From a04e5013adb28d3db840ff9ca7ee2404577abf75 Mon Sep 17 00:00:00 2001
From: bjorn <tie.372@gmail.com>
Date: Fri, 31 Mar 2017 04:22:18 -0700
Subject: [PATCH] lovr.graphics.getSystemLimits;

---
 src/api/graphics.c      | 12 ++++++++++++
 src/graphics/graphics.c | 40 +++++++++++++++++++++++++++++++---------
 src/graphics/graphics.h | 10 ++++++++++
 3 files changed, 53 insertions(+), 9 deletions(-)

diff --git a/src/api/graphics.c b/src/api/graphics.c
index 043db7c1..d6fd6a37 100644
--- a/src/api/graphics.c
+++ b/src/api/graphics.c
@@ -406,6 +406,17 @@ int l_lovrGraphicsGetDimensions(lua_State* L) {
   return 2;
 }
 
+int l_lovrGraphicsGetSystemLimits(lua_State* L) {
+  lua_newtable(L);
+  lua_pushnumber(L, lovrGraphicsGetSystemLimit(LIMIT_POINT_SIZE));
+  lua_setfield(L, -2, "pointsize");
+  lua_pushinteger(L, lovrGraphicsGetSystemLimit(LIMIT_TEXTURE_SIZE));
+  lua_setfield(L, -2, "texturesize");
+  lua_pushinteger(L, lovrGraphicsGetSystemLimit(LIMIT_TEXTURE_MSAA));
+  lua_setfield(L, -2, "texturemsaa");
+  return 1;
+}
+
 // Transforms
 
 int l_lovrGraphicsPush(lua_State* L) {
@@ -800,6 +811,7 @@ const luaL_Reg lovrGraphics[] = {
   { "getWidth", l_lovrGraphicsGetWidth },
   { "getHeight", l_lovrGraphicsGetHeight },
   { "getDimensions", l_lovrGraphicsGetDimensions },
+  { "getSystemLimits", l_lovrGraphicsGetSystemLimits },
   { "newFont", l_lovrGraphicsNewFont },
   { "newMesh", l_lovrGraphicsNewMesh },
   { "newModel", l_lovrGraphicsNewModel },
diff --git a/src/graphics/graphics.c b/src/graphics/graphics.c
index d931404d..9923a2a6 100644
--- a/src/graphics/graphics.c
+++ b/src/graphics/graphics.c
@@ -14,23 +14,36 @@ static GraphicsState state;
 // Base
 
 void lovrGraphicsInit() {
-  for (int i = 0; i < MAX_CANVASES; i++) {
-    state.canvases[i] = malloc(sizeof(CanvasState));
-  }
-  state.defaultShader = lovrShaderCreate(lovrDefaultVertexShader, lovrDefaultFragmentShader);
-  state.skyboxShader = lovrShaderCreate(lovrSkyboxVertexShader, lovrSkyboxFragmentShader);
-  int uniformId = lovrShaderGetUniformId(state.skyboxShader, "cube");
-  lovrShaderSendInt(state.skyboxShader, uniformId, 1);
-  state.fullscreenShader = lovrShaderCreate(lovrNoopVertexShader, lovrDefaultFragmentShader);
+
+  // Allocations
   state.activeFont = NULL;
   state.defaultFont = NULL;
   state.activeTexture = NULL;
-  state.defaultTexture = lovrTextureCreate(lovrTextureDataGetBlank(1, 1, 0xff, FORMAT_RGBA));
   glGenBuffers(1, &state.shapeBuffer);
   glGenBuffers(1, &state.shapeIndexBuffer);
   glGenVertexArrays(1, &state.shapeArray);
   vec_init(&state.shapeData);
   vec_init(&state.shapeIndices);
+  for (int i = 0; i < MAX_CANVASES; i++) {
+    state.canvases[i] = malloc(sizeof(CanvasState));
+  }
+
+  // Objects
+  state.defaultShader = lovrShaderCreate(lovrDefaultVertexShader, lovrDefaultFragmentShader);
+  state.skyboxShader = lovrShaderCreate(lovrSkyboxVertexShader, lovrSkyboxFragmentShader);
+  int uniformId = lovrShaderGetUniformId(state.skyboxShader, "cube");
+  lovrShaderSendInt(state.skyboxShader, uniformId, 1);
+  state.fullscreenShader = lovrShaderCreate(lovrNoopVertexShader, lovrDefaultFragmentShader);
+  state.defaultTexture = lovrTextureCreate(lovrTextureDataGetBlank(1, 1, 0xff, FORMAT_RGBA));
+
+  // System Limits
+  float pointSizes[2];
+  glGetFloatv(GL_POINT_SIZE_RANGE, pointSizes);
+  state.maxPointSize = pointSizes[1];
+  glGetIntegerv(GL_MAX_TEXTURE_SIZE, &state.maxTextureSize);
+  glGetIntegerv(GL_MAX_SAMPLES, &state.maxTextureMSAA);
+
+  // State
   state.depthTest = -1;
   lovrGraphicsReset();
   atexit(lovrGraphicsDestroy);
@@ -378,6 +391,15 @@ int lovrGraphicsGetHeight() {
   return height;
 }
 
+float lovrGraphicsGetSystemLimit(GraphicsLimit limit) {
+  switch (limit) {
+    case LIMIT_POINT_SIZE: return state.maxPointSize;
+    case LIMIT_TEXTURE_SIZE: return state.maxTextureSize;
+    case LIMIT_TEXTURE_MSAA: return state.maxTextureMSAA;
+    default: error("Unknown limit %d\n", limit);
+  }
+}
+
 void lovrGraphicsPushCanvas() {
   if (++state.canvas >= MAX_CANVASES) {
     error("Canvas overflow");
diff --git a/src/graphics/graphics.h b/src/graphics/graphics.h
index 45c315b5..1873e194 100644
--- a/src/graphics/graphics.h
+++ b/src/graphics/graphics.h
@@ -47,6 +47,12 @@ typedef enum {
   COMPARE_GREATER = GL_GREATER
 } CompareMode;
 
+typedef enum {
+  LIMIT_POINT_SIZE,
+  LIMIT_TEXTURE_SIZE,
+  LIMIT_TEXTURE_MSAA
+} GraphicsLimit;
+
 typedef struct {
   int x;
   int y;
@@ -90,6 +96,9 @@ typedef struct {
   PolygonWinding polygonWinding;
   CompareMode depthTest;
   int isWireframe;
+  float maxPointSize;
+  int maxTextureSize;
+  int maxTextureMSAA;
 } GraphicsState;
 
 // Base
@@ -137,6 +146,7 @@ int lovrGraphicsIsWireframe();
 void lovrGraphicsSetWireframe(int wireframe);
 int lovrGraphicsGetWidth();
 int lovrGraphicsGetHeight();
+float lovrGraphicsGetSystemLimit(GraphicsLimit limit);
 void lovrGraphicsPushCanvas();
 void lovrGraphicsPopCanvas();
 void lovrGraphicsSetViewport(int x, int y, int w, int h);