Transform stack;

src/api/api.h

@@ -53,6 +53,7 @@ extern StringEntry lovrSampleFormat[];
 extern StringEntry lovrShaderType[];
 extern StringEntry lovrShapeType[];
 extern StringEntry lovrSmoothMode[];
+extern StringEntry lovrStackType[];
 extern StringEntry lovrStencilAction[];
 extern StringEntry lovrTextureFeature[];
 extern StringEntry lovrTextureFormat[];

src/api/l_graphics.c

@@ -75,6 +75,12 @@ StringEntry lovrPassType[] = {
   { 0 }
 };
 
+StringEntry lovrStackType[] = {
+  [STACK_TRANSFORM] = ENTRY("transform"),
+  [STACK_PIPELINE] = ENTRY("pipeline"),
+  { 0 }
+};
+
 StringEntry lovrTextureFeature[] = {
   [0] = ENTRY("sample"),
   [1] = ENTRY("filter"),

src/api/l_graphics_pass.c

@@ -11,7 +11,66 @@ static int l_lovrPassGetType(lua_State* L) {
   return 1;
 }
 
+static int l_lovrPassPush(lua_State* L) {
+  Pass* pass = luax_checktype(L, 1, Pass);
+  StackType stack = luax_checkenum(L, 2, StackType, "transform");
+  lovrPassPush(pass, stack);
+  return 0;
+}
+
+static int l_lovrPassPop(lua_State* L) {
+  Pass* pass = luax_checktype(L, 1, Pass);
+  StackType stack = luax_checkenum(L, 2, StackType, "transform");
+  lovrPassPop(pass, stack);
+  return 0;
+}
+
+static int l_lovrPassOrigin(lua_State* L) {
+  Pass* pass = luax_checktype(L, 1, Pass);
+  lovrPassOrigin(pass);
+  return 0;
+}
+
+static int l_lovrPassTranslate(lua_State* L) {
+  float translation[4];
+  Pass* pass = luax_checktype(L, 2, Pass);
+  luax_readvec3(L, 1, translation, NULL);
+  lovrPassTranslate(pass, translation);
+  return 0;
+}
+
+static int l_lovrPassRotate(lua_State* L) {
+  float rotation[4];
+  Pass* pass = luax_checktype(L, 1, Pass);
+  luax_readquat(L, 2, rotation, NULL);
+  lovrPassRotate(pass, rotation);
+  return 0;
+}
+
+static int l_lovrPassScale(lua_State* L) {
+  float scale[4];
+  Pass* pass = luax_checktype(L, 1, Pass);
+  luax_readscale(L, 2, scale, 3, NULL);
+  lovrPassScale(pass, scale);
+  return 0;
+}
+
+static int l_lovrPassTransform(lua_State* L) {
+  float transform[16];
+  Pass* pass = luax_checktype(L, 1, Pass);
+  luax_readmat4(L, 2, transform, 3);
+  lovrPassTransform(pass, transform);
+  return 0;
+}
+
 const luaL_Reg lovrPass[] = {
   { "getType", l_lovrPassGetType },
+  { "push", l_lovrPassPush },
+  { "pop", l_lovrPassPop },
+  { "origin", l_lovrPassOrigin },
+  { "translate", l_lovrPassTranslate },
+  { "rotate", l_lovrPassRotate },
+  { "scale", l_lovrPassScale },
+  { "transform", l_lovrPassTransform },
   { NULL, NULL }
 };

src/modules/graphics/graphics.c

@@ -1,6 +1,7 @@
 #include "graphics/graphics.h"
 #include "data/image.h"
 #include "core/gpu.h"
+#include "core/maf.h"
 #include "core/os.h"
 #include "util.h"
 #include <math.h>
@@ -34,6 +35,9 @@ struct Pass {
   uint32_t ref;
   PassInfo info;
   gpu_stream* stream;
+  float* transform;
+  uint32_t transformIndex;
+  float transforms[16][16];
 };
 
 typedef struct {
@@ -523,6 +527,43 @@ const PassInfo* lovrPassGetInfo(Pass* pass) {
   return &pass->info;
 }
 
+void lovrPassPush(Pass* pass, StackType stack) {
+  lovrCheck(pass->info.type == PASS_RENDER, "This function can only be called on a render pass");
+  if (stack == STACK_TRANSFORM) {
+    pass->transform = pass->transforms[++pass->transformIndex];
+    lovrCheck(pass->transformIndex < COUNTOF(pass->transforms), "Transform stack overflow (more pushes than pops?)");
+    mat4_init(pass->transforms[pass->transformIndex], pass->transforms[pass->transformIndex - 1]);
+  }
+}
+
+void lovrPassPop(Pass* pass, StackType stack) {
+  lovrCheck(pass->info.type == PASS_RENDER, "This function can only be called on a render pass");
+  if (stack == STACK_TRANSFORM) {
+    pass->transform = pass->transforms[--pass->transformIndex];
+    lovrCheck(pass->transformIndex < COUNTOF(pass->transforms), "Transform stack underflow (more pops than pushes?)");
+  }
+}
+
+void lovrPassOrigin(Pass* pass) {
+  mat4_identity(pass->transform);
+}
+
+void lovrPassTranslate(Pass* pass, vec3 translation) {
+  mat4_translate(pass->transform, translation[0], translation[1], translation[2]);
+}
+
+void lovrPassRotate(Pass* pass, quat rotation) {
+  mat4_rotateQuat(pass->transform, rotation);
+}
+
+void lovrPassScale(Pass* pass, vec3 scale) {
+  mat4_scale(pass->transform, scale[0], scale[1], scale[2]);
+}
+
+void lovrPassTransform(Pass* pass, mat4 transform) {
+  mat4_mul(pass->transform, transform);
+}
+
 // Helpers
 
 static void* tempAlloc(size_t size) {

src/modules/graphics/graphics.h

@@ -236,6 +236,11 @@ typedef enum {
   PASS_TRANSFER
 } PassType;
 
+typedef enum {
+  STACK_TRANSFORM,
+  STACK_PIPELINE
+} StackType;
+
 typedef enum {
   LOAD_KEEP,
   LOAD_CLEAR,
@@ -266,3 +271,12 @@ typedef struct {
 Pass* lovrGraphicsGetPass(PassInfo* info);
 void lovrPassDestroy(void* ref);
 const PassInfo* lovrPassGetInfo(Pass* pass);
+
+// Render
+void lovrPassPush(Pass* pass, StackType stack);
+void lovrPassPop(Pass* pass, StackType stack);
+void lovrPassOrigin(Pass* pass);
+void lovrPassTranslate(Pass* pass, float* translation);
+void lovrPassRotate(Pass* pass, float* rotation);
+void lovrPassScale(Pass* pass, float* scale);
+void lovrPassTransform(Pass* pass, float* transform);