CanvasState;

src/graphics/graphics.c

@@ -17,7 +17,9 @@ void lovrGraphicsInit() {
   for (int i = 0; i < MAX_TRANSFORMS; i++) {
     state.transforms[i] = mat4_init();
   }
-  state.projection = mat4_init();
+  state.canvases[0].framebuffer = 0;
+  glGetIntegerv(GL_VIEWPORT, state.canvases[0].viewport);
+  state.canvases[0].isSystem = 1;
   state.defaultShader = lovrShaderCreate(lovrDefaultVertexShader, lovrDefaultFragmentShader);
   state.skyboxShader = lovrShaderCreate(lovrSkyboxVertexShader, lovrSkyboxFragmentShader);
   int uniformId = lovrShaderGetUniformId(state.skyboxShader, "cube");
@@ -38,7 +40,6 @@ void lovrGraphicsDestroy() {
   for (int i = 0; i < MAX_TRANSFORMS; i++) {
     mat4_deinit(state.transforms[i]);
   }
-  mat4_deinit(state.projection);
   lovrRelease(&state.defaultShader->ref);
   lovrRelease(&state.skyboxShader->ref);
   lovrRelease(&state.defaultTexture->ref);
@@ -51,6 +52,7 @@ void lovrGraphicsDestroy() {
 
 void lovrGraphicsReset() {
   state.transform = 0;
+  state.canvas = 0;
   lovrGraphicsSetProjection(.1f, 100.f, 67 * M_PI / 180); // TODO customize via lovr.conf
   lovrGraphicsSetShader(NULL);
   lovrGraphicsBindTexture(NULL);
@@ -86,7 +88,9 @@ void lovrGraphicsPresent() {
 
 void lovrGraphicsPrepare() {
   Shader* shader = lovrGraphicsGetShader();
-  lovrShaderBind(shader, state.transforms[state.transform], state.projection, state.color, 0);
+  mat4 transform = state.transforms[state.transform];
+  mat4 projection = state.canvases[state.canvas].projection;
+  lovrShaderBind(shader, transform, projection, state.color, 0);
 }
 
 // State
@@ -188,11 +192,7 @@ void lovrGraphicsBindTexture(Texture* texture) {
 void lovrGraphicsSetProjection(float near, float far, float fov) {
   int width, height;
   glfwGetWindowSize(window, &width, &height);
-  mat4_setProjection(state.projection, near, far, fov, (float) width / height);
+  mat4_setProjection(state.canvases[state.canvas].projection, near, far, fov, (float) width / height);
-}
-
-void lovrGraphicsSetProjectionRaw(mat4 projection) {
-  memcpy(state.projection, projection, 16 * sizeof(float));
 }
 
 float lovrGraphicsGetLineWidth() {
@@ -274,6 +274,30 @@ int lovrGraphicsGetHeight() {
   return height;
 }
 
+void lovrGraphicsPushCanvas(CanvasState canvasState) {
+  if (!canvasState.isSystem && !state.canvases[state.canvas].isSystem) {
+    lovrGraphicsPopCanvas();
+  } else if (++state.canvas >= MAX_CANVASES) {
+    error("Canvas overflow");
+  }
+
+  int* viewport = canvasState.viewport;
+  glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);
+  glBindFramebuffer(GL_FRAMEBUFFER, canvasState.framebuffer);
+  state.canvases[state.canvas] = canvasState;
+}
+
+void lovrGraphicsPopCanvas() {
+  if (--state.canvas < 0) {
+    error("Canvas underflow");
+  }
+
+  CanvasState* canvasState = &state.canvases[state.canvas];
+  int* viewport = canvasState->viewport;
+  glViewport(viewport[0], viewport[1], viewport[2], viewport[3]);
+  glBindFramebuffer(GL_FRAMEBUFFER, canvasState->framebuffer);
+}
+
 // Transforms
 
 int lovrGraphicsPush() {

src/graphics/graphics.h

@@ -9,13 +9,7 @@
 #define LOVR_GRAPHICS_TYPES
 
 #define MAX_TRANSFORMS 64
-
+#define MAX_CANVASES 4
-typedef struct {
-  int x;
-  int y;
-  int width;
-  int height;
-} ScissorRectangle;
 
 typedef enum {
   DRAW_MODE_FILL,
@@ -37,6 +31,20 @@ typedef enum {
   COMPARE_GREATER = GL_GREATER
 } CompareMode;
 
