Use MAT4_IDENTITY macro;

src/graphics/graphics.c

@@ -454,9 +454,7 @@ void lovrGraphicsDraw(DrawCommand* draw) {
   if (pose) {
     lovrShaderSetMatrices(shader, "lovrPose", pose, 0, MAX_BONES * 16);
   } else {
-    float identity[16];
-    mat4_identity(identity);
-    lovrShaderSetMatrices(shader, "lovrPose", identity, 0, 16);
+    lovrShaderSetMatrices(shader, "lovrPose", (float[16]) MAT4_IDENTITY, 0, 16);
   }
 
   lovrShaderSetInts(shader, "lovrViewportCount", &viewportCount, 0, 1);

src/graphics/model.c

@@ -158,8 +158,7 @@ void lovrModelDraw(Model* model, mat4 transform, int instances) {
     for (int i = 0; i < model->modelData->nodeCount; i++) {
       ModelNode* node = &model->modelData->nodes[i];
 
-      float localTransform[16];
-      mat4_identity(localTransform);
+      float localTransform[16] = MAT4_IDENTITY;
       if (!lovrAnimatorEvaluate(model->animator, node->name, localTransform)) {
         mat4_set(localTransform, node->transform);
       }

src/headset/fake.c

@@ -213,9 +213,8 @@ static void fakeRenderTo(void (*callback)(void*), void* userdata) {
   int width, height;
   fakeGetDisplayDimensions(&width, &height);
   bool stereo = state.mirrorEye == EYE_BOTH;
-  Camera camera = { .canvas = NULL, .stereo = stereo };
+  Camera camera = { .canvas = NULL, .viewMatrix = { MAT4_IDENTITY }, .stereo = stereo };
   mat4_perspective(camera.projection[0], state.clipNear, state.clipFar, 67 * M_PI / 180., (float) width / (1 + stereo) / height);
-  mat4_identity(camera.viewMatrix[0]);
   mat4_translate(camera.viewMatrix[0], 0, state.offset, 0);
   mat4_multiply(camera.viewMatrix[0], state.transform);
   mat4_invertPose(camera.viewMatrix[0]);

src/headset/openvr.c

@@ -541,7 +541,7 @@ static void openvrRenderTo(void (*callback)(void*), void* userdata) {
     lovrRelease(texture);
   }
 
-  Camera camera = { .canvas = state.canvas };
+  Camera camera = { .canvas = state.canvas, .viewMatrix = { MAT4_IDENTITY, MAT4_IDENTITY } };
 
   float head[16], eye[16];
   getTransform(HEADSET_INDEX, head);
@@ -549,7 +549,6 @@ static void openvrRenderTo(void (*callback)(void*), void* userdata) {
   for (int i = 0; i < 2; i++) {
     EVREye vrEye = (i == 0) ? EVREye_Eye_Left : EVREye_Eye_Right;
     mat4_fromMat44(camera.projection[i], state.system->GetProjectionMatrix(vrEye, state.clipNear, state.clipFar).m);
-    mat4_identity(camera.viewMatrix[i]);
     mat4_translate(camera.viewMatrix[i], 0, state.offset, 0);
     mat4_multiply(camera.viewMatrix[i], head);
     mat4_multiply(camera.viewMatrix[i], mat4_fromMat34(eye, state.system->GetEyeToHeadTransform(vrEye).m));

src/math/mat4.c

@@ -237,22 +237,13 @@ mat4 mat4_rotate(mat4 m, float angle, float x, float y, float z) {
 }
 
 mat4 mat4_rotateQuat(mat4 m, quat q) {
-  float x = q[0];
-  float y = q[1];
-  float z = q[2];
-  float w = q[3];
-  float rotation[16];
-  mat4_identity(rotation);
-  rotation[0] = 1 - 2 * y * y - 2 * z * z;
-  rotation[1] = 2 * x * y + 2 * w * z;
-  rotation[2] = 2 * x * z - 2 * w * y;
-  rotation[4] = 2 * x * y - 2 * w * z;
-  rotation[5] = 1 - 2 * x * x - 2 * z * z;
-  rotation[6] = 2 * y * z + 2 * w * x;
-  rotation[8] = 2 * x * z + 2 * w * y;
-  rotation[9] = 2 * y * z - 2 * w * x;
-  rotation[10] = 1 - 2 * x * x - 2 * y * y;
-  return mat4_multiply(m, rotation);
+  float x = q[0], y = q[1], z = q[2], w = q[3];
+  return mat4_multiply(m, (float[16]) {
+    1 - 2 * y * y - 2 * z * z, 2 * x * y + 2 * w * z, 2 * x * z - 2 * w * y, 0,
+    2 * x * y - 2 * w * z, 1 - 2 * x * x - 2 * z * z, 2 * y * z + 2 * w * x, 0,
+    2 * x * z + 2 * w * y, 2 * y * z - 2 * w * x, 1 - 2 * x * x - 2 * y * y, 0,
+    0, 0, 0, 1
+  });
 }
 
 mat4 mat4_scale(mat4 m, float x, float y, float z) {

src/math/mat4.h

@@ -2,6 +2,8 @@
 
 #pragma once
 
+#define MAT4_IDENTITY { 1, 0, 0, 0,  0, 1, 0, 0,  0, 0, 1, 0,  0, 0, 0, 1 }
+
 #define mat4_init mat4_set
 mat4 mat4_set(mat4 m, mat4 n);
 mat4 mat4_fromMat34(mat4 m, float (*n)[4]);