  FIELD_MAT4,
+  FIELD_INDEX16,
+  FIELD_INDEX32
 } FieldType;
 
 typedef struct {