+typedef struct {
+  int x;
+  int y;
+  int width;
+  int height;
+} ScissorRectangle;
+
+typedef struct CanvasState {
+  int framebuffer;
+  float projection[16];
+  int viewport[4];
+  int isSystem;
+} CanvasState;
+
 typedef struct {
   Shader* activeShader;
   Shader* defaultShader;
@@ -44,7 +52,8 @@ typedef struct {
   Texture* defaultTexture;
   int transform;
   mat4 transforms[MAX_TRANSFORMS];
-  mat4 projection;
+  int canvas;
+  CanvasState canvases[MAX_CANVASES];
   unsigned int color;
   char colorMask;
   int isScissorEnabled;
@@ -87,7 +96,6 @@ Shader* lovrGraphicsGetShader();
 void lovrGraphicsSetShader(Shader* shader);
 void lovrGraphicsBindTexture(Texture* texture);
 void lovrGraphicsSetProjection(float near, float far, float fov);
-void lovrGraphicsSetProjectionRaw(mat4 projection);
 float lovrGraphicsGetLineWidth();
 void lovrGraphicsSetLineWidth(float width);
 float lovrGraphicsGetPointSize();
@@ -102,6 +110,8 @@ int lovrGraphicsIsWireframe();
 void lovrGraphicsSetWireframe(int wireframe);
 int lovrGraphicsGetWidth();
 int lovrGraphicsGetHeight();
+void lovrGraphicsPushCanvas(CanvasState canvasState);
+void lovrGraphicsPopCanvas();
 
 // Transforms
 int lovrGraphicsPush();

src/graphics/texture.c

@@ -1,4 +1,5 @@
 #include "graphics/texture.h"
+#include "graphics/graphics.h"
 #include "util.h"
 #include <stdlib.h>
 
@@ -47,6 +48,22 @@ void lovrTextureBind(Texture* texture) {
   glBindTexture(GL_TEXTURE_2D, texture->id);
 }
 
+CanvasState lovrTextureGetCanvasState(Texture* texture) {
+  if (!texture->fbo) {
+    error("Texture cannot be used as a canvas");
+  }
+
+  CanvasState canvasState = {
+    .framebuffer = texture->fbo,
+    .viewport = { 0, 0, texture->width, texture->height },
+    .isSystem = 0
+  };
+
+  mat4_setIdentity(canvasState.projection); // TODO
+
+  return canvasState;
+}
+
 int lovrTextureGetHeight(Texture* texture) {
   return texture->height;
 }
@@ -60,20 +77,6 @@ void lovrTextureGetFilter(Texture* texture, FilterMode* min, FilterMode* mag) {
   *mag = texture->filterMag;
 }
 
-void lovrTextureRenderTo(Texture* texture, textureRenderCallback callback, void* userdata) {
-  if (!texture->fbo) {
-    error("Texture does not have a framebuffer");
-  }
-
-  int oldViewport[4];
-  glGetIntegerv(GL_VIEWPORT, oldViewport);
-  glViewport(0, 0, texture->textureData->width, texture->textureData->height);
-  glBindFramebuffer(GL_FRAMEBUFFER, texture->fbo);
-  callback(userdata);
-  glBindFramebuffer(GL_FRAMEBUFFER, 0);
-  glViewport(oldViewport[0], oldViewport[1], oldViewport[2], oldViewport[3]);
-}
-
 void lovrTextureSetFilter(Texture* texture, FilterMode min, FilterMode mag) {
   texture->filterMin = min;
   texture->filterMag = mag;

src/graphics/texture.h

@@ -1,13 +1,11 @@
 #include "glfw.h"
 #include "util.h"
 
-struct Buffer;
+struct CanvasState;
 
 #ifndef LOVR_TEXTURE_TYPES
 #define LOVR_TEXTURE_TYPES
 
-typedef void (*textureRenderCallback)(void*);
-
 typedef struct {
   void* data;
   int width;
@@ -27,11 +25,17 @@ typedef enum {
   WRAP_CLAMP_ZERO = GL_CLAMP_TO_BORDER
 } WrapMode;
 
+typedef enum {
+  PROJECTION_ORTHOGRAPHIC,
+  PROJECTION_PERSPECTIVE
+} ProjectionType;
+
 typedef struct {
   Ref ref;
   TextureData* textureData;
   GLuint id;
   GLuint fbo;
+  ProjectionType projectionType;
   int width;
   int height;
   FilterMode filterMin;
@@ -46,10 +50,10 @@ Texture* lovrTextureCreate(TextureData* textureData, int hasFramebuffer);
 void lovrTextureDestroy(const Ref* ref);
 void lovrTextureDataDestroy(TextureData* textureData);
 void lovrTextureBind(Texture* texture);
+struct CanvasState lovrTextureGetCanvasState(Texture* texture);
 void lovrTextureRefresh(Texture* texture);
 int lovrTextureGetHeight(Texture* texture);
 int lovrTextureGetWidth(Texture* texture);
-void lovrTextureRenderTo(Texture* texture, textureRenderCallback callback, void* userdata);
 void lovrTextureGetFilter(Texture* texture, FilterMode* min, FilterMode* mag);
 void lovrTextureSetFilter(Texture* texture, FilterMode min, FilterMode mag);
 void lovrTextureGetWrap(Texture* texture, WrapMode* horizontal, WrapMode* vertical);

src/headset/vive.c

@@ -484,7 +484,12 @@ void* viveControllerGetModel(void* headset, Controller* controller, ControllerMo
 
 void viveRenderTo(void* headset, headsetRenderCallback callback, void* userdata) {
   Vive* vive = (Vive*) headset;
-  float headMatrix[16], eyeMatrix[16], projectionMatrix[16];
+  CanvasState canvasState = {
+    .framebuffer = vive->framebuffer,
+    .viewport = { 0, 0, vive->renderWidth, vive->renderHeight },
+    .isSystem = 1
+  };
+  float headMatrix[16], eyeMatrix[16];
   float (*matrix)[4];
 
   vive->isRendering = 1;
@@ -502,21 +507,19 @@ void viveRenderTo(void* headset, headsetRenderCallback callback, void* userdata)
     float near = vive->clipNear;
     float far = vive->clipFar;
     matrix = vive->system->GetProjectionMatrix(eye, near, far).m;
-    mat4_fromMat44(projectionMatrix, matrix);
+    mat4_fromMat44(canvasState.projection, matrix);
 
     glEnable(GL_MULTISAMPLE);
-    glBindFramebuffer(GL_FRAMEBUFFER, vive->framebuffer);
-    glViewport(0, 0, vive->renderWidth, vive->renderHeight);
 
+    lovrGraphicsPushCanvas(canvasState);
     lovrGraphicsClear(1, 1);
     lovrGraphicsPush();
     lovrGraphicsOrigin();
     lovrGraphicsMatrixTransform(transformMatrix);
-    lovrGraphicsSetProjectionRaw(projectionMatrix);
     callback(i, userdata);
     lovrGraphicsPop();
+    lovrGraphicsPopCanvas();
 
-    glBindFramebuffer(GL_FRAMEBUFFER, 0);
     glDisable(GL_MULTISAMPLE);
 
     glBindFramebuffer(GL_READ_FRAMEBUFFER, vive->framebuffer);

src/lovr/types/texture.c

@@ -1,5 +1,6 @@
 #include "lovr/types/texture.h"
 #include "lovr/graphics.h"
+#include "graphics/graphics.h"
 #include "util.h"
 
 const luaL_Reg lovrTexture[] = {
@@ -15,12 +16,6 @@ const luaL_Reg lovrTexture[] = {
   { NULL, NULL }
 };
 
-static void renderHelper(void* userdata) {
-  lua_State* L = (lua_State*) userdata;
-  luaL_checktype(L, -1, LUA_TFUNCTION);
-  lua_call(L, 0, 0);
-}
-
 int l_lovrTextureBind(lua_State* L) {
   Texture* texture = luax_checktype(L, 1, Texture);
   lovrTextureBind(texture);
@@ -66,8 +61,10 @@ int l_lovrTextureGetWrap(lua_State* L) {
 
 int l_lovrTextureRenderTo(lua_State* L) {
   Texture* texture = luax_checktype(L, 1, Texture);
+  lovrGraphicsPushCanvas(lovrTextureGetCanvasState(texture));
   lua_settop(L, 2);
-  lovrTextureRenderTo(texture, renderHelper, L);
+  lua_call(L, 0, 0);
+  lovrGraphicsPopCanvas();
   return 0;
 }